Alexander Motin wrote:
Steve Polyack wrote:
On 2/10/2010 12:02 AM, Dan Langille wrote:
Don't use a port multiplier and this goes away. I was hoping to avoid
a PM and using something like the Syba PCI Express SATA II 4 x Ports
RAID Controller seems to be the best solution so far.
http://www.amazon.com/Syba-Express-Ports-Controller-SY-PEX40008/dp/B002R0DZWQ/ref=sr_1_22?ie=UTF8&s=electronics&qid=1258452902&sr=1-22
Dan, I can personally vouch for these cards under FreeBSD. We have 3 of
them in one system, with almost every port connected to a port
multiplier (SiI5xxx PMs). Using the siis(4) driver on 8.0-RELEASE
provides very good performance, and supports both NCQ and FIS-based
switching (an essential for decent port-multiplier performance).
One thing to consider, however, is that the card is only single-lane
PCI-Express. The bandwidth available is only 2.5Gb/s (~312MB/sec,
slightly less than that of the SATA-2 link spec), so if you have 4
high-performance drives connected, you may hit a bottleneck at the
bus. I'd be particularly interested if anyone can find any similar
Silicon Image SATA controllers with a PCI-E 4x or 8x interface ;)
Here is SiI3124 based card with built-in PCIe x8 bridge:
http://www.addonics.com/products/host_controller/adsa3gpx8-4em.asp
It is not so cheap, but with 12 disks connected via 4 Port Multipliers
it can give up to 1GB/s (4x250MB/s) of bandwidth.
Cheaper PCIe x1 version mentioned above gave me up to 200MB/s, that is
maximum of what I've seen from PCIe 1.0 x1 controllers. Looking on NCQ
and FBS support it can be enough for many real-world applications, that
don't need so high linear speeds, but have many concurrent I/Os.
Is that the URL you meant to post? "4 Port eSATA PCI-E 8x Controller
for Mac Pro". I'd rather use internal connections.
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
