This computer had until today one RAM module of 64MB, which PC Wizard specifies thus:

Manufacturer: Infineon
Part Number : HYS64V8300GU-8ÿÿÿÿ
Serial Number: 0709D96C
Type : SDRAM PC-100 (100 MHz)
Size : 64 MB (1 rows, 4 banks)
Module Buffered : No
Module Registered : No
Module SLi Ready (EPP) : No
Width: 64-bit
Error Correction Capability: No
Max. Burst Length: 8
Refresh: Normal (15.625 µs), Self Refresh
Voltage: LVTTL
Supported Frequencies: 100 MHz, 100 MHz
CAS Latency (tCL): 2 clocks @100 MHz, 3 clocks @100 MHz
RAS to CAS (tRCD): 2 clocks @100 MHz, 2 clocks @100 MHz
RAS Precharge (tRP): 2 clocks @100 MHz, 2 clocks @100 MHz
Cycle Time (tRAS): 5 clocks @100 MHz, 5 clocks @100 MHz

I've added a second module of 256 MB RAM, but Windows isn't seeing it and is telling me that I have only 64 MB RAM. PC Wizard is seeing the new one though, and is specifying it thus:

Manufacturer: Unspecified
Part Number: 32MX64U-100
Serial Number: 010321C2
Type: SDRAM PC-125 (125 MHz)
Size: 256 MB (1 rows, 4 banks)
Module Buffered: No
Module Registered: No
Module SLi Ready (EPP): No
Width: 64-bit
Error Correction Capability: No
Max. Burst Length: 8
Refresh: Reduced (.5x)7.8 µs, Self Refresh
Voltage: LVTTL
Manufacture: 2000
Supported Frequencies: 100 MHz, 125 MHz
CAS Latency (tCL): 2 clocks @100 MHz, 3 clocks @125 MHz
RAS to CAS (tRCD): 2 clocks @100 MHz, 3 clocks @125 MHz
RAS Precharge (tRP): 2 clocks @100 MHz, 3 clocks @125 MHz
Cycle Time (tRAS): 5 clocks @100 MHz, 6 clocks @125 MHz

(NB, the second module was sold to me by PCWorld as being PC100, and is marked PC100 on the card itself. Don't know if this could be the problem.)

Furthermore, the same program is telling me on the Mainboard section that I do indeed have 320 MB RAM:

Mainboard: Gigabyte i810
Chipset: Intel i810
Processor: Intel Celeron @ 400 mHz
Physical memory: 320 MB

but when I click on "Physical Memory" it reports:

General Information :
DIMM1 (RAS 0, RAS 1) : 64 (Single Bank)
DIMM2 : Empty

before going to give me the detailed description of the two memory modules given above!

Any ideas what's going on with the 256 MB module? Does the computer think it's there, or doesn't it? And if it doesn't, is there anything to be done about it?

Thanks!

I suggest you do two things. First read your manual to see what capacity RAM modules can be used. Second, remove the 256MB stick and then go to crucial.com and use the online scan tool to let Crucial determine what kand and how much RAM can be added. Pay attention to ALL the specs on the recommended RAM, not just the capacity. Then compare with the 256MB you bought.

PC100 RAM is supposed to be capable of 125MHz. How it is reported (PC100 or PC125) depends on the SPD info programed into the EEPROM.

Did you try the 256MB stick by itself?

also . how many chips on the 256mb stick. If there are 16 i would have thought OK but if only 8 then i would not be suprised if the motherboard had a problem with ram density. A lot of motherboards from that era cant cope with more than 16mb per chip.
(in my experience)

I'm guessing the maximum per slot may be 128MB.

Thanks for the suggestions guys. The Crucial Memory Advisor tells me that I have 64MB RAM, and also states the following:

# Maximum Memory Capacity: 512MB
# Currently Installed Memory: 64MB
# Available Memory Slots: 1
# Number of Banks: 2
# Dual Channel Support: No
# CPU Manufacturer: GenuineIntel
# CPU Family: Intel Celeron processor Model 6, Stepping 5
# CPU Speed: 400 MHz

Currently installed memory:

64MB, SDRAM, PC100
EMPTY
Each memory slot can hold SDRAM, PC133 with a maximum of 256MB per slot.*

It goes on to tell me, as its first recommendation, that I should instal Part #: CT32M64S4D75 • SDRAM, PC133 • CL=3 • Unbuffered • Non-parity • 133MHz • 3.3V • 32Meg x 64

That looks extremely similar to what I bought, except that it recommends PC133 rather than PC100. This can't be the issue though, since the 64MB that *is* detected is PC100.

Now then, on the other question. If I try the 256MB on its own, the computer beeps when I turn it on and then nothing happens. This is also what happens if I try to boot with the 256MB in Slot 0 and the 64MB in Slot 1, except that the computer beeps twice rather than once - don't know if this means anything.

If I try the 64MB on its own, then it works - whichever slot the module is in. It also works with the 64MB in Slot 0 and the 256MB in Slot 1. This is how I was running earlier when I got PC Wizard to recognise the presence of 320MB RAM (sort of - see first post), but nothing else would.

Oops sorry, missed one of the comments. I've not heard the suggestion that I'd need a 256MB RAM piece with 16 chips on to get it to work before - do others think this likely to be the issue?

And if so, can one actually get 256 MB RAM modules with 16 chips on - I've never seen this fact specified when buying.

Ram that works in another mboard , or any ram you buy or have lying around, may not work properly, or sometimes, not at all - even if it physically fits and is the right overall type (e.g. SDram, DDR, DDR2, etc.; PCxxxx, xxx mhz) for your mboard. In the worst cases of incompatibilty your mboard WILL NOT BOOT with it installed, and the mboard may not even beep - the ram has to be compatible with the mboard and it's chipset.

See response 5 in this for some info about ram compatibilty, and some places where you can find out what will work in your mboard for sure:
http://www.computing.net/hardware/w...
Correction to that:
Mushkin www.mushkin.com

E.g. If this is an older Pbell, it is quite common that ONLY certain 256mb 16 chip (8 on each side; doublesided) ram modules will work in older mboards, and/or for SOME 8 chip modules to work, and usually NO 4 chip 256mb modules will work.
You can often find out for sure on the Kingston web site whether you must use 16 chip 256mb modules if there are listings of modules for your model - the detailed info will often tell you or show you it has 16 chips, 8 on each side.

The ram you have installed will run at the lowest specs of all the modules installed, if applicable. If you leave the 64mb module in, all the ram will run at 100mhz; if the 64mb module has a Cas 3 rating, the other(s) a Cas 2 rating, all the ram will use the slower Cas 3 rating.

The PC125 ram spec was only used for a short time, circa 1999, 2000 - that was bumped up to PC133 after that when faster chips became available, and PC125 ram was after that, and is now, no longer available new. Some utilities, such as CTSPD, can't detect PC125 ram and see it as PC100 ram; some can detect it - e.g. Sysoft Sandra can.

PC wizard must be getting its information from the SPD chip on the ram stick. Although the memory isn't compatible with your chipset (probably because of the density issue already mentioned) the SPD chip is still readable.

The general rule for older systems using SDR-SDRAM is that if the board will not accept 512MB per slot, high density RAM will not be properly recognized. It will either not be recognized at all, recognized at 50% of it's capacity, or it will prevent the system from booting.

This just gets stranger and stranger. First of all PC125 RAM definitely is available new, because I was sold some today - except that it was sold as PC100 RAM!

Now, the Kingston RAM finding tool has analysed my system and told me what I need. It's also shown me a picture of the item they want to sell me - and it has 8 chips. Since everyone seems pretty sure that an 8 chip RAM module isn't going to work, that RAM finding tool has to be dismissed as unreliable.

The Corsair RAM finding tool hasn't heard of my motherboard (GA-6WMM7), so that's no use either.

Mushkin's advisor can see the 256MB RAM module and claims that it's "in use". How can it be if it won't work with this mobo? But Mushkin don't ship outside the USA, so they are no use to me either.

Memory Giant will ship outside the USA but at my risk - i.e. no refund if the shipment never arrives. Somehow I don't think I'll take them up on that.

Sadly, I'm coming to the conclusion that it is not possible to buy RAM that this silly mobo is going to accept. Perhaps I should just do what I came perilously close to doing a few hours back, and throw the box out the window.

Thanks for your suggestions, all the same.

Your best bet is to buy pulled RAM. Your computer is considered obsolete. Therefore many computers of that vintage are just lying around or have been perted out already. A computer shop or reseller of used equipment/ hardware should be more than happy to part with some low density RAM. The supply of that type of RAM exceeds the demand in used RAM. I wouldn't be afraid of buying used RAM from a reputable seller.

BTW, IMO 128MB of additional RAM should suit you if that is what you find. You may even find 2- 128MB sticks for the right price.

You've probably got one of the Intel 440 chipsets on that motherboard which isn't going to work with the higher density chips. A 256 stick with 8 chips on each side might work if the bios will see it as 2-128 sticks, which often happens. Other than that you'll need to look for nothing higher than 128 sticks. They're cheap enough on ebay.

"This just gets stranger and stranger. First of all PC125 RAM definitely is available new, because I was sold some today - except that it was sold as PC100 RAM!"

Why is that strange? As I stated earlier, PC100 is supposed to be capable of 125MHz, it's part of the PC100 spec:

"Memory that conforms to the complete Intel version 1.0 pc100 specification is called full compliance pc100 memory and can function reliably at full speed, that is at the 100 MHz bus speed. The theoretical limit quoted for this memory is 125 MHz"

http://www.pc100.com/

"A SDRAM chip that internally clocks at 125MHz is necessary to sustain a 100MHz local Bus speed. It is important for consumers to closely analyze SDRAM offerings, especially those that are "to good to be true", to ensure PC100 compliance. Since it is not easy to verify PC100 compliance, purchasers are well advised to do at least two things, (A) buy PC100 SDRAM modules that only use 125MHz or 8 nanosecond parts, and (B) only purchase modules manufactured by a reputable supplier willing and able to meet the PC100 specification"

http://www.dewassoc.com/performance...

Hard to believe any Memory scanner missed your MOBO. First item on google search.

http://www.active-hardware.com/engl...

Pulled ram should be fairly easy to find for your Box. I may have some available.

There is nothing to learn from someone who already agrees with you.

Using your stated GA-6WMM7 mboard model.....

You definately need one with 16 chips, and Kingston shows you the 256mb module has 16 chips here:
http://www.valueram.com/datasheets/...
(the Data Sheet)

You can get Kingston ram just about anywhere in the world. Search the web using the module ID string to find a place nearer you that has that module, or check out local places, which often have web sites, that have Kingston ram - I know some local places near me have this module.