Repasting Laptop CPU

Dracil

Hope this is the right forum (instead of Help/Advice), but because Borderlands 2 is causing my laptop CPU to hit the 90s, I've decided to repaste it even though it supposedly came with MX-2 applied. Bought a tube of MX-4 and Arctic Clean plan on doing this tonight. However, I'm still fairly new to this so I had some questions.

1. Normally I've heard you were supposed to do the middle dot method and then press it down with a heatsink to prevent bubbles, but I've read this isn't actually true anymore. i.e. it's only true for single-core CPUs and you want a line instead of a dot with multi-core CPUs since the cores aren't in the center. And with mobile CPUs, because there's no Integrated Heat Spreader, you're actually supposed to spread the past over the entire thing with a razor blade/credit card to make sure no part is left uncovered. True/False? Arctic Silver's site says to use the spread method so I'm assuming that's what I should do.

2. Assuming true, the spreading part raises some questions. Reading Arctic silver's manual, they keep warning about contamination with your finger, but wouldn't an old credit card be contaminated with all that same finger oil and other stuff? Can you just clean it with the same alcohol/cleaner fluid you use to clean the old paste? If I use the razor blade, should I be worried about scratching the CPU while trying to spread the paste or are they generally durable enough to not be a problem?

3. Regarding breaking in the paste, I have a habit of keeping my computers running all the time. Do I need to actually turn them off for proper break-in? Or will temperatures that vary from about 40-90 degrees from idle to game playing be enough for break-in?

Thanks in advance!

Alecthar

I don't see why a break-in would require a shutdown of the PC, but most pastes don't need on these days, and I've never used one that has, so I haven't paid attention.

I'd wash the card, or if you have clean plastic bags or powder-less examination gloves, you can just use your finger. Razors are fine for a chip with a heat spreader, but I'd be worried about accidentally gouging the chip itself with a corner or edge. Spreading the paste sounds like a reasonable method.

When cleaning the paste off, make sure to use a lint-free cloth, I like disposable coffee filters.

Donovan Puppyfucker

Regarding paste application techniques:
There seems to be a lot of over-thinking this going on in this inter-connected series of tubes.
From a commonsense point of view, it doesn't matter how many or where the cores are under the heatspreader, as the heatspreader itself is the only component we can actually draw heat from. Too much paste will inhibit the heat transfer process, so go with the credit card or razorblade to spread it extra thin over the whole heatspreader. Conundrum solved?

As for laptop chips with no heatspreader, you still want to cover the whole top of the chip obviously, so the same process logically applies. If you've got wobbly fingers, leave the razor blade in your razor, and chillax.

Stormwatcher

I just spread it with a folded paper (to make a stiffer edge). Seems to have worked fine for the last 15 years.

Dracil

Welp, I repasted. Probably used a little too much. But I also noticed the heatsinks were gunked up when I removed the fans, and I think cleaning that helped a lot more than the repasting. Max temps went from about 95 to 75. I also noticed one of my cores was around 3 degrees higher during idling, but ended up being less than the others under load. Weird.