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Old Mar 25, 2007, 7:13 PM   #1
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hi everyone

i have recently purchased a sandisk 2gb extreme sd card from picstop.co.uk for my nikon d80, which i will pick up on the 2nd april, and require some advice on its claimed speed of 20mb/sec 133x.

i am weary of fake sd cards in the market and specially shopped from picstop as they were from listed retailers on sandisk website. the card does not seem fake, everything from packaging to the card seems perfect, i have even checked with sandisk the serial number of the card which is ok however i am bit concerned with the speed of the card. to be honest i am a bit confused so please bear with me. To check the speed of the card i used SiSoftware Sandra flash memory benchmark, the results i received are as followed:

combined index: 1588 operations/min
512b file test combined: 2112 operations/sec
32kb file test combined:1671 operations/sec
256kb file test combined: 710 operations/sec
2mb file test combined: 140 operations/sec

also from my own calculations by transfering certain files i worked out 2mb/sec. from these results, does the claimed 20mb/sec match? On Sandra its possible to compare results with other flash drives and the extreme iii to me seems pants for its claim, think its me so please correct me. forinstance compared to a "kingston SD" which performs the combined index by 4068 operations/sec.

i am confused and look forward to any help, thanks in advance.
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Old Mar 25, 2007, 8:19 PM   #2
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It would seem that real world testing doesn't verify SanDisk's claims...which, if I read this correctly, states a min (minimum?) of 20MB/sec sequential read and write.

http://www.sandisk.com/Products/Item(1973)-SDSDX3-2048-SanDisk_Extreme_III_SD_2GB.aspx

Uploading to a computer with a card reader, the 1 GB Extreme III (they didn't test the 2 GB card here) barely broke 17MB/sec...

http://www.robgalbraith.com/bins/no_...?cid=6007-8472

With a D80, the 2 GB Extreme III wrote at 9.414MB/sec.

http://www.robgalbraith.com/bins/mul...?cid=6007-8531

Maybe I don't understand what sequential read and write means. At any rate, 2 MB/sec seems way too slow. I don't know how to correlate your posted test results with MB/sec. Are you sure you calculated correctly?

the Hun


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Old Mar 25, 2007, 8:42 PM   #3
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thanks for the reply Hun

just done some quicktest. basicaly took 360mb of jpeg data from my computer and dumped it into the card, which took 126seconds that would mean 360/126=2.8. therefore 2.8mb/sec (hope this is correct). then took the same amount of data and dumped it on to desktop, which took 25secs= 14.4mb/sec. i know Sandra's readings are hard to work out, but hopethe calculationsi have just done are correct. even then, its still off the claimed 20mb/sec.
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Old Mar 25, 2007, 10:49 PM   #4
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There is no mutually agreed upon standard way of testing the throughput of flash memory, so under the circumstances that SanDisk tests their cards, they might get the 20MB/sec. they quote. Plus, when you copy files from one location to another, there are lots of other things that happen that don't necessarily show up in your benchmarks (ie.: reading the file allocation table to locate free space to write a new file segment to, verifying the file was written correctly, adding an entry in the file allocation table for the new file, etc.) Also, there are numerous components between your hard disk and the flash memory card that could be a bottleneck, such as other processes that might be running, USB negotiation, USB chipset throughput (in the card reader, the camera and in your computer.

Benchmarks like SiSoftware Sandra should only be used to compare different devices when only one component of the system has changed. You shouldn't expect your test results to match other published benchmark results, unless your system matches the system used in the benchmark.

BTW, before you run benchmark tests like these, you should format the card. That lays down a fresh file allocation table. Otherwise, the computer might take a while locating free space that will accomodate the file you're trying to write to it.
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Old May 21, 2007, 1:19 PM   #5
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TCav
Would you give a hint to what card would be best in that the SDHC requires a Fat 32 format via Windows....
I have a Mac, an FZ20 and L1 plus a Panasonic disgcam
Just worked out that way, honest.. not just a Pany fan, hek I have the Pioneer Elite Plasma... hmmm, now that I think of it my other TV is made by Mashushita

Oh dang.. I am

Seriously. I wonder if a hobby guy needs the SDHC hassle and would be better off with say 2 SD Ultra II 1 gig cards
I use them now in the cameras so all can be interchanged. Makes sense that way and wont have to get a new reader either
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Old May 21, 2007, 6:19 PM   #6
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Always, ALWAYS, ALWAYS the best place to format you cards is in the camera.

And if you really need to, the Mac can format with FAT32.

And while my camera supports flash memory cards larger than 4GB, I don't own one. When you consider the cost/megabyte, the cheapest cards are the 2GB and 4GB cards anyway.

And I've never been a big fan of putting all my eggs in one basket, anyway.
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Old May 21, 2007, 6:57 PM   #7
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Thanks
Just got a notice from Amazon that a 4 ig Sand Disk SDHC with the Micromate reader just got shipped. I had it in the cart and left it thinking I would just wait for an answer, then decided to go for the regular 2
Oh well.... LOL
My fault

http://panasonic.jp/support/global/c...formatter.html


I did however see that Panasonic on their website said it had to be formatted via PC using their software . Maybe just their card? I will have to see. Pany and SD developed this together so I just assumed.
Here is the deal.. the card reader is about $20 by itself, no shipping and no taxes so it seems to be a good deal
Amazon.com items (Sold by Amazon.com, LLC):
1 SanDisk SDHC Memory Card B... $52.95
SanDisk SDHC Memory Card Bonus MicroMate Reader 4.0 GB SDSDBR-4096-A10

So I guess I have this issue solved for the moment

Thanks again
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Old May 21, 2007, 7:25 PM   #8
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tommccarty wrote:
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I did however see that Panasonic on their website said it had to be formatted via PC using their software.
Got a nearby friend that won't mind you installing software on his PC?
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Old May 21, 2007, 7:32 PM   #9
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well yeas and no. I have a Mac G5 dual processor and I can run Windows 2000 or XP Pro on it using VPC
All I need to do is put the software on a disk and insert to windows.. then run it
I do that with the Garmin GPS. I just hope once it is formatted I can down load to adobe via the usb 2 reader into the mac.

If not, I will bet the next camera I get will also need this card
Speed rating is two, now I see 44 on some.. wow
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Old May 22, 2007, 6:34 AM   #10
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tommccarty wrote:
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I have a Mac G5 dual processor and I can run Windows 2000 or XP Pro on it using VPC
All I need to do is put the software on a disk and insert to windows.. then run it
I do that with the Garmin GPS.
Good luck with that. Formatting utilities can be timing dependant, and they may not work when running an OS inside another OS. And if you're running OSX, you'd be running an OS inside another OS inside another OS.
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