Corsair 2-2-2-5 & A8V works great, but beware...

To all,

I build a new system every few years. I'm not an overclocker at
heart. For me, stability and reliability are the prime goals. I'll
start by briefly presenting the lessons I've learned from my latest
build, so that those who already understand such lessons will be able
to skip my rather lengthy story.

Lesson 1) Make sure your RAM is being supplied the correct voltage,
especially when using those "special" low latency RAM modules that may
be specified at higher than standard voltages. Your motherboard may
not automatically supply those special voltages.

Lesson 2) Your computer may seem to be running your OS and
applications just fine even if your memory has occasional errors. You
should test your memory with a good memory testing program, because an
apparently fine running machine may have subtle memory errors that
could, over time, insidiously corrupt your programs and data.

Now for the story behind those lessons:

I recently built a new system (Asus A8V Deluxe, Athlon 64 3500). Just
for the hell of it, and quite out of character for me, I decided to
try some low latency ram -- two sets of Corsair TWINX1024-3200XLPT
(that's 2GB total). The install of XP Pro went smoothly on the new
system and everything seemed to be working fine. Later that day I
checked the RAM timings in BIOS and saw that they were not the 2-2-2-5
of the Corsair spec. Instead, the BIOS had set the timings to a more
relaxed spec. I therefore manually changed the BIOS memory timings to
2-2-2-5 and rebooted.

Great! Things seemed to be running just fine with the new RAM timing,
and my computer was faster too -- a computation of pi to 1 million
digits now took 2.29 seconds rather than the 2.44 seconds it took with
the previous RAM timings. BTW, exactly what I'll do with those one
million digits I don't know, but, if you are curious, a Google search
of "Pi Computation" will lead you to some sites that will reveal
exactly how far computing has come in the past few decades. Now, back
to my story.

After playing around with my new machine for a few more hours, I
decided to find a program to better test my RAM. Why? Well, as most
computer geeks know, the RAM test at POST is hardly exhaustive.
Google lead me to http://www.hcidesign.com where I downloaded their
free Memtest program. While running the program, I was quite
surprised to find occasional errors reported (about one error per 200
MB tested). Not acceptable!

I located the Corsair data sheet for the RAM on their web site and saw
that their timing tests were performed at 2.75 volts. Ah ha! The A8V
BIOS had set the RAM voltage to the more standard 2.5 V. After
changing the RAM voltage to 2.8 V in BIOS, I ran the Memtest program
again for over an hour with no reported errors. Satisfied that I had
fixed the problem, I then overclocked the machine (CPU + FSB) +5% for
a margin test and ran the Memtest again. With no errors reported, I
returned the computer to the normal clock rate. Margin tests like
that are important because otherwise you wouldn't know if your memory
was just teetering on the edge of failure, as it were.

I think the important lesson here is that if I hadn't decided to
perform the memory test, I could have gone for months or even years
with memory that was generating occasional errors. Surely such errors
would cause problems at some point, but being so rare I might well
have chalked the problems up to buggy software.

This is an important lesson, I think, for all of us who like to build
our own systems and who sometimes like to push the limits of our
hardwa A seemingly fine running machine may not be so fine after
all. You can't judge a computer's health merely on the fact that it
passes POST, boots the OS day after day, and runs your apps. Check
that RAM with a good memory testing program and if you get ANY errors,
find and fix the problem!

Cheers

David O wrote:
This is an important lesson, I think, for all of us who like to build
our own systems and who sometimes like to push the limits of our
hardwa A seemingly fine running machine may not be so fine after
all. You can't judge a computer's health merely on the fact that it
passes POST, boots the OS day after day, and runs your apps. Check
that RAM with a good memory testing program and if you get ANY errors,
find and fix the problem!

Indeed.

A good test for CPU stabilty is Prime95 torture test. This tends to throw a
fit MUCH sooner than you would notice in just about any other software.

Ben
--
A7N8X FAQ: www.ben.pope.name/a7n8x_faq.html
Questions by email will likely be ignored, please use the newsgroups.
I'm not just a number. To many, I'm known as a String...

GREAT points!!!! especially for new builders as well as some of us that
just forget!!

MikeSp
--------------------------------------
"David O" wrote in message
...


To all,

I build a new system every few years. I'm not an overclocker at
heart. For me, stability and reliability are the prime goals. I'll
start by briefly presenting the lessons I've learned from my latest
build, so that those who already understand such lessons will be able
to skip my rather lengthy story.

Lesson 1) Make sure your RAM is being supplied the correct voltage,
especially when using those "special" low latency RAM modules that may
be specified at higher than standard voltages. Your motherboard may
not automatically supply those special voltages.

Lesson 2) Your computer may seem to be running your OS and
applications just fine even if your memory has occasional errors. You
should test your memory with a good memory testing program, because an
apparently fine running machine may have subtle memory errors that
could, over time, insidiously corrupt your programs and data.

Now for the story behind those lessons:

I recently built a new system (Asus A8V Deluxe, Athlon 64 3500). Just
for the hell of it, and quite out of character for me, I decided to
try some low latency ram -- two sets of Corsair TWINX1024-3200XLPT
(that's 2GB total). The install of XP Pro went smoothly on the new
system and everything seemed to be working fine. Later that day I
checked the RAM timings in BIOS and saw that they were not the 2-2-2-5
of the Corsair spec. Instead, the BIOS had set the timings to a more
relaxed spec. I therefore manually changed the BIOS memory timings to
2-2-2-5 and rebooted.

Great! Things seemed to be running just fine with the new RAM timing,
and my computer was faster too -- a computation of pi to 1 million
digits now took 2.29 seconds rather than the 2.44 seconds it took with
the previous RAM timings. BTW, exactly what I'll do with those one
million digits I don't know, but, if you are curious, a Google search
of "Pi Computation" will lead you to some sites that will reveal
exactly how far computing has come in the past few decades. Now, back
to my story.

After playing around with my new machine for a few more hours, I
decided to find a program to better test my RAM. Why? Well, as most
computer geeks know, the RAM test at POST is hardly exhaustive.
Google lead me to http://www.hcidesign.com where I downloaded their
free Memtest program. While running the program, I was quite
surprised to find occasional errors reported (about one error per 200
MB tested). Not acceptable!

I located the Corsair data sheet for the RAM on their web site and saw
that their timing tests were performed at 2.75 volts. Ah ha! The A8V
BIOS had set the RAM voltage to the more standard 2.5 V. After
changing the RAM voltage to 2.8 V in BIOS, I ran the Memtest program
again for over an hour with no reported errors. Satisfied that I had
fixed the problem, I then overclocked the machine (CPU + FSB) +5% for
a margin test and ran the Memtest again. With no errors reported, I
returned the computer to the normal clock rate. Margin tests like
that are important because otherwise you wouldn't know if your memory
was just teetering on the edge of failure, as it were.

I think the important lesson here is that if I hadn't decided to
perform the memory test, I could have gone for months or even years
with memory that was generating occasional errors. Surely such errors
would cause problems at some point, but being so rare I might well
have chalked the problems up to buggy software.

This is an important lesson, I think, for all of us who like to build
our own systems and who sometimes like to push the limits of our
hardwa A seemingly fine running machine may not be so fine after
all. You can't judge a computer's health merely on the fact that it
passes POST, boots the OS day after day, and runs your apps. Check
that RAM with a good memory testing program and if you get ANY errors,
find and fix the problem!

Cheers

Thus spake David O:
Snipped
Lesson 1) Make sure your RAM is being supplied the correct voltage,
especially when using those "special" low latency RAM modules that may
be specified at higher than standard voltages. Your motherboard may
not automatically supply those special voltages.

Setting *all* FSB, CPU/DDR voltages & memory timings to manual is usually
the best approach. Doing so forces one to research more but seems to get
stable results with the best performance a lot quicker. Run memtest86 &
Prime95 but not /all/ stability problems are caught with either. XP's ACPI
Standby mode is shot on my PC at the moment, forcing me to use Hibernate
instead. I'll get round to troubleshooting this if the anomaly remains with
faster RAM. I've found this forum very informative:
http://www.nforcershq.com/forum/viewforum.php?f=13

--
Thank people in advance? Thanking or cursing them afterwards at least
gives some feedback!