Lapped heatsink == warmer?

[arsenius]

I lapped my heatsink (Vantec 6something something, really big, 6800RPM fan,etc...) expecting to make thigns a bit cooler, but instead they got warmer, and now my computer runs prime95 @ about 114*F

did I just not do a good job lapping it, or is the finish typically so good on the Vantec that it shouldn't have been lapped? It seemed to be pretty not smooth to me and very smooth now...

has this ever happened to anyone else?

[Colin]

Something’s not right here. Thermal grease application or the way the HS is seated on the chip. You did use a piece of glass or other flat surface when you lapped your HS, correct?

[J.S.]

What grit did you use? I used 1500,It should have a mirror effect when your done. Make sure its seated right on the cpu.I'm sure your using thermal paste ,so i wont ask.I lapped a Gorb i was using on a C2 i oc'ed because the Gorb suked and it did help a little,i would say check everything over and make sure everything is right,it should have brought the temp down some.Use Wet/Dry emory.use some water with it so you will get a smooth even surface and do it on glass.

[kat]

a good lapp job will result in the finish being like a mirror and very flat (piece of glass for suport) 1500 should be the last paper, finish up with rubbing compound on a dish towel

if you temps went up then i suspect that the hsf instalation was not corect

[Da Whip]

Try reading this attachment and see if you did it correctly.

[surlyjoe]

OK heres the deal ,if your reading the temp of the mobo and not the on die thermistor ,then the better contact you have ,the more heat transfers to the sink ,the hotter the sink gets, the higher the on board sensor reads, SO if you look at your manal ,youll prolly be able to tell if this is the case or not

[AKDUDE]

If you did a good job of lapping, its probably just the way the sensor reads the temp.
I was wondering myself about lapping, I lapped a no name "upgraded" heatsink I got with my bare bones system. It looked like a mirror when I was done. Lapping it and using Artic Silver over the TIM that was provided with it, dropped the full load temp to 37 from 46!
However, looking at my newly lapped heatsink, and seeing my face in its reflection, I wonder it it reflects heat back into the cpu chip (not the actual core)
Im thinking that infared heat would reflect back down towards the motherboard, but I guess since the sink is touching the core the major part of it is transfered out of the chip.
Now that I think back, I wish I would have taken just a tiny dab of artic silver, and rubbed over the bottom of the sink, so it would loose its reflectibility.
Right now, im just using the smallest portion I could spread out over the core.
AKDUDE

[wild_andy_c]

I got a FOP 38 as rough as concrete. Not very good at all. Lapped it using wet 600 grit, then polish and 600grit and got a mirror like surface.

Applied dow corning 340, and then acheived 4°C temperature decrease.

......but I would read some thought into surlyjoes response

[diehrd]

I doubt Heat is reflected from a mirror finish,Your heat source is not light,The cpu radiates heat,Kinda like heating a pipe at 1 end, and the heat travles up the length of pipe,to put a mirror above it ,would not reflect any heat back but woud slow down the disapation as a mere fact of obstructing it,Thats were fans come in, to push this heat away from its source.So covering the heat sink or messing up the finish would provide no cooling affect.I like you may be wrong so try it out But my money is on no cooling gain from a dull finish.A MIRROR FINISH WOULD REFLECT HEAT BACK IF THAT PROCESSOR GLOWED RED,bUT IF YOU GLOW RED YOU WOULD NOT BE POSTING HERE LOL.

[arsenius]

actually, they always say when cooking with tin foil to put the shiny side towards the food so that it reflects the heat into the food. I don't know if it really works though.

[AKDUDE]

since the heatsink touches the core, I would see no problems with reflected heat there. ALso there is thermal compound to transfer it.
But what about the rest of the heat sink? The parts that do not touch the core? If you lapped it to a fine mirror finish, yes, it would reflect heat.

Heat can be conducted through metal, and it can also be reflected.
AKDUDE