On Wed, May 26, 2010 at 9:22 PM, Brandon High <bh...@freaks.com> wrote: > On Wed, May 26, 2010 at 4:27 PM, Giovanni Tirloni <gtirl...@sysdroid.com> > wrote: >> SuperMicro X8DTi motherboard >> SuperMicro SC846E1 chassis (3Gb/s backplane) >> LSI 9211-4i (PCIex x4) connected to backplane with a SFF-8087 cable (4-lane). >> 18 x Seagate 1TB SATA 7200rpm >> >> I was able to saturate the system at 800MB/s with the 18 disks in >> RAID-0. Same performance was achieved swapping the 9211-4i for a >> MegaRAID 8888ELP. >> >> I'm guessing the backplane and cable are the bottleneck here. > > I'd wager it's the PCIe x4. That's about 1000MB/s raw bandwidth, about > 800MB/s after overhead.
Makes perfect sense. I was calculating the bottlenecks using the full-duplex bandwidth and it wasn't apparent the one-way bottleneck. In any case the solution is limited externally by the 4 x Gigabit Ethernet NICs, unless we add more, which isn't necessary for our requirements. Thanks! -- Giovanni _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
