Cooling mod for insanely low CPU and GPU temps! (bottom cover + U3 fan mod)

*credits go to deadsmiley for discovering the original mod over at TechInferno, and Gerik from OCN for the awesome Notepal U3 fan mod*

*may as well give a shout out to sl44n3sh at TechInferno as well for the various mods*

Yours truly is running a P370SM with 4900MQ and 780M SLI. The 4900MQ has been pasted with Liquid Ultra and running a -80mV undervolt. The master 780M is using an 880M heatsink, but otherwise everything is stock, including vBIOS and clockspeed. The 780Ms are on a month-old MX-4 paste job.

In my quest to run my laptop as cool as feasible, I came across two enormously helpful mods: deadsmiley's GPU cooling mod, and Gerik's Notepal U3 fan mod

I want to say I was the brain behind this mod, but sadly I was just following instructions this time. Since deadsmiley already has a very detailed guide on how to perform this mod, I'll just cut to the chase and show you the end product and results:

The first order of business was to enlarge the air intake vents of the fans, which of course meant taking a Dremel to the plastic cover, then covering the holes with some metal screen:

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Master GPU


CPU


Slave GPU

I opted for the "easy and lazy" method of using foil tape to attach the metal screen to the holes instead of deadsmiley's more permanent adhesive method:

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Master GPU


CPU


You may have noticed the CPU opening is slightly smaller and does not encumber the entire circumference of the fan. That's because there are some support structures (the black "fins" at each of the four corners) that get in the way, and I did not feel like cutting those out.

Slave GPU

Old and new side by side:

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And this is what it looks like on the laptop:

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For the U3 fan mod, once again Gerik has an excellent guide up, so I won't repeat myself. I will just say that the fan controller has some QC issues, and mine had a dead DC jack on arrival, which made me think the whole thing was DOA for a while. However I was able to get it to work using an AC to Molex adapter that was meant for HDDs, and plugging into the Molex end of the fan controller. It looks a bit cumbersome as a result (as you'll see shortly), but on the plus side I gain the ability to switch the fans on and off at will.

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You see what I mean by cumbersome? Granted it doesn't look too bad in this picture because I hid all the fan wires LOL, but believe me when I say it's a handful (literally). The green light is the on/off switch from the AC adapter, which I really appreciate, as I would otherwise have no means of manually controlling the fans aside from unplugging the controller.



The wires for the 3 120mm fans can be neatly routed through the back of the U3, and don't get in the way at all.

So now the million dollar question: but will it <del>run Crysis</del> actually do anything? Short answer: YES! Long answer see below:

Since I did not feel like needlessly torturing my 780Ms with Kombustor or Furmark, I decided to play Watch Dogs for 30 minutes and record the max and average temperatures for the CPU and each GPU. All temperatures were logged with HWInfo64, and in each run the ambient temp was 24C.



The CPU benefited the most from having more access to air, as just by enlarging the fan opening the temperature dropped by 6C. Having the 120mm fans on did not seem to make a difference, and indeed peak temperature was actually 1C higher. This may have something to do with the CPU fan being smaller and more susceptible to turbulence.

Likewise, simply by giving the fans more access to air both 780Ms saw a 2-4C drop in average or peak temperature. However in the case of the GPUs, the 120mm fans had a positive effect on temperature, as they further dropped the temperatures by 5C for the master 780M, and 2C for the slave 780M. The reason why the master benefits more is because the GPU heatsink opening in the bottom cover is directly in the line of TWO 120mm fans, and so the GPU die receives additional cooling on top of its own fan. The slave 780M doesn't benefit from this as the heatsink opening is too low for the 120mm fans to be of any effect. Still, we can see that forced induction is beneficial in this case. I'm rather amazed how good the results are, and one can only imagine what sorts of temps would be possible if one used Liquid Ultra on the 780Ms.

However, as great as the temps are, there is one (potentially major) downside -- noise. The fan noise is noticeably more audible with the holes in the bottom cover, and the 120mm fans just add to it when run full blast. Although I did not find it overbearing, I did have to turn up the game volume a notch. So there is some sacrifice to be made if you're after the lowest temps possible, and if you're very noise sensitive you may want to think twice before modding.

As an alternative for the noise sensitive, you may want to open up just the inlets for the GPU heatsinks (the part that has still has holes right above the GPU heatsink), so you can at least get better airflow onto the die without the side effects of increased noise. One of these days I may get around to cutting those out as well, and I'm confident I'll see another 2C drop in temps.

Final thoughts:
If you don't mind sacrificing fan control for max speed all the time, a 12V/2A AC to Molex adapter, followed by a 4-way Molex to 3-pin fan connector would also work.

And I'm still amazed that the Rosewill RFX 120 fans fit the U3 perfectly without the need for any modding. Seriously the screws are just the right diameter, so the fit is neither too tight nor too loose, and the screw holes on the 120mm fans are just in the right position, not a single mm off. It's almost as if the Notepal U3 was designed with the Rosewell 120mm fans in mind[/url]. Very intriguing indeed.

 

Nice work! I think I like the square holes better. The aluminum tape idea is a good one too. I wish I had thought of that. The tape I have is super skicky and stays where I put it.

And for the record... This isn't really my mod, its just my version of one that I stole from Tech Inferno, credited in an update to my original post.

 

I would spray the fan shield (cover) from silver to black to match the black back panel. Very nice work n=1. I'm impressed.

 

Ah cool, found another mod along the same lines at TechInferno so added that as well.

Thanks! Yeah I may get around to that eventually, but I'll leave it for now and see how fast dust and other stuff accumulates to see if this is even a viable long term solution. Worse comes to worst I could always just go back to the stock cover and use the Rosewill 120mm fans. But the modded cover will be perfect for summer gaming sessions in a relatively hot room (up to 28C/82F at times).

 

Yes! I read that thread before and couldn't find it again. Bookmarked it now.

 

Interesting, I might have to try something like that. Right now, I just run it without the cover and with spaces on the sides... probably not the best idea.

 

I like the course screen better than my door screen. I will keep my eyes peeled for something like that when I am out at the hardware store.

 

If you sand your heatsinks you will drop another 5c I would guess. Maybe more.

 

hey, a link to U3 fan mod pls

 

dude the link's literally in the 5th line of the first post

 

dope now i just have to find some parts

 

I have problem understanding this.... Am I correct that you basically cut off the parts behind fans and replace them with holes that are exactly as large as fans above them, to improve airflow? Is it necessary for the hole to fit the size of the fan (not larger either)?

 

As long as you cut a hole (square/round/rectangular, doesn't matter) that completely encompasses the fan, that is enough to do the job.

 

Thanks! Does this mean I can just remove the cover??

 

If you mean remove the bottom cover entirely sure it's possible, but I definitely wouldn't recommend using your laptop in such a condition unless you're doing extreme benching.