Thread (10 messages) 10 messages, 5 authors, 2004-10-16

Re: 3Ware 7506-8, anyone have any luck? I don't...

From: KELEMEN Peter <hidden>
Date: 2004-10-15 18:44:10

[ Please do not address answers directly to me; I read the list. ]

* Scott T. Smith (scott@gelatinous.com) [20041015 11:21]:
You know what, I think I was wrong -- we have the 8506.  Sorry,
my bad.  And ours is SATA, not PATA (is that the difference
between the 7xxx and 8xxx?)
Yes.
There are other reasons the Highpoint is better than the 3ware,
including the fact that it instantly recognizes when you yank a
disk, unlike the 3ware which sits there for a while, and then
hard resets the entire controller (thus halting all disk io to
that controller for a couple of seconds).  3ware wrote me back
and told me it's supposed to do that!
Cannot comment on this one, never was a problem for us.
Is the 9500 a PCI-X card?
No, it's 64-bit 66 MHz PCI.
http://www.3ware.com/products/pdf/9000DS_041904.pdf
[...] and we get the same crappy performance from that one too.
Define `crappy': I get 770 MiB/s read with 3x 3ware 9500S-8MI.
(RAID00 hw-sw)
Worse yet, the 9xxx series wants to hijack your disks unless you
go out of your way to enable 'export JBOD' mode.  You can't take
a disk from a 9xxx controller and put it in a box with an 8506
-- the controller won't recognize it!
Have you tried zapping the first and the last megabyte of the
disk?
BTW I'm not talking about RAID or filesystem performance, I'm
talking about direct disk access, JBOD mode, using rather large
blocks.
Direct disk access gives me nominal disk throughput on 3ware.
So really all I want is multiple controllers on a single card.
To that end, the 1820a works great.  I figure we'd all be
running software RAID anyways ;-)
As I said, attractive pricing.  Cannot get stellar hardware RAID
performance with crappy chipsets. :-)  There's a turnover point
where you are killed by PCI bandwith limit when using a lot of
disks.

Peter

-- 
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