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SanDisk SDSDB-512-768 512 MB Secure Digital Card

SanDisk SDSDB-512-768 512 MB Secure Digital Card

List Price: $249.99
Your Price: $53.84
Product Info Reviews

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Rating: 5 stars
Summary: Why so much cheaper?
Review: This card works perfectly in my Treo 600 and Viking 6-in-1 drive. (For other Treo 600 owners who may be wondering, in light of the warning card included with the Treo, the SanDisk card IS compatible.) I haven't had a single problem.

Rating: 2 stars
Summary: Value depends on how much data you move & how often
Review: This review applies to computers equipped with usb2.0. Users who have usb1.x may still find this informative, however.

I just received a SanDisk 512MB Ultra II Secure Digital card and did a quick & dirty performance comparison with the non-ultra SanDisk SD card. If you just want the results, then go to the bottom of the review. For the more inquisitive, here is my test configuration:

linux-2.4.22 (with ehci to enable usb2.0) connected to . . .
usb2.0 hub connected to . . .
SanDisk SDDR-88 usb2.0 memory card reader

commands for the write test:
- mount -o noatime,sync /dev/sda1 /flash_memory
- cat testfile > /dev/null
- time cp tesfile /flash_memory

The first command forces any writes to the flash_memory to happen immediately, so there is no caching going on. The second command reads through the ~50MB testfile and caches it into memory (no need to access the hard disk). The third command actually copies the test file to the memory card and times it.

commands for the read test:
- umount /flash_memory
- mount -o noatime,sync /dev/sda1 /flash_memory
- time cp /flash_memory/testfile /dev/null

The first command unmounts the flash memory and clears the cache. The second command mounts the flash memory so the computer can access its files. The third command actually copies the file, which must be read directly from the card because we cleared the cache, and times the copy.

The read and writes tests were performed multiple times, and the results varied little between iterations. The 512MB card was completely empty, and the 256MB card had a small 3MB file.

The SanDisk Ultra II card turned in some impressive numbers:

writes: 4.95MB/sec (5048.2KB/sec)
reads: 8.19MB/sec (8389.96KB/sec)

For comparison, here are the numbers for the SanDisk 256MB non-ultra card:

writes: 0.86MB/sec (876.44KB/sec)
reads: 1.53MB/sec (1570.69KB/sec)

If you need performance, then the SanDisk Ultra II series + usb2.0 is a winning combination. The Ultra II reads and writes more than five times as fast as the plain-vanilla SanDisk secure digital card. In my case, I will be using the card to store MP3 files for a portable audio device, and waiting around while moving MP3s is not how I want to spend my time. So, I bought the Ultra II. Your needs may vary. Buy accordingly.

Compare prices between the Ultra II and non-Ultra cards and ask yourself, "How much is my time worth?" If you answer this question honestly, then you won't be kicking yourself later on because you bought the wrong card. For people who copy small files frequently, the non-ultra cards provide great value for the dollar. If you move larger files, however, then have something else to do during the copy operation because the non-ultra cards will frustrate you otherwise.

Also, I realize that other manufactures market "high-performance" memory cards, but since I don't own one, I can't recommend/jeer them here.

Rating: 2 stars
Summary: Value depends on how much data you move & how often
Review: This review applies to computers equipped with usb2.0. Users who have usb1.x may still find this informative, however.

I just received a SanDisk 512MB Ultra II Secure Digital card and did a quick & dirty performance comparison with the non-ultra SanDisk SD card. If you just want the results, then go to the bottom of the review. For the more inquisitive, here is my test configuration:

linux-2.4.22 (with ehci to enable usb2.0) connected to . . .
usb2.0 hub connected to . . .
SanDisk SDDR-88 usb2.0 memory card reader

commands for the write test:
- mount -o noatime,sync /dev/sda1 /flash_memory
- cat testfile > /dev/null
- time cp tesfile /flash_memory

The first command forces any writes to the flash_memory to happen immediately, so there is no caching going on. The second command reads through the ~50MB testfile and caches it into memory (no need to access the hard disk). The third command actually copies the test file to the memory card and times it.

commands for the read test:
- umount /flash_memory
- mount -o noatime,sync /dev/sda1 /flash_memory
- time cp /flash_memory/testfile /dev/null

The first command unmounts the flash memory and clears the cache. The second command mounts the flash memory so the computer can access its files. The third command actually copies the file, which must be read directly from the card because we cleared the cache, and times the copy.

The read and writes tests were performed multiple times, and the results varied little between iterations. The 512MB card was completely empty, and the 256MB card had a small 3MB file.

The SanDisk Ultra II card turned in some impressive numbers:

writes: 4.95MB/sec (5048.2KB/sec)
reads: 8.19MB/sec (8389.96KB/sec)

For comparison, here are the numbers for the SanDisk 256MB non-ultra card:

writes: 0.86MB/sec (876.44KB/sec)
reads: 1.53MB/sec (1570.69KB/sec)

If you need performance, then the SanDisk Ultra II series + usb2.0 is a winning combination. The Ultra II reads and writes more than five times as fast as the plain-vanilla SanDisk secure digital card. In my case, I will be using the card to store MP3 files for a portable audio device, and waiting around while moving MP3s is not how I want to spend my time. So, I bought the Ultra II. Your needs may vary. Buy accordingly.

Compare prices between the Ultra II and non-Ultra cards and ask yourself, "How much is my time worth?" If you answer this question honestly, then you won't be kicking yourself later on because you bought the wrong card. For people who copy small files frequently, the non-ultra cards provide great value for the dollar. If you move larger files, however, then have something else to do during the copy operation because the non-ultra cards will frustrate you otherwise.

Also, I realize that other manufactures market "high-performance" memory cards, but since I don't own one, I can't recommend/jeer them here.

Rating: 4 stars
Summary: 483mb?
Review: When I got it, I put it in my IPAQ 5555 PDA. It shows only 483mb not 512mb. I know it shouldn't be exactly 512mb, but almost 30 mb different is not too much?

Rating: 5 stars
Summary: Fast and flawless at the right price.
Review: Works just fine in my Minolta G500 camera. Can't imagine what there could be to criticize. Can't beat the price either.

Rating: 4 stars
Summary: Speed Test Results...
Review: [Note: This review was originally posted on 20-Oct-2003 and contains an important update made on 29-Oct-2003! Be sure to read the entire review for details!]

SanDisk's 512MB SD card is by far the cheapest available. In most cases, the other cards are at least 50% more than this one.

I was curious about speed since SanDisk is known for being a bit on the slow side. This card was relatively newly released when I wanted it, so I was unable to find any good speed figures online. Therefore, I bought it anyway -- and ran the speed tests myself.

Testing on a Toshiba/AudioVox Genio e550G with Kai's Speed Test application, I ran the Write Test 5 times with the following results:
Trial #1: 263KB/Sec
Trial #2: 263KB/Sec
Trial #3: 181KB/Sec
Trial #4: 171KB/Sec
Trial #5: 196KB/Sec

Not very consistent, for some reason. I was not running any other applications at the time, so I am not sure why the fluctuation.

For comparison, here are the results using a Lexar 256MB SD card:
Trial #1: 263KB/Sec
Trial #2: 271KB/Sec
Trial #3: 279KB/Sec
Trial #4: 256KB/Sec
Trial #5: 256KB/Sec

So, at their best, the two cards seem quite comparable. It is just that the Lexar card is clearly more stable as far as speed fluctuations go.

In any case, I'm happy with it -- especially for the huge difference in price in most cases. Works for me. Plus, 5-year warranty -- just in case.

- John...

---UPDATE---
The fact that the card always performed well for the first two tests but then slowed and stayed slow until the device was reset was really bothering me, so I contacted SanDisk about it and gave them the same results that I shared here. SanDisk said that they thought the card was defective! I therefore had this card replaced (very quickly and easily by Amazon, I will add) and have just repeated my tests with the new card. Good news! The replacement card is usually faster and much more consistent than the original! It no longer slows down after the first two tests -- the results are repeatable at any time.

For comparison, here are the new figures for the 512MB SanDisk card:
Trial #1: 329KB/Sec
Trial #2: 263KB/Sec
Trial #3: 341KB/Sec
Trial #4: 279KB/Sec
Trial #5: 318KB/Sec

As you can see, the card is now performing at or above the speed of the 256MB Lexar that I had previously tested. I am now quite satisfied with this card -- it appears to be giving the same speeds or better than other cards well above this price range.

- John...


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