[SOLVED] 8GB (3.93Gb usable)

[Kenju]

So my friend built a PC a few months ago and he just noticed on Windows he gets only 3.93gb memory instead of 8gb.

In BIOS we see the 8gb of RAM just fine.

We tried almost everything, resetting BIOS, change RAM Slots, Format the drive and install new Windows but nothing seems to solve this issue.

CPU : AMD Ryzen 5 2600
Motherboard : ASRock B450M Pro4
RAM : G.Skill Aegis 8GB DDR4-2400MHz (F4-2400C15D-8GIS

 

[brispuss]

Under msconfig (Start > msconfig > Boot tab > Advanced options > "Maximum memory" box), this maximum memory box should be unchecked.

 

[Kenju]

Apparently it was already unchecked. I tried setting manually to Maximum memory aswell, but neither did the job

 

[brispuss]

Update BIOS to the latest version.

Remove the CPU and check it and it's socket for any sign of damage, dust, dirt, or debris. Check that all pins are OK (not bent nor damaged) and remount CPU carefully and evenly. Uneven CPU mounting can cause memory issues.

 

[Kenju]

Update BIOS to the latest version.

Remove the CPU and check it and it's socket for any sign of damage, dust, dirt, or debris. Check that all pins are OK (not bent nor damaged) and remount CPU carefully and evenly. Uneven CPU mounting can cause memory issues.

BIOS update didn't work. But it would be available all of it (8gb) in BIOS if it was uneven cpu mounting ?

 

[brispuss]

First, confirming that this system is running under Windows 64 bit, and not 32 bit?

A CPU that is mounted unevenly means that some contact between pins and pads are lost. So this loss of (some) electrical contact means the CPU can't function properly. One common side effect is "loss of memory", the system typically loses about half of the installed memory.

So it is important to mount the CPU evenly to ensure proper pin to pad contact and therefore have the CPU function normally.

Another thing is that the G.Skill memory part number F4-2400C15D-8GIS is not listed anywhere as being compatible with the ASRock B450M Pro4 motherboard with the Ryzen 5 2600 CPU installed. This suggests that this memory is incompatible, and could therefore be (one of) the reason(s) why not all physical memory is available to the system.

But, despite this memory being not listed in memory compatible lists, this does not necessarily mean the memory is incompatible. This is because not all possible combinations of memory/motherboards are tested due to large numbers of components involved and limited time for testing.

Please check the CPU and its socket for any sign of damage, bent pins, debris etc.

Please ensure the CPU is mounted evenly/level.

If the issue persists with only 3.93 GB usable, then we'll look at other options.