Tim wrote: > > > On Wed, Jun 25, 2008 at 10:44 AM, Bob Friesenhahn > <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> > wrote: > > I see that the configuration tested in this X4500 writeup only uses > the four built-in gigabit ethernet interfaces. This places a natural > limit on the amount of data which can stream from the system. For > local host access, I am achieving this level of read performance using > one StorageTek 2540 (6 mirror pairs) and a single reading process. > The X4500 with 48 drives should be capable of far more. > > The X4500 has two expansion bus slows but they are only 64-bit 133MHz > PCI-X so it seems that the ability to add bandwidth via more > interfaces is limited. A logical improvement to the design is to > offer PCI-E slots which can support 10Gbit ethernet, Infiniband, or > Fiber Channel cards so that more of the internal disk bandwidth is > available to "power user" type clients. > > Bob > ====================================== > Bob Friesenhahn > [EMAIL PROTECTED] > <mailto:[EMAIL PROTECTED]>, > http://www.simplesystems.org/users/bfriesen/ > GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org <mailto:zfs-discuss@opensolaris.org> > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > > > Uhhh... 64bit/133mhz is 17Gbit/sec. I *HIGHLY* doubt that bus will be > a limit. Without some serious offloading, you aren't pushing that > amount of bandwidth out the card. Most systems I've seen top out > around 6bit/sec with current drivers. Ummm 133MHz is just slightly above 1/8 GHz. 64bits is 8 x 8 bits. Multiplying yields 8Gbits/sec or 1GByte/sec. So even if you have two PCI-X (64-bit/133MHz slots) that are independent, that would yield at best 2GB/sec. The SunFire x4500 is capable of doing > 3GB/sec I/O to the disks, so you would still be network band limited. Of course if you are using ZFS and/or mirroring that >3GB/sec from the disks goes down dramatically, so for practical purposes the 2GB/sec limit may well be enough. > > > ------------------------------------------------------------------------ > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >
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