I have a similar problem. But with a Alienware 15 R3 which is still under warranty with Onsite Service After Remote Diagnosis (Consumer Customer)/ Next Business Day Onsite After Remote Diagnosis (Commercial Customer). Specs are: I7 6700HQ, GTX 1070, 16 GB DDR4 RAM running at 2667MHZ, Samsung 960 Evo M.2 SSD 512GB, Seagate Firecude 1TB HD, Samsung MZVLV128 128GB M.2 SSD NVME (OS). After 30 min of Prime 95, the result from Realtemp is disturbing with a different temperature between core 3 and 4 of 19 Degree Celcius, core 1 and 3 temperature are above 90. I believe this is a serious heat sink problem because I can't feel any hot air coming out of the vent. I've been trying to contact Dell through their phone number and so far I've received no support, they keep transferring me from departments to departments and wasn't being very supportive, it almost feel like they don't want to help or have no idea how to help. This is very disappointing because I pay a premium for this laptop and expect to receive good customer service, it feels like Dell warranty is nothing but a scam or Dell employees are not paid enough to do their job.