On Monday, April 19, 2010, Roy Sigurd Karlsbakk <r...@karlsbakk.net> wrote: > ----- "Harry Putnam" <rea...@newsguy.com> skrev: > >> Erik Trimble <erik.trim...@oracle.com> writes: >> >> >> Do you think it would be a problem having a second sata card in a >> PCI >> >> slot? That would be 8 sata ports in all, since the A-open AK86 >> >> motherboard has 2 built in. Or should I swap out the 2prt for the >> 4 >> >> prt. I really only need 2 more prts currently, but would be nice >> to >> >> have a couple still open for the future. >> >> >> > Your PCI bus bandwidth is shared, so it doesn't matter if you use 3 >> x >> > 2port cards, or 2 x 4port cards (or, in your case, 1x2port + >> > 1x4port). Performance is going to be virtually identical. >> >> Thanks. >> So performance with drop as number of drives increases? > > Performance is likely to drop with the number of PCI cards on the same > bridge. Some motherboards have multiple PCI bridges, but mostly on more > expensive server boards (those with PCI-X etc). Performance will probably be > limited to the (theoretical) 133/266MB/s plus overhead with more PCI cards. > I'd say get an 8-port card to get the best out of it. I would guess your > motherboard supports 66MHz, since that came in PCI 2.1 (from wikipedia PCI > 2.1, released on June 1, 1995, allows for 66 MHz signaling at 3.3 volt signal > voltage (peak transfer rate of 533 MB/s), but at 33 MHz both 5 volt and 3.3 > volt signal voltages are still allowed. It also added transaction latency > limits to the specification.[7]). > > roy > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >
I'd be shocked to see 66mhz on a consumer board. In fact, i'd be shocked to see a 66mhz 32bit bus period. --Tim _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
