|
423 of 432 people found the following review helpful:
4.0 out of 5 stars
Performance is worth the price premium., February 10, 2004
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.
|