[SOLVED] CPU changed and RAM cut in half

[oliverkelly]

I have an ASUS Z170 Pro gaming motherboard, which has 4x8Gb DIMMS (Corsair CMK16GX4M2A2666C16R) giving 32GB RAM.
The processor was a an intel i5 - 6600 3.50 GHz

I upgraded the processor to an i7 - 7700 3.60GHz

The 32GB ram then reduces to 16Gb.

In the BIOS all 4 DIMMS can be seen each showing 8Gb in the DRAM status section. But the total memory changes to 16Gb in the information section, and that is all that is available to windows.

I have checked each DIMM separately, and in pairs. Swapped the pairs around.

If I put the original CPU back it jumps back up to 32Gb.

Still boots ok and runs windows, but I cant see why the ram reduces. thought it may be seating issue but have tried swapping the cpus back and forth

Am I missing something, or any ideas what the issue is?

 

[rgd1101]

turn on the xmp profile in bios?

 

[oliverkelly]

turn on the xmp profile in bios?

I tried that, and it doesn't boot at all.

 

[geofelt]

Your ram is not matched.
You have two 2 x 8gb kits.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.
I have no clue as to why a stronger processor should make any difference.
My suggestion is to go into the bios and increase the ram voltage from the default 1.2v in small increments.
Sometimes that will fix things.

If no joy, contact corsair ram guy, they may be able to help.