1. Could you please point me to that macworld article, or better, to benches, since I couldn't find any of them at macworld website.
2. I guess, my standpoint needs some more detailed explanation. GK104 (680/770/780m) and TahitiXT (7970/R9-280x/D700) initially pretty much tie in gaming. 680 had the TDP of 200w and performed similar (if not a bit better) to 7970 that had 250w TDP. 770 vs R9 280X is the same story. I see zero reason, why 780m vs D700 shouldn't fit that scenario, since their TDP difference is even smaller (100w vs 108w).
3. What is "base clock TDP"? What the hell is "boost clock TDP"?? The particular card has the only one TDP (108w in D700's case). If the card stays within its TDP while under load, it will boost its clocks. If it doesn't - it lowers them. No way it will magically become a 150w+ GPU under load. It's as simple as that.
1. Unigine Heaven and Valley 1280-by-720
Mac Pro 8-Core/3.0GHz (Late 2013) 103.70 80.30
27-inch iMac quad-core/3.5GHz CTO (Late 2013) 90.46 80.84
Unigine Heaven and Valley 1920-by-1080
Mac Pro 8-Core/3.0GHz (Late 2013) 31.50 31.70
27-inch iMac quad-core/3.5GHz CTO (Late 2013) 24.62 26.98
Unigine Heaven and Valley 2560-by-1600
Mac Pro 8-Core/3.0GHz (Late 2013) 14.40 18.20
27-inch iMac quad-core/3.5GHz CTO (Late 2013) 11.91 14.98
So in Heaven and Valley D700 is 14 to 20% faster than GT780M. Also GT 780M is not comparable to GTX 680. That card is 20%ish faster than GT 780M both on Windows and OS X.
About TDP, the GPU's in Mac Pro seem to go well above the 108W since they measured 435W during the Luxmark Open CL test which pushes both GPU's to the extreme. The question is for how long can they keep that up.