SD Card - Optimize for Performance?

Question

I'm running XP Pro with SP3.

For USB memory sticks, I can right click, Properties -> Hardware -> Policies and select 'Optimize for Performance' or Optimize for Quick Removal'.

I also get these options for SD cards in my build in reader, but every time I set these to 'Performance', this is reset after a reboot.

The performance of the SD card is not too bad, but when I try to copy folders or directory trees with large numbers of files, it's so slow. Even if the files are very small, it's still really slow. I don't think it's the card, it's a brand new Transcend Class 6 card.

Any of you guys got any idea why?

Answer 1

The setting you mention doesn't actually affect the real transfer speed.

When you choose "Optimize for quick removal" Windows simply transfers the files to the SD card as though it's just another drive, it doesn't cache anything or do anything fancy. The speed that's reported is the true speed that the card can handle.

When you choose "Optimize for Performance" Windows reads the file into memory, and in the background, transfers the file to the drive. The effect of this is that Windows claims the file is transferring faster, but the file isn't actually on the SD card when Windows claims the transfer is done. The only thing that's actually done is reading the file into memory. If you try to safely eject your SD card while there's still a background transfer, Window will make you wait until it's actually complete.

In general, SD cards and USB sticks are fairly slow. Your hard drive will be much faster, so this option makes it look like SD cards and USB sticks are just as fast, but it's just a dirty background trick, the actual transfer speed is still slow.