How does Windows see more Ram than the BIOS?

Zepher

[H]ipster Replacement
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I got an older machine from a client, one that I built for them 11 or so years ago.
It has this board https://www.gigabyte.com/Motherboard/GA-G31M-ES2L-rev-24#ov
along with a Core2Duo E6400 and 2x 1GB DDR2.

I went ahead and flashed the BIOS and installed a Core2Duo E8600 I had lying around as well as a pair of 4GB DDR Dimms I bought last year to try and upgrade my modded E5460 Xeon 775 system to 16GB.
Those 4GB sticks didn't work in the Xeon or an AMD system I had so I just bagged them up and stuck them in a drawer.

I stuck the ram in and the machine actually posted and showed 4GB of ram in BIOS. I then pulled out one since the board is supposed to only support 4GB of total ram but it showed as 2GB in BIOS with one of the 4GB sticks installed.
I went ahead and put the second stick back in and installed Windows 10 on the machine. I went and looked at the Windows properties and it shows the E8600 and 8GB of ram with 4GB usable.
Rebooted the machine, checked BIOS and it shows 4GB installed, go back to Windows and it shows 8GB installed with 4GB usable. Went to msconfig and set the max ram to 8GB, rebooted, BIOS still shows 4GB,
and Windows still shows 8GB installed and 4GB usable.

Since Windows somehow knows that there is 8GB installed, how does one get the system to use it all?


e8600-01.jpg


e8600-02.jpg
e8600-03.jpg
 
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bios mobo only supports 2 GB per slot so it only uses 4GB total. the ram sticks are reporting they are 4GB each so windows sees 8GB total but only 4GB usable. maybe.
 
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Have you tried other ram or other slots?

Sounds like the sticks maybe defective. Not defective enough that Win10 can't pull the information on them, but defective enough to not be able to use all the chips.


Seems other folk have had similar issues.
https://forums.tomshardware.com/thr...2gb-total-in-bios-windows-and-ubuntu.2239773/

https://webcache.googleusercontent....03072944766/?l=thai+&cd=6&hl=en&ct=clnk&gl=us[/URL]

I forgot to mention that the motherboard officially supports only 4GB of total system ram. I got a phone call while I was typing the OP and lost my train of thought.
 
Oh.. then there ya go. The ram can report what ever number it is, but if the board doesn't recognize it then you are knee capped.
 
Oh.. then there ya go. The ram can report what ever number it is, but if the board doesn't recognize it then you are knee capped.
I am just wondering how Windows can see that I have 8GB installed when the BIOS shows 4GB. I figured Windows gets its info from the motherboard's BIOS.
 
yeah, what he said^^ thats what i meant by "ram sticks are reporting they are 4GB"
 
At least it isnt like the old days when you put more memory than supported the board wouldnt even post. Like the time I put an extra 256 MB in my Asus intel 815 board....512MB was the cap.
 
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