4Gb RAM

[MrRobin]

I recently purchased another couple of sticks of 1Gb memory to upgrade my desktop to 4Gb. There are 4 slots on the mobo and I now have 2 matched pairs, but when all 4 are installed, the PC won't boot.

After some googling, I read that it is necessary to enable the options in the BIOS for memory remapping to get the thing to recognise there is 4gb present. In my BIOS, one option is for software remapping and one is for hardware remapping. I have tried all the combinations of switching one on and one off, both on etc. One combination (S/W on, H/W off I think) gets me to Windows but it just promptly freezes up.

Do I need to change anything else, like the CAS timings or the voltages etc? Anything from the OS side?

P.S. When I use either pair of sticks on their own, there are no problems so I don't think there is a problem with the RAM itself. The mobo definitely supports up to 4Gb. I have Win XP x64 edition so the OS can support that amount too.

TIA

[KevinS]

Have you checked the mobo manufacturers website for a possible BIOS upgrade? Does the machine boot with either (2GB) pair?

[PAH]

Does the machine boot at all (i.e. initial bios checks, beeps etc)? If not powering up maybe the PSU is overloaded.

Other thing to try (if your mobo/memory config allows) is to only try 3gb instead of 4gb. May be a bios update is needed or there are issues with using the max ram if not all 100% the same type/speed etc.

Another thing to consider is that some versions of Windows (not sure about the 64-bit ones) only allow 4gb max including video card ram. So if you've a 1gb video card, you'll only be able to use 3gb system ram, due to the way the memory addressing is done. Shouldn't stop it booting up though.

[MrRobin]

Thanks for replies so far. Yes I have the latest BIOS, and yes it boots up with either of the pairs on their own. The RAM is same type (DDR PC3200) same manufacturer and same speed etc. Only difference is that one pair is 2 years newer than the other and has a slightly different heat spreader on it.

It will post and make all the usual beeps and display the usual stuff at boot, including the memory count (correctly counts 4Gb) but will either reset itself just before getting to the windows loading bit (with the green scrolly progress bar) or will get to the desktop but then freezes up.

I will try 3Gb a bit later and see what happens

I have 2 x 256Mb gfx cards but yeah like you said it should still boot.

[scorchio]

You might want to take a look at these(especially the /3GB part)

http://support.microsoft.com/kb/833721

http://technet2.microsoft.com/window....mspx?mfr=true

[skelm]

Dunno if this helps but you could try it out.

You'll have to boot with 2GB then install the update and re-install the extra 2GB.

http://support.microsoft.com/kb/929777


HTH

[wc2]

Just a possibility but....

Are the slots different colours?

i.e. black / blue / black / blue

If so then you may be only able to use 2 at a time blue or black, it’s been a while since my hardware days (I think they are for different speeds)