Bill Anderson wrote:
It began happening a few weeks ago -- I'd try to boot but before post
I'd hear four short beeps followed by the post chirp (different sound)
and then nothing. But it was an intermittent problem and I let it go
when rebooting seemed to solve things.

Then yesterday the problem stuck around through several attempted
reboots and I figured I'd better do something. So I looked up the error
beep table on the Asus website and found nothing about four short beeps.
Thanks, Asus. Then I branched out and learned Asus uses American
Megatrends' AMI BIOS, and that four beeps mean System Timer Failure,
which further means something's wrong with memory.

That was when I actually looked at BIOS to see how much memory I had and
I learned my four 8-gig memory sticks were producing not 32 gigs of
memory, but just 8 and change. In other words, only one stick was working.

So just now I removed all the memory and began replacing sticks one at a
time. At first I couldn't get past the four beeps, but I kept replacing
sticks in the D1 slot until one worked. (The manual says to put a
single stick in D1.) Then I put a stick in B1 as shown in the manual and
went right back to the four error beeps.

But I persevered, removing and re-inserting, and eventually I had two
working, then four, and now I'm booting nicely and BIOS shows total
memory at 32 gigs and change.

Funny things was -- the AIDA 64 Extreme system monitor software always
showed four slots filled with 8-gig sticks. It saw them when BIOS
didn't. Weird.

But things are fine now. I think. Maybe I oughta run Memtest just to be
sure...


Memory is detected two ways at BIOS level.

1) Read config info from SPD PROM on each DIMM.

2) Once the BIOS knows a DIMM is present, it uses "peek & poke"
testing to prove "a RAM is a RAM" and that it can actually
store stuff.

One of the "proof cases" for this, was the day when
some brand of DIMMs, had the wrong SPD chip soldered
to them. The DIMM may have declared it had 256MB on it,
when the physical chips were 128MB. The BIOS (correctly)
did "peek & poke" and measured 128MB, and the system
started just fine and ran with the reduced amount
of memory. Because in fact, that's all the physical memory
that was present on the stick.

This issue seemed to first show up on triple channel memory.
Maybe a 12GB system would be detected as an 8GB system. At
first, people might have tried blaming a "socket contact"
issue for the problem.

Then later, people started randomly adjusting the IMC or
VNorthbridge. And then there were claims that this
was "fixing it".

I don't know if I've ever seen a company web site
(Asus or Intel) making claims as to why this happens.

When the OS is running, hardware identification software
continues to have access to the SPD and can then
claim that 32GB are "installed", even if the BIOS
has tested and chosen to only use a subset, because
"peek & poke" is failing.

"Peek & poke" is a quick check of memory presence and
does not represent a full memory test. That may come
later in the POST, if the user has enabled it.

*******

And yes, doing some memtest is a good idea.
Between that, and something like Prime95, you'll get
a better idea whether it's really working properly or not.

Paul