shaky support or my system?

[Bob Willcox]

On Thu, Feb 05, 2004 at 10:27:21AM -0600, James Van Artsdalen wrote:
> > Date: Thu, 5 Feb 2004 07:45:51 -0600
> > From: Bob Willcox <bob at immure.com>
> > 
> > On Wed, Feb 04, 2004 at 03:30:11PM -0600, James Van Artsdalen wrote:
> > > Unfortunately it appears my case was a false alarm.
> > > My Tyan K8W S2885 is not stable unless ECC is turned off in ROM setup.
> > 
> > Could you guys post what kind of memory (brand and part no. if possible)    
> > you are using?
> 
> I'm using 8x Crucial part #CT12872Y335 with Opteron 2x 244.
> 
> There's no way to tell if this is a problem with the RAM or not.
> My gut suspicion is a BIOS bug, but it could well be the motherboard.
> There's really no evidence it's problem with the DIMMs.
> 
> (the system is not reporting a memory error.  It's incredibly unlikely
> any sort of problem in the DDIM would fail to show up at some point as
> an ECC error, and ECC errors are not being reported by the system.
> The symptom is that FreeBSD gets the wrong data back from a read and
> no ECC error)

Well, my early Tyan Athlon MBs (Tiger S2460) didn't like Crucial
DIMMs much, and my later Tyan boards (Tiger s2466's) won't work with the
Crucial DIMMs at all (I have about 8 of them on a shelf that I can't
use at all now). I never have seen any ECC errors (there registered ECC
DIMMs) with these, just varying degrees of system unstability (random
memory erors/panics). A couple of years ago I spent quite a bit of time
on the phone with Crucial's tech support folks (shortly after I bought
the memory) with no real resolution (the tech support guy tried to be
helpful but couldn't really help).

Following this experience, I have come to worry much more than I
previously did about memory compatibility issues; and I began to wonder
just how much good ECC memory really does in these systems when you
wind up with all kinds of system instability. I now worry more about
compatibility than do ECC vs. non-ECC memory.

Note, that my newer Tyan dual MB systems (those with the S2466 MBs
that can run with unbufferred/non-ECC DIMMs) have been running with
unbufferred/non-ECC DIMMs for some time (over a year) and I have had
much better stability with these systems than when I tried the Crucial
reg/ECC DIMMs (generally, they either wouldn't boot at all or only
ran for a short time, depending on how many DIMMs I installed--more
meant shorter time to crash). Note that I never did try other brands of
reg/ECC memory on these systems since they were stable with the cheaper
stuff and I was growing tired of spending money on them.

Bob

-- 
Bob Willcox                     If facts do not conform to the theory,
bob at immure.com                  they must be disposed of.
Austin, TX