Not being an extreme enthusiast I have not been able to find a definitive answer to this.
I'm asking because I own a Lenovo T520 thinkpad an i7-2720QM and NVS4200M with optimus (partnered with the HD 3000)
I have to disable optimus and force the laptop permanently into discrete graphics mode in order to obtain a WQXGA resolution (this has its own set of problems, but ones which I don't think are relevant here).
I can see from http://scr3.golem.de/?d=1101/Sandy-Bridge-Test&a=80409&s=19 it suggests that it is possible, and indeed it seems beyond belief that it would not be. However when my laptop is in in optimus mode or in integrated graphics mode, I have not been able to successfully drive a WQXGA resolution. The maximum that is offered is 2048x1536 (4:3) QXGA.
I'm just wondering if someone can point me to some documentation that clarifies this and/or someone else on the net who has actually been able to successfully do this?