Memory 8GB installed bios sees 4GB

[Bugler101]

New Motherboard ASUS M5A78L-M LX PLUS, bios version 1302 windows 7 Ultimate 64 bit, video ATI Radeon HD 5450. I have installed 8gb of memory and bios reports only 4gb, windows sees 8gb with 4gb usable. I have tried all the usual fixes, updated bios, swapped sticks ( reseated ) install 1 stick at a time to no avail. I can not seem to find any memory remapping switches in bios setup, but something is locking out 2nd 4gb. Any suggestions????

 

[johnbl]

I don't know if this helps but it kind of sounds like the motherboard DMI pool was not updated when the memory was first added and was never refreshed. To fix you have to trigger the BIOS to flush its pool and build another database. Often you can do this by making a hardware change, such as moving a hard drive cable to another port, disable some hardware and then re-enable it. Be sure to select plug and play OS in the bios if you have that setting. Some BIOSs will have options to rebuild the DMI pool, some have utilities you can run. bugs in BIOS versions also prevent proper hardware detection.

- you know that the BIOS plans to build a new DMI pool if you make a change and tell the system to reboot. if the BIOS has to build a new DMI pool, it should force a shutdown that acts like a cold boot rather than a warm boot.

-you could also have a physical problem with the interleave controller in your CPU or where it connect into the CPU socket.

- you could also reduce your memory speed and see if both RAM sticks are correctly detected. Each stick of RAM will cause a capacitance induced timing delay in the circuit. you can have both sticks individually run at 1600MHz in either slot but fail when both slots are in use. (generally, the timing is close, it works while the circuit is cool and fails during use later) low probability of this error in this case but check the lower speed just in case)

- first step would be to get your BIOS to work correctly without involving the OS.
- maybe have your BIOS do full tests rather than the default quick boot tests and see if that detects and updates your memory count in the BIOS

EDIT
- since you can run windows, try and download and run CPUID CPU-z program and
have a look a look of how it reads your memory bank configurations and see if they are as you expect or have set in your BIOS

 

[Bugler101]

My settings are as follows:
Bank Interleaving <auto>
Node Interleaving <auto>
Channel Interleaving <auto>
Memory Hole Remapping <Enabled>
Power Down Enable <Disabled>

Internal Graphics: Set as indicated

Primary Video Controller <GFX0>
UMA Frame Buffer Size <auto>
Frame Buffer Location <Above 4G>

I have a jumper which clears/resets bios and I did that to force a rescan.

NO JOY

 

[ex_bubblehead]

My settings are as follows:
Bank Interleaving <auto>
Node Interleaving <auto>
Channel Interleaving <auto>
Memory Hole Remapping <Enabled>
Power Down Enable <Disabled>

Internal Graphics: Set as indicated

Primary Video Controller <GFX0>
UMA Frame Buffer Size <auto>
Frame Buffer Location <Above 4G>

I have a jumper which clears/resets bios and I did that to force a rescan.

NO JOY

Reread what I posted above and set as I indicated.

 

[Bugler101]

set as you posted. NO JOY..... Also I have 2 other settings which no one has told me to set. They are Dram Controller : DCT Unganged mode and is set to Always.
and under Internal Graphics: Surround View and set to Auto. Surround view has to do with the ATI graphics card in the PCie x16 slot, But I don't know what it does. the options are auto, disabled and enabled ???

 

[Bugler101]

still don't see 8gb memory. I tyried playing with Surround View and got my self into a real mess. Had to remove bios batterys and reset bios to get the darn video working again. This is turning into a nightmare. I have done everything suggested with no success. Any suggestions of who I might contact to resolve this?

 

[johnbl]

force a kernel dump and put your dump on a cloud share, we can look at it with a debugger and see what the BIOS reports to the OS. here is how to force a memory dump:
http://msdn.microsoft.com/en-us/library/windows/hardware/ff545499(v=vs.85).aspx

- many motherboard makers will check to see if the memory is on the Qualified vendor list, if not they tend to give generic advice and punt.

-I suggest the memory dump because some BIOS settings might be ignored or incorrectly stored or read from the BIOS.