RAM question: help!

[Daniel Walters]

Hi all,

If anyone can help I'll be eternally grateful,

Basically, I'm trying to add some RAM to my old crap PC (bought in 1998 - a
Cyrix 6x86 M2 300Mhz with 32 MB RAM, 4 MB of which is used for onboard
graphics - dunno what motherboard model it is though).

I went to buy a 256 MB DIMM (PC133) for the spare slot, but the PC only
recognised 128 MB of it (plus the other 28 MB, so 156 MB total)

I presumed that meant my motherboard's memory slots could only take 128 MB
max each, so went back to the shop and replaced my 256 MB DIMM for two 128
MB ones... but after slotting them in, the PC only recognised 64 MB of each
DIMM, so 128 MB total (minus 4 MB for the graphics...)

So my PC only seems to recognise half of *whatever* you put in (except for
the original 32 MB, apparently?) aaaargh.... dunno if i need to change a
jumper switch somewhere on the mainboard, or fiddle about with BIOS, but
thought best not to mess around without even knowing what model it is! (the
manual is back with relatives 250 miles away... and they're on holiday for 3
weeks!)

Subsequently found that my existing 32 MB RAM was ECC SDRAM (which I found
out by doing a Google search for 'MDV323S-28', printed on a sticker on the
DIMM). Don't think this RAM I've just bought is (there was memory labelled
'Registered ECC PC133', but that was twice as much!) - could this be the
source of my problems, do you think?

Cheers in advance!

 

[S.Heenan]

Hi all,

If anyone can help I'll be eternally grateful,

Basically, I'm trying to add some RAM to my old crap PC (bought in 1998 - a
Cyrix 6x86 M2 300Mhz with 32 MB RAM, 4 MB of which is used for onboard
graphics - dunno what motherboard model it is though).

I went to buy a 256 MB DIMM (PC133) for the spare slot, but the PC only
recognised 128 MB of it (plus the other 28 MB, so 156 MB total)

I presumed that meant my motherboard's memory slots could only take 128 MB
max each, so went back to the shop and replaced my 256 MB DIMM for two 128
MB ones... but after slotting them in, the PC only recognised 64 MB of each
DIMM, so 128 MB total (minus 4 MB for the graphics...)

So my PC only seems to recognise half of *whatever* you put in (except for
the original 32 MB, apparently?) aaaargh.... dunno if i need to change a
jumper switch somewhere on the mainboard, or fiddle about with BIOS, but
thought best not to mess around without even knowing what model it is! (the
manual is back with relatives 250 miles away... and they're on holiday for 3
weeks!)

Subsequently found that my existing 32 MB RAM was ECC SDRAM (which I found
out by doing a Google search for 'MDV323S-28', printed on a sticker on the
DIMM). Don't think this RAM I've just bought is (there was memory labelled
'Registered ECC PC133', but that was twice as much!) - could this be the
source of my problems, do you think?

Two issues. 1) Newer RAM is more dense than the older variety of 1998. Older
chipsets can only see half on the installed RAM. ECC is a particular type of
SDRAM normally used in servers. Mixing ECC and non-ECC RAM will not work.
You can likely disable the ECC feature in the BIOS and use unbuffered
non-ECC PC100 SDRAM.

If you know the maker of your PC or better, the name and brand of the
motherboard, you can use the Crucial memory selector to find the correct
module. http://www.crucial.com/uk/index.asp

 

[Norm]

Dan, I had a similar problem when trying to increase the memory of my
sister's Emachine. While any 128mb stick would use all 128mb the 256 stick
would only show up as 128mb. After a little trial and error I found that if
you install double sided memory sticks it would work fine. Both Emachine
and Crucial say you can only use 2 128mb cards but I installed 2 256mb
double sided sticks and have it running at 512mb with no problems at all.