On Wed, Jun 25, 2008 at 3:13 PM, Lida Horn <[EMAIL PROTECTED]> wrote:
> 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 >> >> > > Actually 8.5Gbit, I was looking at the DDR line of my chart :)
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