Search found 2 matches

by redstorm
Thu Apr 30, 2015 2:47 pm
Forum: Storage
Topic: Samsung SM951 AHCI SSD Performing Poorly At Sub-4k File Size
Replies: 6
Views: 16645

Re: Samsung SM951 AHCI SSD Performing Poorly At Sub-4k File

The reason the microsoft driver is issuing FUA IO commands to the SM951 is quite simple. The SM951 does not have a battery backed cache, so it cannot guarantee writes in a power loss situation. This is not the case with the Intel 750 as they have full power loss protection and hence FUA IO commands ...
by redstorm
Mon Apr 27, 2015 2:28 pm
Forum: Storage
Topic: Samsung SM951 NVMe M.2 PCIe Drive - Low Performance on SSD
Replies: 7
Views: 17046

Re: Samsung SM951 NVMe M.2 PCIe Drive - Low Performance on S

Apparently Microsofts drivers is issuing a Forced IO command that causes the drive to bypass the DRAM cache and write directly. This of course kills performance. Similar to write through cache policy's on raid controllers. http://www.sqlskills.com/blogs/glenn/beware-of-the-native-microsoft-nvme-driv...