I've looked everywhere. No one seems to have posted them. What are they?
Right now I'm a bit confused. Since this is an awesome device you'd think it would be fast in every aspect. It is, except for USB file transfers.
I'm running on Windows 7 Ultimate. I backed up everything from my phone to the computer with a data transfer rate from the SD card, in the phone, of 4.5MB/s. I then formatted the card (read earlier that this would help with the HD2 lock-ups) and copied everything back onto the SD card in the same fashion, through the phone. The data transfer back is right around 2.5 MB/s.... ???
I've tested all the ports around the computer, each are about the same. Anyone have any idea on how to fix this?
First thing would be to tell what kind and class of microSD card you have...
That would really depend on your SD card "class".
The higher the class, the faster it is capable of performing reading and writing operations.
But it's better to avoid the 16GB cards... the larger capacity cards take much longer to read... regardless of classifications or brand.
Something like a 4GB - Class 6 card is excellent.
I've read that it's only a class 2 MicroSD. Do you guys know where I can get class 4, or even a class 6 MicroSD? Whichever I get however depends on the max speed of the HD2. For example, I don't want to buy a class 6 and find out that the HD2 can only handle speeds up to the class 4. There is a $30-$40 USD difference.
Thanks for the SD info, it definitely helps. But now we're brought back to my original question. What are the max transfer speeds through the phone onto/from the MicroSD card? Has anyone found out?
personally i wouldn't do large data backups through activesync/MDC with the card still in the phone.
its simple to remove the card and put it in the supplied adapter card for use with sd_readers.
i bought a usb1.1 reader from a 'pound' shop, copying large files takes alot less time (average 10-11mb/sec) with my more expensive usb2.0 reader its even faster (average 50-60mb/sec)
card class does make a difference, but then so does sending large amounts of data through a 'middle man' like activesync or device center.
budget SD reader FTW
That is a good point, and I agree is faster than through the phone. For me though I have a few accessories on the phone which make taking the SD card out quite a pain.
I have an invisishield on the screen, and a poly-something or other high density plastic cover to replace the cover that came with the phone,-- It grips around the HD2 tightly. The cover is wonderful, but it tends to interfere with the invisishield. So if I am continually taking the cover on and off to get the SD card out I will eventually bend up the edges of the invisishield and will need to get that replaced.
In my best attempts to keep the phone nice I'm going to have to stick with whatever input/output the HD2-to/from-SD can give me.
choosing disk drive mode rather than active sync is the easiest way to speed up file transfers.
re: the figures you gave in post 1, write is always slower than read.
Forgot to mention, it was in 'disk drive mode'.
Btw, I found that the HTC HD2 is USB 2.0 Hi-Speed capable out-of-box. (I'd post a link, but forums wont let me, being new), and Hi-Speed USB can transfer 480Mbits/s, or ~57MB/s (Wikipedia, Universal Serial Bus, Signaling).
The Class 6 MicroSD card can write 48Mbits/s, or 6MB/s (Wikipedia, Secure Digital, Speeds). Easily obtained for the HD2.
Assuming this is everything that needs to be dealt with, this should work out wonderfully. I'll be writing files 300% faster with a class 6, and reading a whole lot faster (thanks Samsamuel, forgot about that read/write differences). Question is though, is this all? Or do I need to install some hi-speed usb driver on the computer? Or are there other things I'm not seeing that need to be dealt with?
its also worth remembering when you are doing the maths that USB loses around 25/35% to networking overhead. (the data that makes up the packet that holds the data you are transferring)
So, 480 Mbit = 60MBytes total = around 35Mbytes actual data transferred per second. (Results vary depending on the system, the cable, all kinds of things, but 30-35 is average, a little more in a testbed situation.
So I guess I'll just have to suffer with 219% faster instead of 300%... Well, looks like I'm returning the HD2!
Related
I havent looked too deeply into this, preferring to ask like .. So please don't eat me.
Its late and all ..
I'm wondering what speed the SD card reader in the Universal is?
Is it worth spending a little extra on some 60x Corsair SD cards or should I just get the bargain bin stuff since the Universal maybe doesnt have a particularly quick card reader?
Any advice welcome. I plan to use this is a system disk with seperate 512 card for my MP3's and pod casts/documents. THAT will be cheap stuff.
But for the main I need a 1gb system disk for storing apps and system stuff.
Compared to a dedicated USB card reader for the PC, the Universal is extremely slow - I have tested this with my 150X 2GB SD card. So unless you plan on using it with a PC card reader, it doesn't really matter
Accessing the SD card through activesync was at least 10 times slower than the card reader...
I did a small test with Pocket Mechanic.
1. My "normal" 2 GB sandisk gives 0.84MB/sec
2. My super duper Extreme III Sandisk 1 GB gives me a whopping 0.88MB sec.
Nr . 2 card, in my portable, writes files much, much faster than nr.1.
You can see however that in my Jasjar the difference is nearly zero.
I would say: go for the cheapest, but I am not a great technician.
Huib
Thanks guys ..
Very informative and will help me get the right card. ie. the cheapest!
-Gubbs
Hi
I have not noticed any difference between a basic Sandisk card and a so called 66x KingMax card when used in the exec.
I do notice a difference between these two cards when using them with my digicam - the multishot mode (2 frames/sec) actually works cause the camera is able to write to the card quickly enough. With the slow card, cam kept pausing to write its cache onto the card.
I am not sure that pocket mechanic tells the truth! Likewise, timing a copy from the internal flash to an SD card is not gonna give accurate results (speed of internal flash may be bottleneck). On Wm2003 devices this was possible cause RAM is loads faster than flash still.
You cant test the speed of the SD reader in the exec over activesync tho!! Its a USB 1.1 device (max 11Mbit) and on top of that activesync treats it as a 10Mbit network card. Max you'll see after overheads is thus around 1MByte/sec
Nigel
veletron said:
Hi
You cant test the speed of the SD reader in the exec over activesync tho!! Its a USB 1.1 device (max 11Mbit) and on top of that activesync treats it as a 10Mbit network card. Max you'll see after overheads is thus around 1MByte/sec
Nigel
Click to expand...
Click to collapse
Certainly much better to do it that way.
Huib
ok i m having problem to decide as well...
anyone has a more concrete data about this ?
i m thinking whether to choose a normal 66x or 133x ...
getting 2gb sd card.. either transcend or pretec...
by the way exec sd slot is 1.01 or 1.1 specification?
hope someone has a benchmark to share.. thanks
1gb Scandisk does the job for me.
Watched a movie on it the other night, perfect. Plenty fast enough.
Its HTC so you can be assured it will be genius design with cheap crap chipset.
Bit like an Italian sportscar.
get one of those sd-usb card combo's....if u can find one going at a decent price.
saves the hassle of card readers. the LAST thing anyone needs is yet another wire lol
Guys,
I'm soon going on a trip to the Lake District (UK National Park) and will be doing a lot of climbing/hiking/walking.
Whilst I am at the summits of certain 'Fells' I will be taking photo's with my Digital Camera.
At that point I want to transfer Photo's from the Camera to the Phone and send them directly from the Phone.
Problems I need to overcome:-
The Camera uses SDHC.
The Phone uses MicroSD.
Apart from the Phone there is no power source.
What do you think is the best way to transfer the Photo's to the Phone so that I can then send them over 3G?
Thanks in advance.
Why not use a Micro sd in a Micro SD to SD adaptor, that way you are storing the camera images direct to a micro SD card and can then just put that in your phone to send the images
alanwesty said:
Why not use a Micro sd in a Micro SD to SD adaptor, that way you are storing the camera images direct to a micro SD card and can then just put that in your phone to send the images
Click to expand...
Click to collapse
The camera will not take an adapter.
Don't forget I won't have the option of using a computer.
Why will the camera not take an adaptor I have used these adaptors ina PC and they work just the same as if you had put an ordinary SD card in.
alanwesty said:
Why will the camera not take an adaptor I have used these adaptors ina PC and they work just the same as if you had put an ordinary SD card in.
Click to expand...
Click to collapse
Can you show me which adapter will connect directly to a camera WITHOUT the need for a PC.
Surely you need the PC to transfer the data across?
You can get SD adaptors that are just the same size as an ordinary SD card with a slot in the end to fit a Micro Sd card. This means that they fit anywhere a SD card fits and appear like a SD card to the device they are fitted to. A search on google for "sd adaptor" will find one.
alanwesty said:
You can get SD adaptors that are just the same size as an ordinary SD card with a slot in the end to fit a Micro Sd card. This means that they fit anywhere a SD card fits and appear like a SD card to the device they are fitted to. A search on google for "sd adaptor" will find one.
Click to expand...
Click to collapse
Yes but that would mean taking the photo's DIRECTLY onto the MicroSD Card.
I use high speed burst mode with my camera and that requires a fast SDHC Class 6 16GB Card.
You can not get a 16GB Class 6 MicroSD.
Although some will be released very soon the difference in price is quite high.
I'm trying to overcome having to chop and change cards between camera & Phone.
I am seeking a lead or something on this vein for transferring the data across.
Surely you're going to have to make some kind of sacrafice at some stage, either:
- Shoot on Class 2 MicroSD (via SD Adapter)
- Take laptop/netbook along
- Only other viable option is some kind of device that replicates SD to MicroSD without a PC - I don't think it exists.
You sound like your probably using a DSLR, have you thought about the time it will take to tranfer each photo over 3G, even assuming you can get 3G reception in the Lake District browsing the net on mine can be frustrating enough never mind uploading 4Mb photo's.
Oh and the power issue is pretty big! Have you got a windup/solar charger or a shed load of spare batteries?
Good luck though - it's a worthy cause
foaf said:
Surely you're going to have to make some kind of sacrafice at some stage, either:
- Shoot on Class 2 MicroSD (via SD Adapter)
- Take laptop/netbook along
- Only other viable option is some kind of device that replicates SD to MicroSD without a PC - I don't think it exists.
You sound like your probably using a DSLR, have you thought about the time it will take to tranfer each photo over 3G, even assuming you can get 3G reception in the Lake District browsing the net on mine can be frustrating enough never mind uploading 4Mb photo's.
Oh and the power issue is pretty big! Have you got a windup/solar charger or a shed load of spare batteries?
Good luck though - it's a worthy cause
Click to expand...
Click to collapse
Thanks for the feedback.
Yes, I'm shooting with a couple of cameras (Big Nikon D2Xs & a small semi-pro Panasonic LX3).
The Nikon though uses CFII for storage and I aim to use this camera with it's heavy zoom lens at the foot of the fells.
The LX3 will be going up with me to the top this time as I've done the Nikon before (and what a weight it was).
The last time I had all my gear... Laptop, Mobile 3G, Solar Charger, etc. etc.
This time however I'm trying something different and want to go as light as possible.
I've got the new Proporta portable charger and this will give my Phone plenty of charge.
The LX3 has two spare batteries so that's not going to be an issue.
I did think about using a mobile hard drive like the Archos AV700 (which I have).
It requires no power source using cable alone and has USB Host.
However, it would mean more weight and cables etc.
I just wondered if there were another simple way I could achieve my aim.
I intend to transfer around 3 to 6 pics and appreciate what you say on the speed issue (agree fully) but I want to complete the task which will help in the review I end up writing.
Hi Beards,
I tried but don't have all the right cables to prove it.
I thought the USB on the HD would also behave as a master for storage - so I thought I could connect a USB to a SD converter and that would be the solution. BUT, I don't have a USB female-female connector. I do have a micro USB to USB cable and a USB SD convertor. My aim was to plug it all in and try - Sorry.
Maybe this will work for you with the SD card appearing (hopefully) as storagecard2 but I need the extra cable to prove it.
Only other issue I can think of is the pictures will be big so no MMS transfer will be possible. Only email attachments and then I think there might also be a limit.
Have a great trip !
Cheesy Dave said:
Hi Beards,
I tried but don't have all the right cables to prove it.
I thought the USB on the HD would also behave as a master for storage - so I thought I could connect a USB to a SD converter and that would be the solution. BUT, I don't have a USB female-female connector. I do have a micro USB to USB cable and a USB SD convertor. My aim was to plug it all in and try - Sorry.
Maybe this will work for you with the SD card appearing (hopefully) as storagecard2 but I need the extra cable to prove it.
Only other issue I can think of is the pictures will be big so no MMS transfer will be possible. Only email attachments and then I think there might also be a limit.
Have a great trip !
Click to expand...
Click to collapse
Hi Dave,
Nice speaking with you again.
Thanks for the heads up, this sounds promising.
I've got a couple of weeks to try and sort it out so if you come across anything suitable do please let me know.
Been far too busy in theatre lately. This trip will make a perfect break.
Why not just use the camera's 50mb internal memory to copy from your cheap high speed SDHC card to the micro SD card in SD adaptor combination already suggested? Since you're only talking abut 3 or 4 photos it shouldn't be a great hardship, and you get to shoot the way you like.
shuflie said:
Why not just use the camera's 50mb internal memory to copy from your cheap high speed SDHC card to the micro SD card in SD adaptor combination already suggested? Since you're only talking abut 3 or 4 photos it shouldn't be a great hardship, and you get to shoot the way you like.
Click to expand...
Click to collapse
I'm not taking 3 to 4 shots shuflie.... I'll be 'transferring' 3 to 4 shots to the Phone.
I will be taking around three hundred odd shots in total. I've then got to pick which will then be transferred to the phone.
It's an interesting concept though....
The MicroSD to SD Adapter keeps cropping up in topic here. So on basis this needs to be investigated further.
Edit:
I have just checked the Manual on the LX3 and it would appear this procedure can be done.
According to the Manual I can copy data from an SDHC card to Internal Memory and vice-versa.
So.... all I would need to do is:-
1. Pick from which shots require transferring.
2. Transfer them into Internal Memory.
3. Take out the SDHC Card with all the photos on.
4. Insert the SD Adapter with MicroSD card.
5. Transfer the selected Internal Memory shots on to the MicroSD card.
6. Take out the Adapter and MicroSD card from the camera and remove the MicroSD from the SD Adapter.
7. Insert the MicroSD card into the Phone and temporarily place in internal memory.
8. Take out the MicroSD card and replace with the correct storage MicroSD card.
9. On the Phone, transfer the shots from Internal Memory to the Storage card.
10. Send the shots over 3G.
Phew........ but at least it should work.
DSLR image sending via Touch HD
Hi Beards
I am a news photographer and do exactly this all the time.
There are sacrifices that pretty much have to be made.. you can't do everything you want without power and a laptop / or loads of extra kit.
The sacrifice is basically you cant shoot on class 6 cards you are stuck with the speed of the microSD. However.. we shoot riots, news, entertainment, etc in RAW mode on a Canon DSLR and unless we hammer it and motordrive loads of shots we dont have any problem with the slow microSD cards from SanDisk. I'm not sure what you plan to burst shoot but i would suspect if it serves us ok doing breaking news it should serve you ok up in the countryside. (unless you are doing motorsports or something )
Our workflow is this..
We shoot RAW images on the Canon EOS1D mk II on a SanDiskc 8bg microSD card in a SanDisk SD card adaptor.
We put the microSD card into the touch HD and use an application called Phojo http://www.idruna.com to extract the jpeg image from the raw file and email or FTP the image from our phone. Phojo has a lot of pro features that you may or may not need.. although it is commercial software so may not be something you want to invest in.
Of course shooting JPEG should mean you can shoot even quicker as the files are less than half the size of the raw images and you dont need Phojo to do the extracting of files. You can of course use the touchHD's built in email software then to send them by email if you wish. We recomment Phojo however because it is specifically designed for this application.
There are obviously other solutions.. you can get battery powered tiny USB transfer devices (belkin used to make one) that will transfer the content of one usb device (card reader / card) to another. However we havent had much success with these and they are fiddly.
Your needs match very much what press photographers do every day. All the ones i know do it by using the microSD adaptor / Phojo method (altho most dont shoot RAW they shoot JPEG) The ones who dont use the microSD method are either using a wifi transmitter made by canon or nikon on their camera and Phojo or they are using a PDA/Phone that supports USB host or SD cards.
Hopefully this helps
kind regards
Edward
Equinox Features
http://www.newspics.com
Newspics, that's really interesting. Great to see how the pro's do it.
I feel like there sould be camera's with built in capabilities to upload pics by now. Or at least Bluetooth 3.0 between the phone and the camera. Live Mesh does a pretty good job for me for syncing pics to my PC, if only it could sync between Camera, Phone and PC.
If you will have no access to a power supply how are you going to keep your phone charged?
I picked up a gtab and want to use it while on vacation or backup the photos from my SLR's compactflash memory cards to a portable hard drive. Is this possible?
Basically it would be the usb adapter, then USB hub, with a compactflash (or SD) memory card reader and usb hdd off of it.
Anyone who has tried this, can you comment on the speed of transfer? The RAW images are around 30mb each and I have a 16gb and 2x 8gb memory cards.
Here's my method... I have a Canon 40D.
1. Like it or not the world revolves around SD, not Compact Flash. So, don't use Compact Flash, use SD memory. Buy an adapter here and then you need only ever use SD cards going forward.
2. You can load your photos onto your TAB using Samsung's USB adapter for the TAB. Plug in an USB based SD card reader into the TAB and suck all the pictures off the SD card.
3. Get a Microsoft Live account. It's free. Along with the Microsoft Live account you get a free 25GB "Sky Drive" to store whatever you want.
4. Go to the marketplace and search for Sky Drive. There are a couple of apps there that will let you move files from your tab to the Sky Drive.
If you need more than 25GB of space then you can do this to free up space on the Sky Drive...
1. Put Microsoft Live on one of the computers in your home.
2. Put the free version of Logmein on your home PC.
3. Buy and install Logmein Ignition for the Tab.
4. Log into your home computer from the Tab via Logmein and move the files from the Sky Drive to your home PC.
You might be able to create a script to move the files from Sky Drive to the PC automatically, thus saving you the purchase of Logmein Ignition.
I am a Pro, and I wish the Pro world revolved around SD, but current generation Nikons are all CF.
Having said that, I have read some people being able to mount portable HDDs with rooted Transformer and Iconia and have access to the full capacity of the drive. But, they also have a full USB port built in.
The Market App is: https://market.android.com/details?id=au.dach.drivemount
TabGuy said:
1. Like it or not the world revolves around SD, not Compact Flash. So, don't use Compact Flash
Click to expand...
Click to collapse
I stopped reading after this. ALL Pro bodies use compact flash. They have higher capacities, and are more resilient to damage than SD. This will never change. Anyone saying SD is better than CF doesn't know their Aperture size from their shutter speed.
evanrich said:
I stopped reading after this. ALL Pro bodies use compact flash. They have higher capacities, and are more resilient to damage than SD. This will never change. Anyone saying SD is better than CF doesn't know their Aperture size from their shutter speed.
Click to expand...
Click to collapse
You are correct, I'm not a pro photographer. However, I've shot over 40,000 photos on my 40D ALL on SD without ever a single SD failure. I'd say that's a pretty good track record.
The world does revolve around SD. It's the vast majority and the most compatible. It rules the market the way Windows rules the PC operating systems.
Is it better? I don't know. I didn't say one way or the other. To paraphrase your post: A person that thinks I said that SD was better than Compact Flash doesn't know their verbs from their nouns.
It's simply more convenient, cheaper, and in almost all cases just as safe. Maybe, back in the early days of SD it was prone to more failure but living in the past is no way to be successful in the future.
For the time being I can't move away from compactflash. When I get a new camera in a few years, I'll see what camera floats my boat then. Please keep this on compactflash since that's what I have now Although, I do appreciate the suggestions. I am not a "pro" photographer (actually an engineer). But, it is one of my favorite hobbies.
When I travel to other countries, I usually either don't have access to wifi or I don't have access to fast enough wifi to upload the pictures to a cloud drive. I really need to be able to plug in the card reader AND the hdd at once (since the gtab doesn't have enough internal space for my pic backups). I haven't seen anyone post in the forums yet that they confirmed you can access 2 drives (reader and hdd) simultaneously to copy between then
If I can find a usb adapter at best buy and a powered hub I'll try it. Supposed I can take them back if it doesn't work. Just hoping someone already tried it and could tell me which hub/cardreader/etc to get to save some hassle of swapping out a few hubs/card readers.
TabGuy said:
You are correct, I'm not a pro photographer. However, I've shot over 40,000 photos on my 40D ALL on SD without ever a single SD failure. I'd say that's a pretty good track record.
The world does revolve around SD. It's the vast majority and the most compatible. It rules the market the way Windows rules the PC operating systems.
Is it better? I don't know. I didn't say one way or the other. To paraphrase your post: A person that thinks I said that SD was better than Compact Flash doesn't know their verbs from their nouns.
It's simply more convenient, cheaper, and in almost all cases just as safe. Maybe, back in the early days of SD it was prone to more failure but living in the past is no way to be successful in the future.
Click to expand...
Click to collapse
I wasn't implying SD cards would fail, as I have an SD card in my pocket camera I use when I don't want to take a Large Body/Lens set with me. I wasn't necessarily implying that SD cards fail, more that due to their thinness, they could snap, warp, etc. Also, as CF cards have a much more rigid body, they're more resilient in a disaster case. Ever tossed a memory card through the washer/Dryer? Run over it with a car? CF cards can stand a lot of abuse.
The one nice feature of SD cards that I wish CF cards had is the write protect switch. I have a memory card holder for my CF cards that has colored tabs you can use to tell if they're full or not, but a Write protect switch would be kinda nice.
A few years ago, SD cards were extremely expensive, compared to CF for GB to GB comparison. Today, the price gap is much much narrower, in some cases SD is cheaper than CF (although usually slower in terms of read/write speeds)
Both formats have their place. I don't discount SD, nor do i imply you're wrong in any way for using them, as I have a number of devices that use them, but CF also has it's place, in the professional world where photographers require the utmost performance and reliability from their memory devices.
On a side note, my company produces industrialized standalone computers that are remotely deployed on telephone and light poles in Pakistan to collect RFID tags on shipments bound for Afghanistan. These devices run solely on CF cards as well due to their durability.
adamjt said:
I picked up a gtab and want to use it while on vacation or backup the photos from my SLR's compactflash memory cards to a portable hard drive. Is this possible?
Basically it would be the usb adapter, then USB hub, with a compactflash (or SD) memory card reader and usb hdd off of it.
Anyone who has tried this, can you comment on the speed of transfer? The RAW images are around 30mb each and I have a 16gb and 2x 8gb memory cards.
Click to expand...
Click to collapse
30MB! You must have 5DII, 1DMKx or D3X? Anywho, like mentioned, the best bet would try a usb hub
adamjt said:
I picked up a gtab and want to use it while on vacation or backup the photos from my SLR's compactflash memory cards to a portable hard drive. Is this possible?
Basically it would be the usb adapter, then USB hub, with a compactflash (or SD) memory card reader and usb hdd off of it.
Anyone who has tried this, can you comment on the speed of transfer? The RAW images are around 30mb each and I have a 16gb and 2x 8gb memory cards.
Click to expand...
Click to collapse
You'd have probably been better off buying one of those portable image transfer drives...they're made for this exact purpose. Take a memory card, plug it in, hit copy. They're only like 100-150 or so, much cheaper than a tablet.
http://www.amazon.com/Nikon-MSV-01-Coolwalker-Digital-Storage/dp/B0006283AG
http://www.digitalfoci.com/media_buddy_selection.html
http://www.amazon.com/PicPac-Memory-Reader-Storage-7632/dp/B003QP49NA/ref=dp_cp_ob_p_title_2
i bought this new card and was happy that i have a fast card now and that the transferring data with usb connection would be faster, but it is not.
The writing speed is between 3-5 MB/s, not better then my old Sandisk 16gb class2 card.
I have aMAGLDR v1.13 with CWM v.5.0.2.7.
I use the usb mount from CWM and transfer data through it, but it is really a disappointment. I format the card through different ways, all without any success.
On the my computer the card is not faster with FAT32 (with the micro sd adapter), when i format the card to NTFS it is really fast, but i can not use it on my phone with NTFS. Is Fat32 the problem here?
Does someone have the same card and could approve this problems or am i the only one?
thanks in advance /masteroe
try this..
get into android and see if this app works...it will increase the cache...you should see difference..
thanks, i tried this already without any success.
it seems that the problem is not this value. In the CWM this value is not interesting at all.
As i told you on Windows i have same performance issues with FAT32....
If you bought your SD card from Ebay you probably bought a fake Class 10
domimatik said:
If you bought your SD card from Ebay you probably bought a fake Class 10
Click to expand...
Click to collapse
it is not from the bay it is a original card (i hope) from amazon.
Class 10 only assures you of 10MB/S on sequential write, so if the card has been written to a few times there could be some drop due to fragmentation. Also, there are various overheads to consider, moving the data about, issuing the write command to each block, wait for a confirmed write response, blahblah.
Here
http://www.smxrtos.com/articles/whiteppr/flashperformance.htm
Is a (very) technical explanation, which rather happily (or not) examines a 10MB/S raw write speed SD as an example (scroll way down) and calculates an actual write speed at 5MB/S.
samsamuel said:
Class 10 only assures you of 10MB/S on sequential write, so if the card has been written to a few times there could be some drop due to fragmentation. Also, there are various overheads to consider, moving the data about, issuing the write command to each block, wait for a confirmed write response, blahblah.
Here
http://www.smxrtos.com/articles/whiteppr/flashperformance.htm
Is a (very) technical explanation, which rather happily (or not) examines a 10MB/S raw write speed SD as an example (scroll way down) and calculates an actual write speed at 5MB/S.
Click to expand...
Click to collapse
thanks for your information, but i think there is an other problem, my class 2 card is faster as it seems . I'm copying 700 MB with 1,5MB at the moment, that is really frustrating....
hehe yea i know what you mean, mine always runs far slower than it probably should too, one point some meg/s, for both my class 2 and a class 6, never any faster, either through cwm, android usb mass storage, or my card reader. (Lots of built in card readers are just usb readers mounted to internal usb headers, and are often only usb1, which doesn't help, , usb has a lot of overhead, lots of info regarding usb overhead here http://www.smxrtos.com/articles/usb_art/usbperf.htm (if a little old))
i will give back the card. This card does not make sense with HTC HD2..
Thread can be closed ! Thanks anyway ..
Hello All,
I know there are lots of threads here about which SD cards work with the Defy, and which don't... E.g.:
[/showthread.php?t=1159877]
[/showthread.php?t=1660621]
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However, as an experienced computer hardware tech, it all seems very back-to-front to me. When you buy a new PC motherboard, the manual invariably tells you what memory type it requires, what speeds it can handle, and what its maximum memory data transfer rate is. Then, you can simply go out and buy the fastest memory the motherboard supports, and be fairly sure of two things: 1: it's going to work, and 2: you'll have the fastest memory speed you can get out of the motherboard, without wasting money buying faster memory than it can utilise.
For those who don't really understand these things, every motherboard, every CPU, every memory controller and every memory module has a maximum rated speed [over-clocking not included!] at which it is 'guaranteed' to work and be reliable. If your motherboard/CPU/memory controller has a maximum rated 800MHz memory transfer rate, there is no point installing 1333Mhz memory in that motherboard, because the motherboard will only run it at 800MHz. You'll pay more, for no speed or reliability advantage. In fact, as this forum shows, there is a VERY GOOD chance that you'll end up with something that is less reliable. This is because, as chip speeds increase, of necessity, certain timings and timing relationships change. For example, "Data Hold" times may [probably will] decrease, meaning that when reading data back from a faster memory chip, the data is starting to "disappear" from the output pin, before the CPU has had time to properly read it. The data transfer becomes "marginal", meaning it only just works, or doesn't quite. This will result in memory read errors (which will look like data corruption, even though the data inside the chip is perfectly correct), and will result in many of the problems described in these various threads. It will probably vary, depending on temperature, supply voltage, and type of data transfer (e.g. Photo/Video/USB, etc) and even phone - I.e. One Defy might work, the next might not - or your system (PC, phone, etc) may work for some things but not others, or work when it's cool, but bomb out as it gets hot, or vice versa. Instability and Unreliability are the keywords!
This, I submit, is why many people with Class 10 SD cards report problems. They would, I believe, be far better to buy Class 6, and are probably living under the illusion that a Class 10 card will work faster. I would say, it almost certainly won't...
Anyway, my point is, why do phone makers (or Motorola at least as I haven't really looked at other manufacturers) not publish their phone SD Card slot specifications? I just don't understand why not. It seems so fundamental to me.
If they did, you (everyone) would know what card Class to get, and be confident that it should work, and that if it doesn't, you've got a dodgy card. We wouldn't need long threads on XDA Developers discussing which cards work, and which don't.
So, my Defy came (OEM) with an unbranded 2GB micro SDHC card, with no visible Class mark. I wanted to upgrade, so I searched the Motorola Manuals for the SD Card slot spec, to find out what Class I needed. AMAZING, but No Luck! I couldn't find it anywhere.
So I looked at a cellphone accessory suppliers website, to see what they offered.
Url [not allowed]
Nearly all cards listed for the Defy are Class 4, so I figured the Defy must have a Class 4 slot.
I bought a 32GB Class 4 ADATA micro SDHC card, locally. It worked, no problems. I have tested it fairly thoroughly, copied a couple of GB of data to it (over USB) and done a bitwise comparison of the data. No problems. I have taken and viewed photos and movies, and seen no problems. I also tested the memory speed (using SD Tools from Google Play). It gives Write speeds of around 6MB/s and Read around 15MB/s.
However, while I was there, I spied a clearance priced 4GB Class 6 card, so bought that too. (Also ADATA.) Haven't tested that so much, but did run the same speed test in the same Defy phone. Was disappointed to find that the Write Speed is over 9MB/s (though Read is still around 14-15MB/s.)
From this, I conclude that the correct speed Class for the Motorola Defy SD card slot is actually Class 6 (and that I should have bought a Class 6 card... )
Can anyone tell me whether this is correct, and where, if anywhere, the actual manufacturer's SD card slot spec's are published?
BTW, the original 2GB card looks, from SD Tools, to be a Class 4 card, though oddly, the speed seems to vary a lot with that card. It sometimes, at the start of the test, goes as high as 10MB/s, but usually stabilises and ends at about 5.6MB/s (Write speed).
Also, can anyone with a Class 10 card (that works) in their (Original model) Motorola Defy please report here what data Write and Read speeds SD Tools reports? I think everyone with a Defy who wants to upgrade their memory would be very interested to know!
I think it would be great to finally nail this issue down.
Regards,
D2