Mixing old slow RAM and new fast RAM

[Fireman Dave]

I was given a PC that had 4GB of A-RAM DDR3 1333.
Not long after this, I purchased 8GB of G.Skill Ripjaws X DDR3 1600.
For the past couple of months I've been running the PC with both installed.
Is this a good idea? Could the cheap / nasty RAM be hampering the new RAM? Or is it better to have the 12GB?

 

[i7Baby]

It's better to have just one type of ram. You should just use the 2 x 4gb 1600. Quite often mixing ram causes BSoD's.

 

[Fireman Dave]

No BSoDs so far, but I have been wondering whether the slower RAM would be holding the faster RAM back?

 

[Tradesman1]

What the DRAM running at? Can check with CPU-Z in the memory tab - it will show true freq (800 for 1600, 667 for 1333 since this is Double data rate DRAM)

 

[Fireman Dave]

What the DRAM running at? Can check with CPU-Z in the memory tab - it will show true freq (800 for 1600, 667 for 1333 since this is Double data rate DRAM)

535...
https://dl.dropboxusercontent.com/u/83859030/Clipboard02.jpg

 

[Fireman Dave]

Pulled old RAM, new RAM now running at 602.

 

[4Ryan6]

Click on the SPD tab in CPU-Z and see what timings and voltage are spec'd to run 800 and manually set those in the BIOS.

Check your M/B manual and put the 8g 2 x 4g modules in the dual channel slots ASUS recommends them to be installed in.

 

[i7Baby]

Or just enable XMP in bios

 

[Fireman Dave]

RAM currently in recommended slots.
Turned off overclocking, and under AI Tweaker in the BIOS set tuning to DOCP, then selected 1600 profile. RAM now running at 800 ^_^

 

[Tradesman1]

Sounds good !