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I have the following machine configuration:
In both Windows and the BIOS I have 3.25GB memory available. How can I enable it to support 4GB?
EDIT: I've sort of upgraded the CMOS version, and Windows acknowledges I have 4GB but is only using 3.25GB.
I guess it is hardware after all?
ArielBH
Posted 2009-09-04T08:51:42.883
Reputation: 185
16
Your BIOS needs to support memory hole remapping.
Memory hole is there since all devices must fit in 32-bit address space during boot (since BIOS is not aware whether you will use 32-bit or 64-bit OS later). Remapping takes care to move affected memory to memory area after 32-bit boundary.
I would check whether new BIOS firmware is available if that setting is not in your current BIOS firmware.
Josip Medved
Posted 2009-09-04T08:51:42.883
Reputation: 8 582
Yes, there is a newer firmware version. Right now I've F2 installed. I will try to update, right? bit.ly/M0Fgv – ArielBH – 2009-09-04T09:25:41.910
1@ArielBH: yes, update is almost always a good thing. – Josip Medved – 2009-09-04T10:11:32.660
1Strangest thing. I tried to update the CMOS. I did every step by the book. The cmos failed to load. I had to clear the CMOS. CMOS is up again, and now when I check the version, it indicate the new version, how can it be? – ArielBH – 2009-09-04T13:34:05.003
1@ArielBH: It is definitely strange. I would try to update it once more just to check whether it updated everything. Most BIOS update routines check whether old BIOS fits ok. – Josip Medved – 2009-09-04T15:54:09.513
2@josip frankly I feel lucky that I've managed to get the cmos to work again. I think I will not touch it anymore :) – ArielBH – 2009-09-04T21:33:15.227
4
Rodney Schuler
Posted 2009-09-04T08:51:42.883
Reputation: 1 189
2
Windows 7 x64 should recognize that RAM with no fiddling required.
If the BIOS doesn't recognize all 4 GB, there's no chance Windows will see it. It's possible that the reason they provide a memory support list is because the board is very choosy.
I would each of your ram sticks individually, to make sure the BIOS sees them correctly.
Now that I'm thinking about it, the SU guys are going to have a lot more experience with this.
Kara Marfia
Posted 2009-09-04T08:51:42.883
Reputation: 2 000
1Josip is probably right - did you find any options related to memory hole remapping in the bios? – Kara Marfia – 2009-09-04T12:54:09.157
2
It looks like the 945 chip set doesn't support more than 4 GB of address space (and some versions only 2GB). So you end up with the same limitation as Vista 32 bit - you won't be able to use all of 4 GB of your RAM since address space is used for more than just RAM.
From the Intel 945 chip set datasheet page 24:
The (G)MCH supports 32-bit host addressing, decoding up to 4 GB (2 GB for the 82945PL/82945GC/82945GZ) of the processor’s usable memory address space
And of page 205:
Addressing of memory ranges larger than 4 GB (2 GB for 82945GC/82945GZ/82945PL) is not supported
shf301
Posted 2009-09-04T08:51:42.883
Reputation: 7 582
0
The manual for your motherboard doesn't say it is a requirement, but it does advise using the same size memory modules. It's possible that having 1gb modules being scanned first is preventing it from detecting the larger 2gb module.
I would try swapping which bank the modules are in ( 1x2gb <-> 2x1gb ) and see if that helps, failing that I think you just need to get two 1gb modules to replace your existing 2gb module.
Of course, the up-side of the latter would be that you'd re-enable dual-channel and get faster memory use of the system.
ted_j
Posted 2009-09-04T08:51:42.883
Reputation: 151
Yes, I had those 2*1GB chips. My last visit to Redmond, USA i've bought 2 chips of 2GB. As it happens one of them was faulty, so I got stuck with only one (and I live abroad USA). – ArielBH – 2009-09-04T13:43:22.857
Yeah--I would never mix memory chips like that. It's not the culprit but it's just asking for trouble. – Loren Pechtel – 2009-09-04T15:48:36.483
I'm fighting the same battle right now. Pretty sure we're hosed with the i945 chipset. Granted, I'd love to be proven wrong!
– Chris_K – 2009-09-04T13:18:53.523