Re: Recommended pci-e 1x SATA cards.

[Roman Mamedov <rm@romanrm.ru>]

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On Thu, 14 Apr 2011 14:41:18 +0300
Tapani Tarvainen <raid@tapanitarvainen.fi> wrote:

> On Thu, Apr 14, 2011 at 05:25:28PM +0600, Roman Mamedov (rm@romanrm.ru)
> wrote:
> 
> > > > I suggest that you avoid Silicon Image 3132, they have data corruption
> > > > issue (on some board designs?), triggered or amplified by transferring
> > > > via both ports at the same time, at full speed.
> 
> > See this thread: http://comments.gmane.org/gmane.linux.raid/30629
> 
> Thanks! Based on that, it'd seem it's not so much Sil3132 per se,
> but some (too cheaply?) boards built around it

Maybe, but in my opinion a chip design should be 'well-rugged' against this
kind of board-design blunders, under no circumstance it should pass silent
corruption of user data just like that. There are checksums built in into the
SATA protocol, and parity in PCI-E, so the data path itself is protected quite
well against a flaky trace or solder or whatever. Silicon Image, on the other
hand, had multiple data corruption reports with 3112/3114/3124 in the past,
and many of those were fixable by turning off PCI performance optimizations,
i.e. likely logic-level chip design problems. So I suspect 3132 has some less
than ideal design decisions as well. And maybe some of those can be worked
around by adding more external components (e.g. bigger capacitors etc), which
are not present on cheaper board designs. So to me this seems to be a split
blame, both the board designers and the chip designer are at fault.

> and the obvious conclusion is that they should only be bought with plan to
> test them before real use and return flakey ones.

That's a good idea at all times.

> On the other hand I've had similar trouble with a JMicron card
> and a Marvell-based card. So planning to test and return
> bad cards is probably a good idea with them as well.

I have one semi-bad JMicron based card - its problem is manifesting itself as
one SATA port at first throwing a lot of CRC errors then switching itself down
to 1.5GBps from 3.0GBps, and continuing to work perfectly at the slower speed.
To me this is an example of error-handling done right.

-- 
With respect,
Roman

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