All ram not usable unless in single channel

[Dimos187]

Hey everyone,

Just finished building a Ryzen 7 1700 system using an MSI B350M Arctic Mortar motherboard.

I am using 2x4GB of Corsair Vengeance LPX 2800 MHz RAM, but if I install them in the 2nd and 4th dimms as per manual, Windows only shows 4gb usable and 4gb reserved.

If I use the first two slots Windows shows all 8gb as usable, but then it is only running in single channel.

I have confirmed all 4 dimms detect the ram, by using a single stick in each slot one slot at a time.

Also I can only get the 2800 mhz XMP profile to work when only one stick is installed in the second slot.

Any help would really be appreciated!

Thanks.

[Princess Luna]

Being a brand new build there's 2 likely issues that could be the fault.

 

1st is an outdated BIOS, the first gen chipset for Ryzen specially MSi boards had a huge amount of issues and updating your BIOS to the latest version could solve compatibility issues.

 

2nd a bit more unlikely but possible no less, excessive pressure on the CPU by the cooler (if aftermarket more specifically) if you put far too much pressure the first thing that's likely to fail is the memory controller making only one channel function.

[Dimos187]

Thanks for your response. I have already installed the latest bios and am using the stock AMD cooler.

[Dimos187]

I decided to pull the cpu out and inspect it very closely as I purchased it used. I discovered a few pins were slightly bent. I managed to straighten them and now all the ram slots are working and my ram is running at 2800MHz. It has crashed a couple of times though, so might have to play around with the CPU more.

[thedangerine]

13 hours ago, Dimos187 said:

I decided to pull the cpu out and inspect it very closely as I purchased it used. I discovered a few pins were slightly bent. I managed to straighten them and now all the ram slots are working and my ram is running at 2800MHz. It has crashed a couple of times though, so might have to play around with the CPU more.

Yeah bent pins are typically the culprit when it comes to ram issues, especially when certain slots or dual channel acts up