Memtest 86, as several have correctly stated, is used to test the stability
of RAM (after you have set the fsb and timings). You can run it from a
bootable floppy or CD. Memtest 86 is generally perceived as the best
program out there for testing RAM. If fact, some motherboard manufacturers
value the program so highly that the code for Memtest is written into the
bios.
However, my reason for posting to this thread is to address a couple of
idiotic statements from those who would tell you to set your memory at
default and leave it alone. That type of response is way off base and has
no constructive value in a forum like this.
On the contrary, someone who doesn't know what/how to set
their memory to anything besides the default, should defer
to the combination of memory manufacturer's SPD programmed
timings, as read (and adjusted per the motherboard
designer's desires) and used by the bios.
It would be ill-advised to not use the default bios setting
until there is a specific reason to change it.
Let me give you a few reasons
for testing memory:
1. Some memory, even high end memory, will not run stably at default
settings. If you don't care what caused your computer to "blue screen" or
freeze up, then just set you memory to the default settings and go. The
only way to know if your memory is performing as it should is to test it.
Just last week, I RMA'd two sticks of high end dual channel memory because
they would not run stable even with the fsb lowered and the timings
loosened.
You are missing the point. If a premium was paid for this
"high end" memory, it should run at the default timings
which are those programmed by the memory manufacturer. If
those aren't stable it is beside the point whether lower bus
or timings are stable, because the premium price paid was
specificially to not have to use the lower settings/slower
performance. There is no reason to test at lower speed
unless still trying to isolate which part is the problem,
when the opportunity to RMA the modules is present.
2. Not all RAM has the SPD programmed for maximum performance. Example:
The Corsair XMS memory in my computer, advertised and sold as 2-3-3-6 memory
at 200 fsb, is programmed by the SPD to run 3-3-3-8 timings at 200 fsb. In
actuality, my memory runs happily at 2.5-3-3-6 timings at 220 fsb with no
increase in voltage (or heat). I acknowlege that these differences are not
noticeable with most software, but why not make the equipment perform as it
is supposed to?
This is a good point you make, but that is, unlike the
generic statement to use the defaults, a special case where
you know a specific reason to change from the defaults.
3. If you overclock to any extent, then testing your memory is extremely
important for ending up with a stable system. I'm not a proponent of
extreme overclocking, but I am a tweaker. And I don't normally mess with
voltages (with increased heat) just to get a little more performance out of
a piece of hardware. However, it is very satisfying to make a $200
component perform like a $300 component with no other sacrifice whatsoever.
There is so much headroom in today's cpus and ram, that the added
performance is there free for the taking.
Thanks for listening to my rant.
You are entitled to your opinion, but it seems a bit more
subjective about specific situations. In other situations
it is expected the memory timings are read correctly and
applied correctly already, it would only be a matter of
changing them after some problem or desire to overclock.
