I had been testing my 3.0 transfer speeds when I decided to try the Smart Response Technology using a 32 GB SSD. After I had enabled Acceleration and things looked normal, I noticed my USB 3.0 transfer speeds had dropped to USB 2.0 transfer speeds. Namely, copying a file, to an external 3.0 device changed a 125 MB/s speed to 14 MB/s. Even disabling Acceleration would only allow the speed to go to 75 MB/s and never returned to the original 125 MB/s. Speeds would only drop off from the initial speed after the first 5 or 6 GB of data transfer, or first few seconds.
It should be noted, that during my testing, a transfer between 2 external USB 3.0 devices remained at 125 MB/s and stayed constant during the entire transfer of both a 12 GB and 16 GB file/s. So the title of the thread may be misleading, but it should fulfill my intent.
Specifics:
Motherboard ASUS P8Z77-v Pro
Processor: i7 3770K
Memory: 16 GB
I noticed the problem on my normal Windows 8 system. So I decided to do a fresh install and load the drivers in stages. The first test was with no extra drivers, The Second was with the Intel Rapid Storage Technology driver for Windows 8 from ASUS. And the third was with Acceleration enabled using the 32 GB SSD. I will try an Intel driver for a Z77 motherboard later, but have not yet done so.
The first two tests showed a good speed for the USB 3.0 to internal file transfer. The speeds were a little better and more stable with the Intel driver installed.
After Acceleration was enabled, a transfer that would run a 230 MB/s for the first few seconds and then drop to 125 MB/s, now started at 125 MB/s and dropped to 14 MB/s. Same file and same transfer process.
I also noted Internal transfers to same the hard drive, on different partitions, or internal hard drives on different controllers also showed speed problems.
So my conclusion is the Intel SRT severely limits transfer speeds between external USB 3.0 to internal, or internal to internal drives. The title was chosen to alert folks thinking they have USB 3.0 driver problems, may actually have something else. I know many of the HP computers have mSATA drives which may be involved with this same process.
If anyone can recommend testing in a different manner, please advise.