All ram not usable unless in single channel

[mdimos187]

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 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.

Thanks.

 

[alexoiu]

Hi, I'd try updating the board's BIOS, if newer version available. Take though into account that a failed process might render the board unusable.

 

[mdimos187]

I have already installed the latest BIOS, but thanks.

 

[alexoiu]

Then try returning the RAMs and testing different kit.

 

[aquielisunari]

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 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.

Thanks.

Can you post a pic of your Resource monitor(Memory tab) with 8GB installed correctly?

 

[mdimos187]

I have tried another set of ram and still having the same issue. I have also used both sets in my personal PC and they work fine.

 

[aquielisunari]

I have tried another set of ram and still having the same issue. I have also used both sets in my personal PC and they work fine.

Are you a gamer? Can you post a Pic of your most RAM hungry game with as much eye candly and resolution as possible? Use MSI AB's OSD

and monitor your RAM usage. Some games are exceeding 16GB usage so increasing the RAM usage beyond 4GB should be easy.

We can wait for the game to install.

 

[mdimos187]

 

[mdimos187]

This isn't my personal PC, I haven't gamed on it. Built it to sell, but can't sell it until I sort out this issue.

 

[aquielisunari]

This isn't my personal PC, I haven't gamed on it. Built it to sell, but can't sell it until I sort out this issue.

I am not seeing the 2800MHz over at the QVL nor over at newegg BUT it should still work with the default speed which I think is 2133MHz. Did you perform a CMOS reset prior to each RAM test?

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

You possibly have a bad board.

 

[mdimos187]

So before the bios was saying 8gb, now it saying 4gb, but still shows both sticks on the board explorer.

 

[mdimos187]

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.