780m is 100-122w tdp, its the same gpu on the imac 27, the 680mx a full gk104 core.No. That GPU's TDP is more than the the rMBP's all together (I believe).I am expecting no more than the750/60M with 1 GB GDDR5.
I disagree on processor nodes, maxwell is a new arch and where we are predicting big jump in performance, off course since they have started this 2 year schedule, a node bump doesnt kill anyone does it?Don't expect any big jump in rMBP GPU performance until there's a new process node for Nvidia which won't be until 2014. As an above poster posted, 750M is most likely chip which is basically a higher clocked 650M that's found in the current rMBP.
which in turn needs a 150w psu to provide power, there is magic and there is unicorn power, and in other news there is a 85w adapter that apple still usesrMBP 15" might have something like the 765M which is found in the new Razer Blades. The 14" version of that has a similar overall size to a 15" rMBP so might be.
The rMBP does have the retina screen though, so depending how much power that draws (vs the 1600x900 Razer (I think)) it may have one of the lower cards.