DELL has done the same thing, in fact the very problem i was talking about was due (in part) to defective design where both the CPU and GPU were on the same heatsink and one would throttle the other.
From what I've read, the XPS 15 has a similar issue. It's a 45w CPU and a 60w GPU (960m) in a chasis that can really deliver about 90w to both continuously. Something has to get throttled under full load. The Precision 5510 (same chasis as XPS) uses a more balanced 45w CPU with a Quadro M1000M (also 45w) for 90w draw between the two.