The default sd cache size on the Hydro is (as far as I remember) 128 KByte.
If you increase the cache the speeds will get a bit better.
You can increase it either manually or download a free or paid app.
I am lame and use an app (SD-Booster), because the size limit is embedded in the kernel and will resize (default / aka shrink down to 128 Kbyte) after a reboot.
I have tried 1024 Kbyte cache and 2048 Kbyte cache, and for me 1024 works best, but you might also want to try what ever you feel like it.
Before you enable "set at boot" you should make sure that you're phone is stable. I heard if it is set too large the phone might become unstable, but I have never tried anything more the 2048 Kbyte anyway.