On Thu, Feb 08, 2007 at 02:51:58PM -0800, Freddie Cash wrote: > On Thursday 08 February 2007 02:17 pm, Mike Andrews wrote: > > Jaime Bozza wrote: > > > Everyone has their reasons - I liked the RAID 6 feature, plus the OOB > > > management of Areca, plus my history with 3ware wasn't good. :( > > > > For what it's worth, 3Ware's latest PCI-E cards (9650 series) now > > support RAID 6. The updated twa driver that supports them hasn't yet > > been merged into FreeBSD (see kern/106488 which I filed 2 months ago) > > but you can download either the source or the binary for it from 3Ware > > that works just fine. The updated 3dm2 for it did make it into the > > Ports tree. > > > > Driver annoyances aside, my 9650SE is considerably faster than my 9500S > > Not all that surprising, since the 9500-series use PATA-133 chipsets with > SATA-PATA bridges, and the 9550+ uses a native 3G SATA chipset. Even > though the 9500s are listed as 1.5G SATA parts, you'll never get better > than ATA-133 speeds out of them.
Which is quite irrelevant since there are no SATA-disks which actually can use more speed than that. (The fastest SATA-disks currently available -- Western Digital's Raptor series has a maximum transfer rate of just under 90 MB/s. Most disks are significantly slower than that.) The 133 MB/s one can get out of ATA-133 is quite enough for that (and not all that much less than the 150MB/s that normal SATA provides. (Some SATA devices also provide a 300MB/s transfer speed, but since no disks can keep up with that it does not make all that much of a difference in practice.)) Just about all reviews that have compared both controllers and disks with and without SATA-PATA bridges have come to the conclusion that those bridges do not cause any measurable drop in performance over their native-SATA counterparts. The only real drawback with using SATA-PATA bridges is that you cannot get support for the optional SATA features like NCQ. (But not all native-SATA solutions support those features either.) > > We didn't realise that when we ordered our first pair of Escalade 9500S > 4-port cards. Thankfully, just after they arrived and before we put in > the mass-order, the 9550SX was released and we've standardised on them. The 9550SX should be a bit faster than the 9500S and the 9650SE faster still, but that is for other reasons. (Faster processor for handling the parity calculations for RAID-5, faster memory on the card, being able to do more operations in parallell, etc.) -- <Insert your favourite quote here.> Erik Trulsson [EMAIL PROTECTED] _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
