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

[KELEMEN Peter <Peter.Kelemen@cern.ch>]

[ 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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 Kelemen Péter     /       \       /       \     Peter.Kelemen@cern.ch
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