Long story short i`ve had a g551jm since december last year and wan't quite please with it regarding the cooling or the throttling. I am also upset because ASUS does not provide all windows 10 drivers for it(but it's not annoying).
The worst part about this laptop is the crappy way to be cooled(i am looking at you g551JW too). Those freaking tiny holes under the keyboard can't do s**t.
So, to cut the chase. I drilled about 15-20 4mm holes under the cooler(voiding my warranty which i will not need because the temps do not reach over 80 degrees celsius now) to actually help the vent get much needed air into it(also helped by a coolerpad which shaves of another 2 or 3 degrees).
CPU FPU TESTING and over burning at stock frequencies at 75 degrees or 80 max after some time ? gaming hard at 60-65degrees gpu for hours ? DOUBLE CHECK !!!
Asus seriously needs to revise it's designs. I also do not approve of a product that needs undervolting/clocking to be used within safe temperatures.
Paradox: I am happy with my laptop and with the rest of it(asus does make good stuff) AFTER i drilled the holes. And no, i still do not care about warranty because it will not be needed since cooling is done 300% better.
Small update. I have replaced the mx4 with Coollaboratory Liquid Ultra. Temps have been consistent during the last month so i will report that this is a much a needed paste for laptops. As a side note i currently have ~23C in my room. Laptop sits in idle at 31-32C and fpu stress testing has reached a maximum of 72-73C with this paste after a month of heavy usage(12H+/day).
2nd and 3rd update: After 3 months of using the Liquid Ultra paste, the temps are the same in full/high load. Cooling pad maybe shaves off 1-2 C but not more, so it is kinda useless now(except i need it to hold my laptop higher).
The better part is that i finally found a mesh to finish my cooling idea from an old coolerpad i had put somewhere. I have included a short fpu stress test. Temperature goes from 32 C idle to 60C > 65> 68 C and then slowly rises to 74 without cooling or 73 with external cooling.
Pics are below, the shape is non-conformist because the initial holes were a tad larger and the corner of the battery did not let me drill a large round hole as i'd wished.