The mosfet's will have a thermal pad on it, You could probably replace this with MX-2, but they are pretty uneven and you might not get proper contact on all of them without a thermal pad.

Not sure what the safe temps are for the mosfet's but they must be able to withstand a good amount of heat.

although im highly interested in people with experience in this mod chiming in something that i learned from a recent thread is that if your end up putting your mx'2 on there make sure that it doesnt touch any other components

im assuming mx-2 has some electrical conductivity like AS5 im not sure though.

the mosfets on my air cooled x58 e758 are in the 80's and are easily the hottest part in my case.

Yes, you can swap the thermal pad for thermal paste but as stated, the process can be tricky since the heatsink usually doesn't conform to the profile of the MOSFETs well.

You may get lucky and have the heatsink fit well against the MOSFETs or it may fit badly.  Kind of luck of the draw.

If you want to do it, be prepared to do it to the end or have a spare new thermal pad handy in case you ruin the original and see that the work necessary to make the heatsink fit well with TIM is too difficult.

The Process:

Remove the motherboard from the case.  Remove the Vreg (MOSFET) heatsink by unscrewing the two screws on the backside of the motherboard.  Make sure you use the right size screwdriver otherwise you can easily round off the screws.  Remove the thermal pad.  Apply a small amound of thermal paste to each MOSFET.  By small, I mean less than an 1/8" dot.  Press the heatsink up to the MOSFETs by hand and then remove the heatsink again.  See how much thermal paste transferred from the MOSFETs to the heatsink.  If thermal paste transfer was poor, it means that your heatsink is warped differently than the motherboard and TIM will not provide good heat transfer.  If the two MOSFETs -- one on either end -- have poor contact, file down the heatsink standoff so that the heatsink will sit further down on the MOSFETs.  If the two end MOSFETs have good contact but the middle has poor contact, bend the middle of the heatsink down so that better contact is in the middle.  Etc.  This is a long process to get correct.  If you damage the heatsink, you are in a pickle.

Good luck. 

The advice so far is good, and suffice to say that ty_ger07's was the most *sobering*! None the less, it is a good thing to fix one way or another, as VREG temps in the 80's are excessive, and need to be fixed.

I guess I'm a lucky guy! The reason I write that is because the procedure that I went through was pretty straight-forward. I didn't have a big gap in the sealing of the MOSFETs, I just had a couple thermal pads that needed to be taken OUTAATHERE! In my case, the pads were mis-applied, didn't fit or conform to the shape of the MOSFETs at all, and my fix turned out to be a better situation.

I used Artic Silver Alumina, which is also a lighter-textured TIM, pretty "creamy and nice" to work with for this application, and it sealed the MOSFETs pretty much spot on the $$$. The VREG temps on that board were in the high 70-'s to low 80-'s originally, and after the treatment/procedure they mellowed out to the low 50-'s at idle, to mid 50's/low 60-'s under load, a big, BIG difference!

I do *not* use fans on the VREG to this day, as after the treatment the temps have remained as above, 50-'s and 60-'s...on the E758 board. My Classified has been a good/great board all the way since I broke the box, for comparison, as the temps there have been low since Day No.1. I have never seen VREG temps higher than 59-degrees on the Classified, and that includes some rather extreme torture testing with 12GB RAM, 4438Mhz speed, and a warm evening to contend with.

I hope you have some good luck, and that your VREG MOSFET's are conforming and easy to work with...if there's anything to be said about doing this job, it's this: you probably will not make it worse no matter what you do, if the temps are in the 80-'s or higher, so be patient, be good, and most of all, be lucky!

rexrzer77