I thought I would share some of my testing results using both the latest AMD AHCI (amd_sata.sys: 22.214.171.1242) and MS AHCI (msahci.sys: 6.1.7601.17514 win7-sp1) drivers with my Plextor 128GB SSD drive (PX-128M2S). The results are that the MSAHCI driver was far superior in read operations with slightly imroved write function. For whatever reason - here are the results:
This is with amd_sata.sys:
This is with msahci.sys:
What I find most interesting was how the write cache seems to get downgraded to a slower sata speed in ATTO under amd_sata.sys driver that is ultimately what is preventing my drive from running at a higher speed.
All of this was instigated by the fact that my windows experience index for this drive is 7.6. I expected a very high 7.8+ for this drive but have been unable to attain it. WritePrefetch and caching have all be disabled, TRIM/NCQ are active. Seems like it should go a bit faster - if anyone has any ideas?