Jeff, Some off topic questions: Is it possible to boot the OS from the ioDrive? If so, is the difference in boot up time noticeable? Also, how does ioDrive impact compilation time for a moderately large code base? What about application startup times? Cheers, Behrang Jeffrey Baker wrote: > > For background, please read the thread "Fusion-io ioDrive", archived at > > http://archives.postgresql.org/pgsql-performance/2008-07/msg00010.php > > To recap, I tested an ioDrive versus a 6-disk RAID with pgbench on an > ordinary PC. I now also have a 32GB Samsung SATA SSD, and I have tested > it in the same machine with the same software and configuration. I > tested it connected to the NVIDIA CK804 SATA controller on the > motherboard, and as a pass-through disk on the Areca RAID controller, > with write-back caching enabled. > > Service Time Percentile, millis > R/W TPS R-O TPS 50th 80th 90th 95th > RAID 182 673 18 32 42 64 > Fusion 971 4792 8 9 10 11 > SSD+NV 442 4399 12 18 36 43 > SSD+Areca 252 5937 12 15 17 21 > > As you can see, there are tradeoffs. The motherboard's ports are > substantially faster on the TPC-B type of workload. This little, cheap > SSD achieves almost half the performance of the ioDrive (i.e. similar > performance to a 50-disk SAS array.) The RAID controller does a better > job on the read-only workload, surpassing the ioDrive by 20%. > > Strangely the RAID controller behaves badly on the TPC-B workload. It > is faster than disk, but not by a lot, and it's much slower than the > other flash configurations. The read/write benchmark did not vary when > changing the number of clients between 1 and 8. I suspect this is some > kind of problem with Areca's kernel driver or firmware. > > On the bright side, the Samsung+Areca configuration offers excellent > service time distribution, comparable to that achieved by the ioDrive. > Using the motherboard's SATA ports gave service times comparable to the > disk RAID. > > The performance is respectable for a $400 device. You get about half > the tps and half the capacity of the ioDrive, but for one fifth the > price and in the much more convenient SATA form factor. > > Your faithful investigator, > jwb > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance > > -- View this message in context: http://www.nabble.com/Samsung-32GB-SATA-SSD-tested-tp18601508p19282698.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com.
