Intel SSD eSATA speed drop (from SATA3 to SATA2) by RST
Hi, I'm using intel SSD 730 480GB(AHCI mode), Asrock Z97 extreme 6 motherboard, Win 8.1 x64 (genuine)
When I use intel SSD as a external drive thru e-SATA 6g(via SATA-eSATA bracket), there's strange thing happend.
At first, it transfers data using SATA3 bandwidth, 480MB/s.
However, after transfering SOME(5~8GB) data, the speed drops down to 250MB/s using SATA2 bandwidth.
Looking for a solution, I found it is caused by a Intel Rapid storage technology driver. (Irst)
Uninstalling Irst makes the symptom gone away! (transfering speed is 460MB/s)
While I install irst (regardless of version) the bandwidth always go down to SATA2.
Why does this happen?
I tried rst version
Yes, I did update BIOS. *always uptodate checking thru the internet.
AFASK, Intel rst is not just for RAID system.
As a matter of fact, IRST makes my SSD 21% faster in 4K write !
I tested SATA link many times, it always works nice, but it's not the case for E-sata connection.
I think Intel didn't test e-SATA at all d/t it's not the common way to transfer data.