On Wed, Aug 22, 2012 at 4:46 PM, Mark Knecht <[email protected]> wrote: > Hi, > Yesterday I got a new, but rather low-end, PCIe-2 SATA-3 6Gb/S > adapter card and a reportedly high performance 128GB SSD drive. (Links > below) Other than my swap getting messed up because it didn't use > labels (who knew about swaplabel but didn't tell me? ;-) ) the
"mkswap -L name /dev/sdX" :) > adapter and drive are in the machine and working fine. Unfortunately > the performance isn't what I might have hoped for. Both hdparm & > bonnie++ are reporting numbers in the 200MB/S range rather then the > 400-500MB/S range that I might have hoped for. The machine is PCIx-2 > based according to its specs. > > I'm currently just using a single large partition & ext3. I didn't > do anything special in fdisk so the partition might not be aligned as > best it could be. I don't know. > > I'm wondering what sort of experience folks have had trying to get > performance numbers anywhere close to these specs? Because it is a PCIe x1 slot card, that is the bottleneck. Based on all I have read, your speeds are normal and you should consider it to be the fastest speeds you'll see. If you had bought two SSDs and used them in a RAID configuration, the speed would actually get worse. I ran into the same thing a while back, my motherboard actually has SATA3 on-board, but it is not the primary controller (that one is SATA2) and it's basically a permanently-installed PCIe controller as far as speeds are concerned. Because of added latency, the on-board primary SATA2 is actually faster than the SATA3 when multiple drives are attached... but it's still faster than a HDD anyway. I think the only way we'lll see 500MB/sec on that SSD is to buy a motherboard which has a SATA3 controller as its primary on-board drive controller and plug it in to that. Look on the bright side, someday when we upgrade our motherboards, it'll be like we got a free SSD upgrade for our troubles. :)
