hard disk <> memory card transfer speeds.

I just transfered files (photos) from a sandisk 8gb extreme IV compact flash card to a hard disk array in raid0 (two 500 GB SATA UDMA 7200rpm drives)

the cf card’s quoted transfer speed is up to 40mb/s the quoted transfer speed for ONE of the above type HD is 300mb/s yet my transfer maxed at 6.5mb/s!!

This is in windows vista (x64) on a quad core cpu with 4gb of ram, so it’s not as if resources were being strained.

Is 6.5mb/s normal in the above situation???

The listed transfer rates are the theoretical maximum, and are pretty much always obtained by reading or writing large, contiguous files. In practice, they are rarely, if ever, reached for a significant length of time. Your transfer rate is about normal for a USB card reader.

I just did the same transfer but off the hd and onto an external hd… this was 15mb/s

This is raid0 magnetic to ordinary magnetic over USB how can this be faster than solid state to raid0 magnetic?

edit: sorry, didn’t see your reply there (and now I can’t see what your name is because post edit doesn’t show previous posts :smiley: )

I get about 12 Mb/s on Linux, with a large enough disk cache that the HD speed is probably unimportant. This is with a cheap USB 2 flash reader over a cheap external USB 2.0 hub. I used to use a USB 1 reader and it was much slower.

My first guess would be that your card reader is the determining factor.

The main bottleneck is the USB port and card reader. USB isn’t known for very high speed. If you took the drive out of the external HD and put it inside the computer, it would be a lot faster.

Also, you’re comparing apples and oranges. First, hard drives have internal buffers that increase throughput. Second, you wrote data to the hard disk, but read data from the card. Third, the chipset in the card reader is not the same as the one in the external drive’s USB interface, with the card reader’s chipset being slower.

If all of this is unacceptable, you can get a CF to SATA adapter that will be faster than USB.