eric kustarz wrote: > On Jul 9, 2007, at 11:21 AM, Scott Lovenberg wrote: > > >> You sir, are a gentleman and a scholar! Seriously, this is exactly >> the information I was looking for, thank you very much! >> >> Would you happen to know if this has improved since build 63 or if >> chipset has any effect one way or the other? >> > > Naw. Without having information on how exactly the controller/disk > firmware really works, we're merely speculating that the firmware is > where the problem is. Getting that information from the disk vendors > is <ahem> tricky. >
Unfortunately, testing has not support the theory that the problem is with the controller hardware, driver, disk or disk firmware. So far every valid measurement with using FPDMA READ/WRITE (NCQ) v. READ/WRITE DMA EXT. has shown anywhere from less that 1% improvement using NCQ to up to 22% improvement. The biggest improvements are seen when the disk caches are disabled, but I have measured up to 19% improvement w.r.t. time spent waiting for I/Os to complete with the caches enabled. > More investigation is needed. > Absolutely more investigation is needed. > eric > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
