Asus P-299 MotherBoard memory upgrades??

  • Thread starter Thread starter lpender
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lpender

I have the Asus P-299 MotherBoard

I'm trying to upgrade to the memory from SDRAM 128.



However. if I insert a..

SDRAM 256 chip in socket 1 - the system will not boot up, and I get beeps
and distorted colors on monitor.



If I insert a ...

SDRAM 128 (or lower) chip in socket 1 and the SDRAM 256 chip in socket 2



The system will boot-up.. to WinXP (clean install).. but it becomes unstable
and crashes.



If I insert a ...

SDRAM 256 chip in socket 1 and the SDRAM 128 (or lower) chip in socket 2



The system will boot-up.. to WinXP (clean install).. But it becomes unstable
and crashes.



Then, on the next boot, I get the beeps and the distorted colors on monitor.



I removed all of the other cards from the board and tried a different video
card as well.



According to the MB's user manual, I should be able to install the 256 chip.

(From the user manual)



System Memory (DIMM)

Socket 1 (Rows 0&1) - SDRAM 8,16,32,64,128,256

Socket 2 (Rows 0&1) - SDRAM 8,16,32,64,128,256

Max Memory: 512



Is there a setting in the BIOS that I can change to correct this problem?



Any input would be greatly appreciated..



Thanks..
 
"lpender" said:
I have the Asus P-299 MotherBoard

I'm trying to upgrade to the memory from SDRAM 128.

However. if I insert a..

SDRAM 256 chip in socket 1 - the system will not boot up, and I get beeps
and distorted colors on monitor.

If I insert a ...

SDRAM 128 (or lower) chip in socket 1 and the SDRAM 256 chip in socket 2

The system will boot-up.. to WinXP (clean install).. but it becomes unstable
and crashes.

If I insert a ...

SDRAM 256 chip in socket 1 and the SDRAM 128 (or lower) chip in socket 2

The system will boot-up.. to WinXP (clean install).. But it becomes unstable
and crashes.

Then, on the next boot, I get the beeps and the distorted colors on monitor.

I removed all of the other cards from the board and tried a different video
card as well.

According to the MB's user manual, I should be able to install the 256 chip.

(From the user manual)

System Memory (DIMM)

Socket 1 (Rows 0&1) - SDRAM 8,16,32,64,128,256
Socket 2 (Rows 0&1) - SDRAM 8,16,32,64,128,256
Max Memory: 512

Is there a setting in the BIOS that I can change to correct this problem?

Any input would be greatly appreciated..

Thanks..
Click to expand...

One way to analyse the problem, is to go to www.crucial.com and
look up what memory is recommended for your board. I compared P2-99
to P2B-S (my mobo), and the 256MB sticks recommended are the same.
The P2B-xx family uses the 440BX chipset, and that chipset has a
restriction on "high density" ram. For 256MB sticks, you must use
a double sided DIMM, with (8) 8Mx8 chips on it. These chips are 64Mbit
technology, and match the limits of chip tech supported by the
Northbridge.

If we go to the Intel web page with datasheets for chipsets, the 440ZX
of the P2-99 is here:

http://developer.intel.com/design/chipsets/datashts/index.htm?iid=PCG+devleftnav&
http://developer.intel.com/design/chipsets/datashts/290650.htm

The Northbridge datasheet says

‹ 8 to 256Mbytes
‹ Supports 2 double-sided DIMMs (4 rows memory)
‹ 64-bit data interface
‹ Unbuffered SDRAM (Synchronous) DRAM Support (x-1-1-1 access @ 66 MHz,
x-1-1-1 access @ 100 MHz)
‹ Enhanced SDRAM Open Page Architecture Support for 16- and
64-Mbit DRAM devices with 2k, 4k and 8k page sizes

It is all too easy to find SDRAM sticks with larger than 64Mbit chips
on it, and the symptoms would be losing part of the total ram.
I'm guessing your problem may be related to this.

Trying one stick at a time, I would expect the 128MB to be recognized by
the BIOS without incident, whereas the 256MB stick will show up as 128MB
in the BIOS, if it is the wrong type (high density). Buying memory from
a site that guarantees it will work with your model of motherboard, is
a good way to get the correct memory. Or, find a vendor with good
pre-sales phone support, who can actually look at a product and verify
it has the right characteristics (i.e. low density 64Mbit chip tech, 16
chips, 8 per side, 256MB capacity). Buying memory from a "web sales only"
web site is asking for trouble (because chances are, they don't know
what they are selling - it is just beans to them).

Just a guess,
Paul
 
I'm sorry I'm still a bit confused.. please bare with me..

The 256 DIMMS that I am trying to use have " 8 chips on each side" a total
of 16 chips.

When you say "For 256MB sticks, you must use
a double sided DIMM, with (8) 8Mx8 chips on it"

Are you saying I need a single 256 DIMM with "4 chips" on each side with a
total of 8 chips?

Thanks
 
"lpender" said:
I'm sorry I'm still a bit confused.. please bare with me..

The 256 DIMMS that I am trying to use have " 8 chips on each side" a total
of 16 chips.

When you say "For 256MB sticks, you must use
a double sided DIMM, with (8) 8Mx8 chips on it"

Are you saying I need a single 256 DIMM with "4 chips" on each side with a
total of 8 chips?

Thanks
Click to expand...

Don't you hate it, when you cannot even do simple arithmetic any more :-(
Oh, well...

Ok, first of all, I have one of the Crucial SDRAM DIMMs in front of
me, and it has a total of 16 chips on it. There are 8 chips on each
side, and each chip is _16Mx8_. (That is _128Mbit_ technology, if
I could do simple math.) 16*16MB gives 256MB.

Maybe the reason these modules work, is they are covered by the
thing in the datasheet about "14x8/9/10 bit addressing modes",
and the 48LC16M8A2 Micron part is 14x10 (the 128Mbit density parts
are 14x9/10/11 bit addressing modes, depending on whether they
are x16, x8, or x4 parts).

http://download.micron.com/pdf/datasheets/dram/sdram/128msdram.pdf

So, I'm _guessing_ that the same lucky accident as the 440BX
applies to the 440ZX, that 16 chips on a DIMM, where each chip is
a 16Mx8 (like the 48LC16M8A2 Micron chips on the module in front
of me) will work. That is what the Crucial.com selection pages
show.

But now, something else is bothering me. Why wouldn't 8 chips of
16Mx16 work on a module ? (So, I download another Micron datasheet.)
Ah, the chips are 15x9/10/11, so the 16Mx16 is 15x9, so one bit
wouldn't be driven on the module, and only half the memory is
detected.

http://download.micron.com/pdf/datasheets/dram/sdram/256MSDRAM_G.pdf

Ok, so back to your problem :-) It sounds like you have the right
kind of module. A 256MB DIMM with 16 chips on it. They have to be
16Mx8 on each chip.

Try that module by itself. See if it behaves. Now, the question
will be, why doesn't it work when the 128MB is there as well ?
That I cannot explain, as the addressing mode should be programmable
per slot. It cannot be a speed problem, because the motherboard
only has two slots, which should work well above PC133.

Is there anything funny about that 128MB module? Maybe you could
describe how many parts and of what type are on that module.

I can tell you that the BIOS on my P2B-S does detect 4 x 256MB of
this memory properly. I don't run it that way right now,
because I am still running Win98SE on the computer.

Paul
 
Paul:

Thanks for your patience. Now I understand what I have, and what I need.
:-)

Peace
 
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