RAM problem
Author
Discussion

chrisrwc

Original Poster:

60 posts

250 months

Wednesday 24th January 2007
quotequote all
I've just got 2G of ram for my computer, it originally had 1 so should have 3 now, I've checked that each ram card is working properly and they are, but I'm only getting the 2G of new ram on my system, yet when I use crucials system scan it shows that all 4 cards of ram is in place. Anyone know why this isn't working?

Fidgits

17,202 posts

260 months

Wednesday 24th January 2007
quotequote all
they are balanced right?

you havent put 2 1 gig DDR400's next to 2 512Meg PC100's have you?

ThePassenger

6,962 posts

266 months

Wednesday 24th January 2007
quotequote all
Fidgits said:
they are balanced right?

you havent put 2 1 gig DDR400's next to 2 512Meg PC100's have you?


PC-100's won't fit in a DDR slot (I think DDR2's will fit in a DDR slot though), but it could be a mismatch however do you have the manual for the motherboard? Or know it's model number (if it's something like a Dell Dimension xxxx google that)? It could be that the motherboard is only capable of supporting 2GB of RAM.

chrisrwc

Original Poster:

60 posts

250 months

Wednesday 24th January 2007
quotequote all
Cheers hadn't even thought of that Ive now got 1,512,1,512 but now showing 2.18G of ram, the mother board should in theory support 4Gig of ram.

ThePassenger

6,962 posts

266 months

Wednesday 24th January 2007
quotequote all
chrisrwc said:
Cheers hadn't even thought of that Ive now got 1,512,1,512 but now showing 2.18G of ram, the mother board should in theory support 4Gig of ram.


But it might only support certain 'valid' configurations... (1,1,1,1 or 2,2,0,0, or 512,512,512,512 and so on). Annoyance: these valid modes can change from chipset to chipset and BIOS revision to BIOS revision. Hence taking a peek at the manual, it might have something in it that reads "Disabling Dual Channel mode for none supported memory configurations" or words to that effect.

momentofmadness

2,371 posts

272 months

Wednesday 24th January 2007
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Sometimes memory seems to be a bit of a black art (to me at least!). Try swapping them around and you may be suprised

twister

1,593 posts

267 months

Wednesday 24th January 2007
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Is it the BIOS telling you there's only 2GB, or the operating system?

chrisrwc

Original Poster:

60 posts

250 months

Wednesday 24th January 2007
quotequote all
Thanks for all the help it's an Asus A8N-VM Motherboard, but I can't seem to find the right configuration, or which BIOS setting I need to change, it's now running at 2.25Gig which seems a bit weird to me in 1,512,1,512

PJ S

10,842 posts

258 months

Wednesday 24th January 2007
quotequote all
Is all your RAM DDR400 (PC3200)?
If so, then what's the initial POST display as being checked?
You may have to put one stick in at a time to check the RAM is actually detected and showing as it should.
Are you overclocking the RAM - timing or FSB multiplier?
Single module RAM - use the second blue slot for testing all modules report size and speed correctly.
Dual channel (pairs) - use blue and check speed and size reported
Try one RAM in the first black slot with the two blue ones filled - see what's reported.
Swap and try the second black slot and see what's reported.
There could be a problem with one of the RAM slots and this is why it's not detecting all 4 slots filled with the correct tally.
There's a bit of trial and error for you to do, before you come to that conclusion though.


Edited by PJ S on Wednesday 24th January 20:31

chrisrwc

Original Poster:

60 posts

250 months

Wednesday 24th January 2007
quotequote all
Cheers in the POST message it is comming up with 3000MB but not in windows, tried one config and computer just wouldn't start just kept booting up but not get to windows loading screen which is a bit odd. I think I might not be able to do anything about it and I'm not overclocking it.

Thanks for all the help.

ThePassenger

6,962 posts

266 months

Wednesday 24th January 2007
quotequote all
Dumb question to those with more experience of such things. Can Windows report 3GB ram?

jimmyjimjim

8,332 posts

269 months

Wednesday 24th January 2007
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Yes.
More likely to be a BIOS limitation though. My Asus A8N Sli will support 4 1Gb DIMMs, but BIOS limitations mean that if I plug these in, it can only actually address the first 3 or 3.5Gb, the remaining address space being used to control other device such as HDD controllers and video cards. IIRC this is a limitation of the original PC spec. But I could be on crack.
The 3/3.5Gb limitation is true though, at least for my mobo; read the manual carefully, it might be less in this case depending on the chipset in use.

edited to add - windows is probably getting pissy when it tries to access the 3 Gb of RAM that the motherboard reports, but can't really access. I'd pull the original 2 512Mb stick and see what happens.


Edited by jimmyjimjim on Wednesday 24th January 21:58

malman

2,258 posts

290 months

Thursday 25th January 2007
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ThePassenger said:
Dumb question to those with more experience of such things. Can Windows report 3GB ram?


Windows can quote all kind of figures when you get past 2Gb type 3Gb xp and 4Gb xp in the knowledge base

malman

2,258 posts

290 months

Thursday 25th January 2007
quotequote all
jimmyjimjim said:

IIRC this is a limitation of the original PC spec. But I could be on crack.


Edited by jimmyjimjim on Wednesday 24th January 21:58


The 4Gb limit is the max a 32bit proc can natively address. 64bit can support huge amounts of ram (xp64 limited to 128Gb by M$ at the moment I beleive) unfortunately motherboard chipsets sometimes don't so you are still limited to 4Gb