Unmatched pairs (2x4GB and 2x8GB) on a P67 Sabertooth

[Kelvarr]

Is there any issues running the following configuration together?

Asus P67 Sabertooth B3
Intel i7 2600k

G.Skill Sniper F3-14900CL9D-8GBSR
G.Skill Sniper F3-1866C10D-16GSR




Would I run into any theoretical problems? I am currently running two pairs of the G.Skill Sniper F3-14900CL9D-8GBSR, but am looking at trading one pair for the 16GB pair.

Thanks!

[Tradesman]

It may or may not work,different density, different CL....I don't think I'd buy to try, but if I had them available I'd try the 8GB sticks in 1-3 and the 4GB sticks in slots 2-4, with initial timings of 10-11-10-30, 2T, DRAM voltage at 1.56, VTT at 1.17, CPU at about 4 GHz, and VCCSA at 1.12 (I had an opprotunity to play with a very similar setup) and then if all well could try tightening the timings