Compaq Presario new RAM "164 - Memory Size Error"

I have attempted to upgrade the RAM in a Compaq Presario desktop PC, and am made aware of a POST message code that appears right near the start of POST.

The system boots OK with the single 64MB stick of PC100 memory, but fails to get past POST with 2 x 256MB PC133 memory.

The error message "164 Memory Size Error" shows regardless which memory is installed, but it's just that the hang at POST with the new memory allows me to see this on screen.

States that a "164 - Memory Size Error" should be accompanied by 2 x short beeps and identifies the cause as "Memory Config Incorrect", and suggests "Run Computer Setup".  There are no beeps, but I forgot to check the internal speaker connection, and I seem to recall that it doesn't give the "started OK" single beep, so it probably is beeping at me., however, state this in their FAQ (
Q: When I installed my memory my computer displayed a "164 memory size error."

A: Don't worry about it. Some computers show this message whenever memory is added or removed. There is no cause for concern, and the message will disappear the next time you boot up your system.

The problem is that this F10 CMOS Setup Screen doesn't have any memory-specific settings to change.  I will need to look into this further, and perhaps see if it is running the CMOS Setup from a non-DOS F10 diagnostics partition as with some of the older Compaq's.

When I change the memory back and forth, the BIOS DOES detect the change, and counts through it up to the correct RAM capacity (minus the 1MB of shared video memory - it also has a whopping 4MB on-board video memory all to itself!!).

Compaq Presario 5BW120 Desktop PC - Product Specifications:

Intel i810e Motherboard Memory Spec's:

2 x memory slots - use one or both with SDRAM
Min 16MB (i810 board needs 64 MB due to on-board graphics)
Max 512MB
Type 3.3 v 168 pin SDRAM DIMM 100 MHz unbuffered non-ECC (64-bit)
SPD (Serial Presence Detect) (BIOS recovery needs SPD).

Supports Single or Double-Sided DIMM's in the following sizes:

16MB  -  2 Mbit x 64
32MB  -  4 Mbit x 64
64MB  -  8 Mbit x 64
128MB - 16 Mbit x 64
256MB - 32 Mbit x 64

Note: If using 256MB modules, they must be built with 128 Mbit technology.

Crucial's Online Memory Configurator showed this as one of the compatible modules:

256MB CT283169 SDRAM, PC133 CL=2 Unbuffered Non-parity 3.3V 32Meg x 64

So the 133 MHz really isn't an issue here but I'm puzzled about the note in the Intel i810e pdf manual about the "128 Mbit technology" requirement for 256 MB modules indicated above.

Any idea what they mean by that?

The single SDRAM DIMM that WAS fitted before, and with which the system booted OK but still showed that "164 memory Size Error at early POST, was:

Micron Tech. 4LSDT864AG-10EB1
64MB unbuffered 64-bit non-ECC PC100 SDRAM

The 2 x 256 MB modules I have fitted, and on which the boot halts at POST, are the same spec (as far as I am aware), except the speed.  They are a couple of modules branded for a large computing outlet based in the UK, but I don't have them with me to check the number of chips, etc.

Of course, the notes above about what RAM is accepted is taken from the INTEL documentation relating to an Intel branded i810e board, and not the Compaq one used in the Presario 5BW120 C/600/E model.  This falls into the Presario 5000 Series, but the motherboard is reported by diagnostics utilities as Whitney 910e just the same.

The Compaq motherboard model is 06C0h, and the current BIOS version and date are Compaq (07/24/00) version 686C3.

The latest Compaq BIOS update would upgrade it to 2001-07-20 (1.05 Rev. A), but the list of fixes in that (and included from previous versions) does not address any issues about memory.

The only useful features, for which I am tempted to flash the BIOS, are:

- Added F10 Setup Detect Drive feature for IDE and floppy drives
- Enhanced USB legacy handoffs
- Improved USB support in DOS and Windows safe mode
- Enhanced boot options in BIOS setup
- Changes memory buffer strength for configurations of two double sized memory modules

Do you think that last fix might be relevant?

The 2 x 256MB modules I am trying to use in the system are double-sided, but I'm not sure that I understand the "memory buffer strength" expression.

Running the Microsoft Memory Diagnostics utility from boot CD seems to freeze indefinitely after about the 3rd test of 7, which tends to imply  faulty memory, but I would have thought this would have issued a different error code like: 201 or 203 - Memory Address Error (RAM Failure Replace Memory) as listed here:
A "parity error" would also issue a different code.

I intend to test the memory on my own PC (Pentium 4 board), but can only get back to the PC in a couple of days.

Any suggestions or comments will be appreciated meantime.
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nobusConnect With a Mentor Commented:
if you find single density sticks, there is a fair chance that they might work.
You can also ask what benefits you will have from a bios upgrade from a specialised company like :

most of the time, they will specify exactly what the benefits will be; but i doubt they can change the ability to use double density instead of single density
well, the only thing i know is that Compaq's are picky about the memory they use. I always use kingston memory for them.Or you can buy the same brand.
What is possible also, is that it will only read half of the size, if it does not support double density memory.
i would not start right away changing settings in the bios, unless you know which ones, and note them.
it can also be that it does not accept a mix of those sticks.
So i suggest :
1- use the same brand if you use more than one stick
2-try using one stick
MrBillisMeConnect With a Mentor Commented:
I would recommend adding only one additional 64MB PC100 DIMM since Windows98 is not going to benifit from anything more than 128MB, infact in some machines too much RAM will actually slow them down. It seems the board has a limitation regarding RAM so it just better to to stick to the original specification.
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BillDLAuthor Commented:
Thank you both.

The board's limit is 512MB and the max DIMM capacity for each of the two slots is 256MB.

I notice a distinct improvement from 128MB to 384MB or RAM with Windows 98 in most PC's, but the benefits from 384 to 512MB are less obvious.  In some cases, there may appear to be little or no benefit from 384 to 512MB, but only having two slots is a nuisance so I went for the 2 x 256MB matched sticks.

It is still freezing at boot with only 1 x 256MB stick in slot No. 1.

I didn't have spare memory modules with me, but that is something that I WILL try in a couple of days when I get back to the machine, and I have meantime emailed the vendor to verify the exact specifications re ECC/non-ECC, Parity/non-Parity, etc.

Any idea what the BIOS update notes mean when they say "memory buffer strength"?

I will update as soon as I get my hands on the machine again and try some other RAM.
gonzal13Connect With a Mentor RetiredCommented:
From Google  Memory buffer strength
Details and datasheet on part: 82815
... 68 3.4.24 BUFF_SC--System Memory Buffer Strength Control Register (Device 0)....
69 3.4.25 BUFF_SC2--System Memory Buffer Strength Control Register 2 ... parts/datasheet/227/82815.php - Similar pages

Details and datasheet on part: 82371AB
... 3-24 3.3.20 MBSC--Memory Buffer Strength Control Register (Device 0)......3-25
Register Description.........3-1 3.2 3.3 82443ZX Host Bridge Datasheet ... parts/datasheet/227/82371AB.php - Similar pages
Interestingly enough, using the same text on altavista and then on a website, it refers to memory installed. Did you check your memory?
BillDLAuthor Commented:
Thank you all.

Firstly, gonzal13's links led me to look at the pages relating to memory controllers, etc.

Intel® 810E Chipset: 82810E Graphics and Memory Controller Hub (GMCH) Datasheet

On page 47 of, it provides an explanation (with respect to programming) of the expression "System Memory Buffer Strength".

I also found the following question and answer that describes similar problems and references the BIOS update fix that I spotted and thought might be relevant.

That said, however, here's the latest.

The damned thing eventually recognised the new memory apparently by itself and booted into Windows!!!  It seems to be running Windows fine and without any glitches.  It also passed all memory tests.  The increase in speed of Internet page loading and application access is as expected - very slick.

Now, what I don't understand is WHY this finally just decided to work.  I swapped the memory back to the old 1 x 64MB PC100 SDRAM, and booted perfectly.  The BIOS detects the change and counts through the memory correctly, and issues the same "164 - Memory Size Error", but then resumes normally back to its sluggish old self again.

I had 1 x 128MB PC133 SDRAM (double-sided like the new 256MB ones) and decided to give that a go on its own.  Again, the change was detected by the BIOS as it counted through the new capacity, issued the same 164 message, then booted perfectly into Windows which showed a reasonable speed improvement.  I rebooted to the memory test, and it sailed through.

I had packed the 2 x 256MB PC133 SDRAM modules back into their box intending to take them home and test in my own machine, but decided to have a go with them one last time.  Bang, instantly recognised and registered as 512MB and, despite that same old 164 message, booted right into Windows at blistering speed.  I just looked blankly at the owner like some kind of dumb ass as he said "well done, what did you do to fix it?".  I can't recall what I muttered, but shrouded it in techno-babble to disguise my befuddlement :-)

All I can think of are 3 possible reasons:

1. Seating and reseating the different memory has polished the contacts and/or shifted dust.  I would have thought that either cause would have issued a different error though.

2. The intermediate step of a single PC133 double-sided module has somehow been recognised and automatically configured to form an intermediate step that allowed the BIOS to then take the next step.  Remember that this CMOS setup is so limited that it affords virtually no user settings, but is certainly able to auto-detect new IDE devices.

3. Upgrading the CD-RW at the same time as the memory has given it too much to think about and, had I sat and waited for a lot longer, perhaps it would eventually have accepted the memory OK.  I once sat for about 20 minutes while a much older Compaq Deskpro 2000 auto-detected and configured a new hard drive!!

Who knows, but computers are mysterious and annoying beasts and this one had me about to smash it to bits.  The BIOS update is no longer a consideration, thank goodness.

So, to wrap up, thank you all for your input.

Regards Bill
BillDLAuthor Commented:
Whoops, forgot to paste the link when I mentioned that I had found a Q & A forum with similar issues:
Thanks for poinx...............some times these things are just freaky and unexplainable. About the time you think you know what happened some thing else will prove that was not the reason.
BillDLAuthor Commented:
Yeah, I know.  I'm just waiting on the phone call to tell me so...  :-)

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