421 of 427 people found the following review helpful:
4.0 out of 5 stars
Performance is worth the price premium., February 10, 2004
This review is from: Sandisk 512 MB Secure Digital Ultra II (SDSDH-512-901, Retail Package) (Personal Computers)
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 is the way to go. 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.
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.
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123 of 124 people found the following review helpful:
5.0 out of 5 stars
Big. Fast., September 19, 2004
This review is from: Sandisk 512 MB Secure Digital Ultra II (SDSDH-512-901, Retail Package) (Personal Computers)
BIG. If you have a 3 megapixel camera or higher, then this SD card is for you. You should take all your pictures at the highest resolution and the least compression as possible. For 3 mp cameras, each picture will be about 1 MB to 1.5 MB (more than 300 pictures in this card). For 4 mp cameras, each picture will be about 2 MB (about 250 pictures in this card). This card will allow you take a LOT of pictures before you'll have to unload to your computer.
FAST. This card not only carries a lot of storage space, this is also fast. Even if the card is full, you will be able to download all your pictures to your computer in under a minute instead of several minutes on a regular card.
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47 of 49 people found the following review helpful:
4.0 out of 5 stars
Performance and price - think twice, December 9, 2005
This review is from: Sandisk 512 MB Secure Digital Ultra II (SDSDH-512-901, Retail Package) (Personal Computers)
There's a review here where someone takes their COMPUTER and analyzes the performance of the card. Unfortunately, most of the time what matters is how the card works with your CAMERA. A camera generally doesn't move data as fast as a computer, and it has to process it first - so those tests really only measure how fast you can download the images (or other files) to your hard drive. If that matters to you, great.
For the rest of you, especially camera users, here's the real story:
- You need a faster than standard card if you plan to use 30fps 640x480 video. It's also a good idea with high resolution cameras, if they are especially fast at processing and writing the images.
- But ... I just bought a different 512MB SD card for $10 after rebate. It's hard to beat that price / performance ratio if you're just storing photographs. Sure, video of the 2 year old nephews is fun a couple times a year, but other than that, regular speed cards work fine for many uses.
Always buy what's right for your needs. And, if the price differences are small, go with the faster card.
There are promotions every week on various memory cards, look for one if you have time. Those can make higher speed cards a good value, though the standard speed cards have gotten so inexpensive you may want one as a backup as well.
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