Having taken a look at asdad123's post on overclocking the rMBP, I downloaded Inspector and tried my hand at OCing my own unit. However, I've run into an issue that I can't seem to work around: there's no P2 mode available when setting clock speeds in Inspector. I've tried using -forcepstate for values of 0,1;0,2; and 0,5, but I can't force P2 mode, nor can I find it in the P-state drop-down menu. Without P2, I can't make use of the undervolting trick described here, and my GPU's running at a minimum of 1.037V when overclocked above 1035MHz. I'm worried that, without the thermal headroom afforded by P2's 0.95-volt limit, the lifespan of my laptop will be reduced due to high GPU temperatures. If anyone's figured out a way to enable P2 mode in the rMBP, I'd appreciate some advice greatly. I'm running Nvidia Inspector 220.127.116.11, with 306.23 drivers.