CPU-Z always shows Asymmetric

[theoldtannery]

I have a system running well at 3.22GHz with a matched pair of Ballistic PC2-8500 at 920MHz. However, CPU-Z always shows the memeory as Dual Channel Asymmetric rather than symmetric. Timings are 5.0-5-5-16 at 2.2v. Everything is rock solid. Does anyone know why this might be and whether this is telling me that I am not yet optimising my memory setup? I am using the black sockets on a P5KC with BIOS 903 at the moment. I see many other screen dumps of people with Symmetric dual channel operation. My BIOS says Dual Channel Interleaved as it posts.

Thanks