Mixing RAM 8GB+4GB+4GB?

[Skull_Pirate]

Is it OK to mix RAM of same speed, but different size and manufacturers? Will it degrade my overall RAM performance? My current 8GB stick is in slot #2.

[Khenglish]

You have 4 slots? 8GB in one channel, with 4GB + 4GB in the other will perform just like a single 8GB stick in both channels.

[Skull_Pirate]

But my 2 4GB sticks are 1.5V and my 8GB stick is 1.35V, will that cause a problem?

[1pinkpanda1]

I'm not sure about the voltage, but I think it should be fine, although it might mean the 1.35V stick will run at 1.5V and waste a little bit of power.

I know for sure that using different sizes will work fine, but you might want to check the CAS latency on the different sticks since they're different manufacturers. I have two 8GB sticks, a 4GB stick, and a 2GB stick in my machine, all 1.5V (DDR3 instead of DDR3L, which is 1.35V) but the latencies don't match so the machine is stuck using the latencies from the slower two sticks. I think the performance difference is very minor though.

Also in my experience my BIOS reacted strangely to the latencies that didn't match; all of my four sticks are 1600 MHz but instead of taking the lower latency and running all four at 1600 MHz the machine defaulted to taking the faster CAS latency but dropping the clock speed to 1333 MHz. Once I manually set my clocks and latencies it worked fine but the machine wouldn't resume from sleep properly. So tl;dr, in my experience mixing RAM worked fine and there was a minimal performance loss that I could counteract with a lot of headache.