Is the sync necessary to commit a transaction slow? Performance of that sync depends on the OS, file system, hardwar, etc. IIRC, so IOs may be fast but it's possible that the syncs are killing you.
-T On Tue, Sep 22, 2009 at 5:14 PM, Mark <godef...@gmail.com> wrote: > Lothar Scholz wrote: >> Hello Mark, >> >> Tuesday, September 22, 2009, 3:53:48 AM, you wrote: >> >> M> I've currently got a loaner high-performance flash-based "SSD" (let's >> M> just say it doesn't connect to any disk controllers) that I'm testing >> M> for performance. I've run my application against it, and I believe that >> M> I should see numbers MUCH higher than I do. When I run my test app on a >> M> normal SATA 7200 RPM disk, I get a certain performance, and on the "SSD" >> M> I get about 1/10th that speed. On an array of SAS disks I get numbers >> M> that are about 5x faster than my SATA disk, so my software itself isn't >> M> (I believe) the bottleneck. >> >> M> I'm wondering if anyone has any tips for "optimizing" for this sort of >> M> storage solution. >> >> Throw it into the trash bin and buy a new one which has a 3rd >> generation controller and at least 64MB fast cache. The old JMicron >> controller that many low cost SSD still use was developed for Flash >> USB sticks. >> >> With modern SSD like the latest Samsung should give you at least the >> same performance as the SATA. If it gets better depends on file size >> and cache. Are you sure that the SAS RAID Controller is not keeping >> everything in the controller cache? > > This isn't an "SSD". It's connected directly to the PCI Express bus, and > "low cost" it certainly is NOT. It's much more valuable than the server > it's plugged into. > > I've run benchmark tests (iometer), and the benchmarks show it's as fast > as the mfgr says it should be (~700MB/sec read and write bandwidth, > >115,000 IOPS) but it performs quite poorly when I run my app on it. I > can't figure out why. > > Mark > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
