Dagger wrote:
> I have a P4C800 Deluxe
>
> My question is: I have 4 X 1 GIG DDR just installed (all sticks identical)
> CPUZ says I have 4+ Gig of DDR installed.
> Belarc says all DDR slots are filled with 1024 meg
>
> But when the computer boots, the ASUS BIOS Screen only recognizes 2558 GIG
> Latest BIOS installed
> 512 MEG AGP Video card installed
>
> does anyone know why the BIOS is only recognizing 2558GIG
>
> Thanks
>
>
That number pops up in this post, but the guy was using 3GB total of RAM.
Which suggests one stick is not being recognized or something.
http://www.psdata.no/forum/topic.asp?TOPIC_ID=4077
I recommend some memtest86+ testing (memtest.org).
These are the test cases I would recommend.
Slot testing.
1) Take a single stick of RAM. Insert it in each of the four memory
slots. Verify the BIOS quick memory test, records "1024" or so
megabytes present. Press <Del> to enter the BIOS and then power
off and run the next test case. Total: 4 test cases.
If any slot fails, then you have a bad slot. If all slots fail,
then you have a bad stick.
2) Now that you've established at least one good slot, test all four
sticks individually, using a single slot. You've already done
one test case for this, so this adds 3 more test cases.
You can run memtest86+ from a floppy or CD, for each stick in this
test. You don't have to wait for an entire pass to complete. Perhaps
just the first three or four tests would be enough. If a stick is
really bad (like a stick I have here, with one whole busted memory
chip), the BIOS cannot start anyway, so you don't need a memtest
run for that.
3) Now that all slots pass, and all sticks pass, you can try other
combinations. For example, try your 4x1024 case, record the amount
of memory seen in the BIOS, and the amount of memory reported in
memtest86+. Next, try a 3x1024 case, and see what numbers result
from that. Memtest should honor the BIOS memory reservation function,
so memtest should be reporting the maximum amount of memory that
is being made available by the BIOS. Memtest cannot test anything
the BIOS happens to mark as reserved.
I suppose it could be a BIOS problem. You could check the download
page and see if the BIOS release notes make note of a memory map
problem or not. (Unfortunately, the BIOS release notes only cover
releases 1010 to 1024.001, so it isn't possible for me to comment
on BIOS releases before 1010. I don't see anything in the available
info that is relevant.)
The experience here seems to match yours. It almost looks like the
BIOS only detects 3GB (3072) of the 4096. Maybe this is an address
map issue of some sort, like a resource conflict. The guy here posted
some CPUZ output, which shows the SPD info from the four sticks, but
that doesn't make any difference to the real problem, which is happening
at the BIOS level. The BIOS "plans" the address map for the system,
and the OS cannot change it. The BIOS passes reserved memory info to
the OS, via E820 standard. So the BIOS is "driving the bus" and not
the OS. What the BIOS says, goes. For example, the BIOS sets the
"Top of Memory" register, which is part of the decoding logic.
http://vip.asus.com/forum/view.aspx?...Language=en-us
More info here.
http://www.abxzone.com/forums/f41/4g...ods-53438.html
It could be, that a different BIOS solves this problem. You could
try disabling resources in the BIOS (like perhaps disable USB ports
temporarily), and see if you can change the BIOS behavior that way.
The 875P has an AGP aperture setting, but according to the datasheet,
that only goes as high as 256MB. So I don't think that is what is
doing it. I think the BIOS is "freaked out" at finding 4096MB, and
is tossing a stick away for whatever reason.
Paul
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