Thoughts on GPU thermal issues

I’ve been playing around with several devices in a context of running OpenCL code on them. They have one common thing which is excessive heat coming out of GPU and heatsink being unable to dissipate it. I start with MacBookPro3,1. It has NVIDIA 8600M GT, which is known to fail. I assume that it may be linked with overheating. Second example is design failure of Lenovo Thinkpad T420s which has built in NVIDIA NVS 4200M. This laptop has Optimus feature which in theory could detect if workload should be run on discrete or integrated GPU. Unfortunately enabling either Optimus or