Mixing same spec RAM, but manufactured at different dates

[GFork]

Hi,

I built an i7 system 2 years ago with the following RAM:
Corsair DDR3-1600 CL8 3x1Gb (TR3X3G1600C8D)

Recently I wanted to upgrade the ram, and bought the following Corsair DDR3-1600 CL8 3x2GB (CMP6GX3M3A1600C8)

I ran the original set of ram using the XMP profile setting in the bios. I then added the new ram I bought, which booted fine. However when running benchmarks/games I get almost instant bluescreens. (left XMP profile setting enabled in bios)

I then removed the old ram, and placed only the new ram in the same slots. Booted, did benchmarks/stress tests with NO problem. (using XMP profile)

Finally, I inserted the old ram again so that both are present, but I disabled XMP - setting the speed manually to DDR3-1600.

Now all works fine.

1. Is there any particular reason for this?
2. Is there a way to enable the XMP profiles?
3. Will I have overclocking issues using these two sets of RAM combined?

Thanks!

 

[GFork]

Not exactly answering my post, but true...

I suppose the other question is, how much better is the speed on the ram running XMP settings, or just manual DDR3-1600?

 

[GFork]

Best answer selected by GFork.

 

[Maziar]

This topic has been closed by Maziar