Mixing Old and New RAM?

[sparda1]

I have just upgraded my RAM from 2x4GB to 2x8GB and was wondering if I am able to add the old RAM to it.
I have read that some RAM should not be mixed and some can, but will run at the lower speeds of the old kit. If I can mix these two kits and it runs at the lower speeds, how noticeable would it be as opposed to just running with the 16GB?


Thanks.

Old RAM: G.Skill Ripjaws 2x4GB

• 
  DDR3 1600 (PC3 12800)
  Timing 9-9-9-24-2N
  Cas Latency 9
  Voltage 1.5V

New RAM: G.Skill Ripjaws X 2x8GB

• 
  DDR3 1866 (PC3 14900)
  Timing 9-10-9-28
  Cas Latency 9
  Voltage 1.5V

 

[elbert]

Sure you can add it but needs set to the lowest of the 2. IE 1600 may be the best speed. Not that the small differance will mean much.

 

[sparda1]

Sure you can add it but needs set to the lowest of the 2. IE 1600 may be the best speed. Not that the small differance will mean much.

Will I need to manually change it to the lower speed, or will it automatically do it?

 

[elbert]

Depends on the motherboard but there is a good chance your only running your RAM at 1333 then. Use CPU-z to see your RAM speed.
http://www.cpuid.com/softwares/cpu-z.html

 

[sizzling]

FYI it may not run at all, its not guaranteed it will boot and if it does boot you still might get stability problems, all you can do is try it.

However the fact you upgraded from 8gb to 16gb suggest you don't actually need more than 16gb for what you are using the pc for otherwise you would have upgraded from 8gb before now. Therefore I'd just stick with 16gb at the faster speed and sell your old RAM.

 

[sparda1]

FYI it may not run at all, its not guaranteed it will boot and if it does boot you still might get stability problems, all you can do is try it.

However the fact you upgraded from 8gb to 16gb suggest you don't actually need more than 16gb for what you are using the pc for otherwise you would have upgraded from 8gb before now. Therefore I'd just stick with 16gb at the faster speed and sell your old RAM.

I may just do that then. I have already had my PC randomly freeze a few times with the new RAM, requiring me to hard reset. Still trying to work that one out. I'll make a new thread for that, though.

Thanks.