Subject: Re: softdep and memory...?
To: Mason Loring Bliss <>
From: Guenther Grau <>
List: current-users
Date: 02/29/2000 14:00:53
Mason Loring Bliss wrote:
> Just on a whim, I turned off softdep everywhere, and noted a complete lack
> of instability. Then, feeling dangerous, I popped in my old "bad" 128 meg
> SIMM and noticed a similar lack of instability. The only condition different
> between the instability and the stability was the amount of RAM present in
> the system.

Did you enable softdeps again after that?

> Is it possible that softdep simply can't deal with large amounts of RAM? I
> was running softdep okay with 64 megs of RAM, but having more seems to be
> an irritant to softdep.

Might be, but I don't think so. Softdep exercises memory a lot, 
so it might be a good testtool :-)

> I'm going to change the order of my RAM anyway such that the old, "bad" SIMM
> is first and hence used more, just to try to rule out the possibility that it
> is in fact bad but just not being used right now, but I'm curious about
> whether it would be worth building a fresh system as well, once the "flaky"
> RAM has had a chance to prove itself. (This RAM survived nine hours of testing,
> so I wouldn't be madly surprised to find that it's not bad.)

What sort of tests did you run? IIRC, there are special free 
mem testtools that you're supposed to run for about a day or so. 
That should give you more confidence.
Besides that, slot position of SIMMS
(i.e. 1. slot or last slot) might be important for some boards.
Several large modules sometimes cause problems in certain mainboards
as well. Sometimes it's fixable by a bios upgrade, sometimes
not. Sometimes different modules work, sometimes they don't :-)
Memory has always been one of the weaker parts of PCs. ECC memory
helps a lot, but it's d*mn expensive.