I was playing to set a Windows 8 system up to use a 32 GB SSD as a system cache using the Intel Smart Response Technology, where you enable acceleration from within the Intel Rapid Storage Technology utility. It seems transfer rates on files being transferred internally dropped significantly. This includes external USB 3.0 devices where the transfer rate dropped from the 80-125 MB/s rate to 14 MB/s. Turning off acceleration, even part way through a large file transfer, allowed the rate to recover immediately. If anyone has any experience or explanation for this, please advise. I did use the Intel Rapid Storage drivers from ASUS and the latest one from Intel with the same results. Thanks Edit: It turns out the problem was the SSD I was using. Even though it was a SATA III, the sequential write speed was fairly slow. Replacing the drive with an Intel 520 SSD resolved the issue.