8G Ram installed but 4G usable

[Dave noob]

I had the same problem two days ago when cleansing my computer. I pulled out everything from the board including batery (to clear CMOS), and when I installed everything back again and started the computer, bios shows that memory is 4 GB but just 2 GB enabled.

I got it fixed by pulling out memory and installing it back while shorting the "clear CMOS jumper". I have P55A-UD3P with F14 bios, so I guess it may help.
Don't forget to umplug the power cord before doing this.

[Dark Mantis]

If you want to clear the CMOS at least do it properly and leave it for a few hours to make sure that all charge has dissipated. Like this:

Remove the power cable from the mains supply and then press the power switch on the case for a few seconds just to drain any residual energy in the PSU capacitors.

Once done remove the motherboard battery for at least one hour before replacing it.
 
Next plug back into the mains supply and boot.
 
You will now need to enter the BIOS by pressing DEL and load Optimised BIOS Defaults.

Make any other changes to the BIOS settings to suit your self like disabling the floppy drive, disabling the full screen logo and making the HDD the primary boot device and then press F10 to save and exit.


Regarding the photos I am afraid they were of rather poor quality and the flash especially ruined them. Better to use "macro" setting and with good natural light or at least diffused lighting so there is no glare. Please post some more.

[JFC15]

hmmmm...   

Tell me about your memory modules...  make/model

All modules are the same make/model... correct?

What is your DRAM voltage setting in BIOS?  Since you are using all the slots, you might have to increase board default voltage.

Did you try testing memory with MemTest86?

[Dave noob]

Something strange happened when just 2 GB of 4 GB was usable. WEI scored my memory 5.5, down from 7.9 but my 3DMark vantage score goes up to 18576 from initial 18100. Resource meter reported that the 2 GB is reserved to be used by bios and hardware.

I just wonder, if I install 8 GB bust just 4 GB enabled, may I have even higher score in 3DMark?

[Dark Mantis]

I can only suppose that if the extra 4GB had been allocated to the graphics processing rather than the system it would have given you a higher graphics rating in WEI at the expense of the memory score. I just can't imagine why iot would happen like that.