[Problem] GA-8I945P-G-RH uses only 2.6 of 4GB RAM


I have an old GIGABYTE GA-8I945P-G-RH, for which I buyed 4x1G “ELPIDA 2Rx8 PC2-5300U-555” DIMMs. All the units works, and all the sockets too (I have tested one by one in every socket). The MoBo support dual channel for DDR2 667MHz DIMMs

When I install the 4 DIMM, the MoBo only recognize 2.6GB (Windows 7 sees the 4GB, but only 2.5 are usable). No way to get the 4GB changing the position og the DIMM in the socket.

Reading and reading in the net, the only I have seen is that these old MoBos use part og the RAM installed for the internal GPU and abother peripheals (?)… I do not know if this is true or not, but if it uses 1.5GB of 4GB for other purpouses than the RAM I have done a bad business buying this RAM

My BIOS do not have the option to disable the internal GPU (I have installed the last version offered in GIGABITE’s page, F4). I know that in this BIOS you can access to hidden options by CTRL+F1, but there is not that option either.

Is there some kind of solution for the BIOS recognicing the 4GB? Or is it impossible in this MoBo?

Thanks in advance

Edit by Fernando: Thread moved into the “BIOS Problems” Sub-Forum and thread title customized/specified


AFAIK this is true.
Maybe a BIOS modification can solve the problem, but I am not an expert regarding this topic.

Thanks Fernando,

If you are almost sure that it is true, it must be true… and that is my perdition :wink:

Some caritative soul reading this thread, can give any solution, or link to a modded BIOS? Maybe there is a compatible BIOS from another MoBo

The main problem here is being an old AWARD 6.0 bios generation… a bit tricky to mod since AWARD tool sees the setup/strings but doesn’t identify it correctly.
MODBIN is not viable here and CBROM also not useful besides module handle if needed.
This is your starting point for further research to the subject, if any solution possible at all…
You should wait for another user opinion.
Good luck

Thanks @MeatWar

I have any idea of modding BIOS, so I’m afraid I would have to make up with my 2.5GB

Yes, you can install the OS and work with the PC until the problem has been solved. You don’t need to re-start from scratch after having flashed the modded BIOS.

Thanks Fernando, It seems to be my only possibiity


Post a screenshot with Mainboard tab of CPU-Z.

And open Device Manager, click View at the top of the Device Manager window, click Resources by type, and then select Memory. This should give you an output similar to the picture shown below


Which Windows 7? 32 or 64 Bits?

You are hitting the once famous PCI Memory Hole: https://en.wikipedia.org/wiki/PCI_hole

You may be able to see more RAM by disabling PCI Devices that could reserve MMIO. But don’t expect to actually see all the 4 GB worth of RAM in 32 Bits OSes unless you’re using PAE (Physical Address Extensions). And there were some Intel Chipsets of that era (Or a bit earlier) that didn’t actually implemented a 36 Bits Physical Address Bus for proper PAE usage, only 32, so you were limited to 4 GB in total for both RAM + MMIO anyways.

I’m a bit lost with all this

@DeathBringer , I will tray to do it this weekend, thanks.

@zir_blazer I am on W7 32 Bits, baut the MoBo is 64 Bits. I thought to install W10 64 Bits after buying the new 4 GB RAM, but with my actual 2.5 GB I prefer to remain in W7.

Could I get something better installing W10 64 Bits?

Thanks to both

There is no such thing as 64 Bits Motherboard.

Install Windows 7 64 Bits and check again how much RAM is detects. You don’t need Windows 10, just a 64 Bits OS (Or 32 Bits + PAE, which on Windows wasn’t straightforward due to Driver issues). You could even try with a Linux LiveCD that supports both 64 Bits and BIOS Boot.

Thanks @zir_blazer . Right now my Win 7 detects 4 GB, but only 2.5 are usable (in the System windows in Control Panel)

@DeathBringer , I upload the photos you asked for

@Haplo , look at your screenshots.
Your system uses 945P with 32bit’s PAE. So it can’t address memory above 4GB.
In your system memory above 0xA0000000 address is used by internal devices. So only 2560 Mb are available. It can’t be changed by any BIOS patches, but you can try to use a graphics card with less memory.


What do you mean with a graphic with less memory? To change the Nvidia Gforce 210 with another worst Graphic? What can I get with this?

It is LGA775 socket, There is any Pentium D for this socket supporting PAE 36 Bits?

Thanks for all

Yes, you need worst graphics card for the test.
All motherboards with LGA775 have a memory controller in the chipset, not in CPU.

So ther is nothing to do… :pensive: . I’ll give it a try to change the graphic.