A question about RAM testers

[da_test]

Hello,
I bought some "value" RAM for my KT133a - based system.
It's clearly designed to operate at CL3,
atempts to use it at CL2 caused a variety of sysmptoms
in windows, such as unexpected application hangs,
screen glitches that wouldn't clear until a reboot,
etc,etc.

Running the memory at cl3 restores normal operation.
But here's my point.
Running memory testers such as windiag and memtest+
show absolutely NO errors, even when the test is
run with the memory speed set to CL2 in the BIOS.

Seems like Windows, running the real-world environment
can exercise the memory and reveal memory problems that the
best RAM tester cannot detect.
Comments?

Dave

 

[Al Dykes]

Hello,
I bought some "value" RAM for my KT133a - based system.
It's clearly designed to operate at CL3,
atempts to use it at CL2 caused a variety of sysmptoms
in windows, such as unexpected application hangs,
screen glitches that wouldn't clear until a reboot,
etc,etc.

Running the memory at cl3 restores normal operation.
But here's my point.
Running memory testers such as windiag and memtest+
show absolutely NO errors, even when the test is
run with the memory speed set to CL2 in the BIOS.

Seems like Windows, running the real-world environment
can exercise the memory and reveal memory problems that the
best RAM tester cannot detect.
Comments?

Dave

A common observation, and IMO, true.

 

[Sleepless in Seattle]

The problem exists with XP and Unix/Linux certainly if RAM sticks are mixed
brand as some brands just aren't up to it. Keep exclusively to one brand at
a time and ask advice in the motherboard newsgroups.

 

[SFB - KB3MM]

"Value" !? RAM

Always think of Crucial.cpm for RAM.

 

[da_test]

"Value" !? RAM

Always think of Crucial.cpm for RAM.

My original stick was Crucial.
Added 256mb Viking generic SDRAM pc133.

One odd thing about Viking is that they purport to have
specific memory designed for the partiular brand of
motherboard. (which I didn't get since it cost more)
Never seen that before.

Since the crucial was already at cl3, I didn't think it
would matter. Generally the system is OK running at that
setting.
Cheers,
Dave

 

[Alex Nichol]

Running the memory at cl3 restores normal operation.
But here's my point.
Running memory testers such as windiag and memtest+
show absolutely NO errors, even when the test is
run with the memory speed set to CL2 in the BIOS.

Seems like Windows, running the real-world environment
can exercise the memory and reveal memory problems that the
best RAM tester cannot detect.

Windows has some critical timing loops and complains bitterly if they
are thrown out. This may happen through mismatched modules, or through
running at too few wait states, so that accesses get retries. The
testers will not object provided a second try does result in correct
results

Don't try running RAM at a faster CL setting than specified, it will
probably end up slower though retries.

 

[da_test]

Windows has some critical timing loops and complains bitterly if they
are thrown out. This may happen through mismatched modules, or through
running at too few wait states, so that accesses get retries. The
testers will not object provided a second try does result in correct
results

Don't try running RAM at a faster CL setting than specified, it will
probably end up slower though retries.

Thanks for the info Alex.
Never perceived anything to be slower,
but rather, applications would hang or mysteriously
crash. The apps in general put quite a demand on the
system, such as usenet header download/ sqlite database,
and mpg encoding using tmpgenc.

The odd thing is my original crucial stick was supposedly
cl2, although I found the system to be unreliable when
using it and used cl3 instead.
My cheaper second stick definitely cl3.

The second thing is, my bios allows other timings which I
don't quite under stand. For example,
normal 6-3-3
enhanced 6-3-2
fast 6-2-3
faster 6-2-2
Beyond these settings, there's a separate cl2/cl3 setting
which is completely independant. Seems like they can
contradict each other?
Dave

 

[frodo]

I would suspect your power supply and/or the voltage going to the ram
sticks.

If memtest86+ shows zero ram errors, after running for at least an hour
(overnight is better) then I'd say your mem is fine.

The fact that you're getting errors in windows anyway points to the PS.
In windows there are other drains on the power, such as HD/CD, video
processing etc. memtest basicaly just taxes the ram, not the PS.

--------------

Also, a ram that's spec'd at CL3 is definately not going to work very well
at CL2, no matter what. If it did they'd sell it as CL2, which commands a
much higher price! You might be able to push the clock up over spec, but
that first timing number is difficult to push.