Overview This thread is essentially a compilation of the various mods I performed on my P370SM to improve its cooling capabilities over the period of several months. Most of these mods have been documented in detail, but the actual posts/threads are scattered all over the forums, with some even in the Alienware section. I am now piecing everything together into one central thread, both for my own benefit, as well as other P370SM owners. Most of these mods should work equally well for the P370EM, P375SM, and P37xSM-A. However, I am confident that a few of these mods will be universally applicable to other laptops (Clevo or otherwise) that suffer from the same issues. The initial impetus behind all this modding was the increased temperatures due to the summer heat. As there is no AC in my room, the ambient temperature is typically at least 24°C (75°F), and on hot days it rises to an uncomfortable 29°C (84°F). My initial goal was rather unambitious, as I simply wanted my P370SM to never exceed 80°C on any of the components during summer gaming. But as I kept modding and temperatures kept dropping, eventually it became an obsession to see just how low I could push the temperatures. I am still not quite finished with modding at this point, so this post may be updated from time to time as I complete and validate any new mods. Before I begin, I must acknowledge a few key people that motivated or helped me along the way to keep all this modding going. They were the brains behind a lot of these mods, and I was simply the technician. -deadsmiley for discovering the TechInferno mod, as well as his own mod that helped me get the ball rolling, and for providing very helpful tips and pictures when it came to lapping the heatsink -sl44n3sh at TechInferno for various mods - Gerik at a certain overclocking site for the awesome Notepal U3 fan mod The P370SM: A Brief Introduction The P370SM is the second iteration of Clevo's mobile SLI laptops (the first being P370EM). Compared to the P370EM, the P370SM made several major changes to the cooling system, among them the omission of the third heatpipe from the CPU heatsink that shared the slave GPU fan, beefier 6mm heatpipes for the master GPU (instead of 4mm in the P370EM), and a one-piece construction for the slave GPU heatsink that now sat flush with the fan and had no issues with air leakage due to unnecessary voids. While these improvements are welcomed, I feel that Clevo made a number of questionable design decisions, and the end result is that the cooling is still not as good as what it should be. Thus the task is placed upon the end user to rectify some of these issues and unleash the full potential of the P370SM. For reference these are the main specs of my P370SM: -4900MQ -780M SLI -2x8GB 2133MHz ram -1TB 840 Evo boot + 500GB 840 Evo data -Running Prema's BIOS mod v2 for the P370SM Everything was run bone stock (clockspeed, vBIOS) for all testing. Liquid Ultra was used on the CPU, while MX-4 was used on both GPUs. With that out of the way, let the modding begin... The Mods: Part I External Cooler Mod For some reason TechInferno doesn't allow me to state where the original mod came from, but if you google "Gerik U3 mod" the second result takes you to the source thread. Basically, he combines 3x 120mm Rosewell RFX-120 case fans with a Notepal U3 cooler. Since Gerik has an excellent guide up, I won't repeat myself here. 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. 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. This is probably the easiest mod of them all, and for such a small amount of effort, I recorded a 5°C drop on the master GPU and 2°C drop on the slave GPU. Not bad at all. GPU Cooling Mods Exhibit 1: Sealing unnecessary voids I'm really not sure what it is with Clevo and voids, but here you go. The fix is to simply tape off the offending area of the fan with some foil tape. It takes literally less than 1 minute, and the result is a 1-2°C drop in temps when gaming. Exhibit 2: An improved heatsink When I was going through HTWingNut's review of the P377SM-A, I noticed that the 880M heatsink for the master GPU in the P377SM-A seems to have slightly improved compared to the 780M heatsink: it is now a one-piece construction instead of separate core+vRAM heatsinks, so one doesn't have to worry about misalignment between the two parts obstructing airflow and, perhaps more importantly, fin area seems to have increased (thanks Meaker!). As a bonus, the 880M heatsink includes a bit more foam padding on the fins to block off the atrocious void I mentioned in exhibit 1. So does the 880M heatsink actually offer any improvement over the 780M heatsink? Yep it sure does. The following records the temperature taken at 1 minute intervals while running MSI Kombustor 3.0: I was very happy to find that the 880M heatsink did indeed perform better than the 780M heatsink; not only was peak temperature reduced by 2°C, it also took longer to reach the peak temperature. Exhibit 3: Opening up restrictive vents Have you ever taken a moment to stare at the fan grilles on the bottom cover? I certainly have, and I've always wondered just how much the fans are being starved of air by these tiny vents. This is what the vents on the P370SM look like; for comparison this is what the bottom of the Alienware 18 looks like. See the difference? The baffling part is that Clevo clearly realizes the importance of non-restrictive vents, because the P570WM has some pretty awesome vents. So why the vents on the P370SM are the way they are I don't know. The fix is easy enough if you know what you're doing: take a Dremel to the bottom cover and cut some holes. And here's a bunch of close up shots: Master GPU CPU Slave GPU 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 By simply allowing the fans more air, I saw a 3-4°C drop in temps on both the master and slave GPU. Exhibit 4: De-warping aka lapping the heatsink I will admit to being completely ignorant to this issue until Khenglish at TechInferno pointed this out: Now you know why the temps suck despite the strong fans. But as you will see towards the end of this long post, when all (or most) of the issues are rectified, the cooling system finally starts to tap into its full potential. The fix for warped heatsink is both easy and hard: it involves lapping the heatsinks, or sanding down the uneven parts until you achieve an almost perfectly flat surface that has a mirror-like finish. The fix is very simple conceptually, but the execution can be rather difficult on a laptop heatsink. I started with the slave GPU heatsink as the contact plate had no "tabs" on 2 corners unlike the master GPU heatsink (see exhibit 2 for pictures), so the contact plate was completely flat, and easier to work on. The materials I used: I skipped both the 400 and 600 grit as I didn't want to take too much material off. The metal block to the far right is a 1-2-3 machinist block, which provided the flat surface I needed to sand down the heatsink. So what I did was use the 3" side of the 1-2-3 block and cut a piece of sandpaper that was just slightly larger than the area of the contact plate on the heatsink. For the actual lapping I pretty much just followed the guide from OverclockersClub that I linked to above. Every 3 complete rotations I washed off the copper shavings on the sandpaper, and reapplied dish soap to the heatsink. I went 800, 1000, 1500, and finally 2000 grit. I had 2500 grit sandpaper but quite frankly I was just too tired at the end and decided to call it a day. The entire lapping process took about 2 hours, and both my hands and wrists started giving out towards the end. You will need a lot of patience if you want to do it right, so make sure you're in the right frame of mind when doing this. This is NOT something you want to rush, as I can tell you from personal experience that I almost trashed my heatsink because I was rushing the first time through. Also, the actual process is very messy as copper containing water/foam will get everywhere, so either do this outside or near a sink, and make sure you wear nitrile gloves. The end result does look quite stunning though: (note that this is actually a second lap; the first one was botched because I rushed so again DO NOT RUSH THE PROCESS) From left to right: before lapping, 800 grit, 1000 grit, 1500 grit, 2000 grit For 2 hours of my trouble, I shaved 3°C off the slave GPU while gaming. The rather modest drop is because my plate wasn't all that warped to begin with, as I know deadsmiley who had a rather warped plate experienced a drop of over 10°C. For the vast majority of you this may not be worth your trouble, but to a temperature obsessed enthusiast like me every °C counts, so I'm happy with the result. Summary of Results for Part I They say a picture is worth a thousand words. If you don't feel like reading this gigantic wall of text (which I totally understand), then hopefully this single image will be enough to convince you that these mods really do work. Below I have recorded the temperatures, both the absolute peak as well as the average after 30 minutes of playing Watch Dogs on Ultra with 2x SMAA. ***I should emphasize that the 880M heatsink was used for all these tests, so "no mod" should really be "880M heatsink only*** With all mods incorporated, both the master and slave 780M experienced a 7-8°C drop in both the peak and average temperature. This may not sound very impressive given all the mods, but check out the actual values. You're not reading them wrong, even a demanding game like Watch Dogs barely pushes my 780Ms past 70°C, with the average temperature just around the 66°C mark for both. This is absolutely remarkable, and just goes to show how much power the cooling system can deliver when the design flaws are rectified by the end user. - - - Updated - - - The Mods: Part II PCH Cooling Mod In case you didn't know, the PCH chip is located under the keyboard in the P37xSM models. (see pics below) As you can see, the PCH just quietly hides under the keyboard, with no access to air or ventilation of any sort. Because of this and the high summer heat, my PCH would idle at 62°C, and could go up to 83°C when gaming. Since the keyboard backplate is one big piece of aluminum, I figured why not bridge the gap between the PCH and the keyboard and use the keyboard as one gigantic heatsink. So I used my caliper to measure the gap between the PCH die and the keyboard backplate, and it came in around 4.2mm. I figured 2x2.5mm thermal pads would do the job nicely: (here I actually just used the stock square 2.5mm pads that go on the inductors from a spare 780M heatsink, they fit very nicely and the size was perfect) Look at the nice impression the die makes in the stacked pads: I didn't expect too much from this mod, since I'm stacking 2 thick, stock Clevo thermal pads, and the pressure isn't that high. But even with this rudimentary mod, the idle temp dropped by 7-8°C, and the temp maxed out at 73°C after an hour of playing Watch Dogs, representing a 10°C drop in load temps. The keyboard did not feel any noticeably warmer, probably because the heat is concentrated between the "\" and "enter" keys. However I will say I don't know what the long term consequences for the keyboard would be, so do this at your own risk. CPU Cooling Mod Remember the triple pipe CPU heatsink of the P370EM I mentioned earlier? Well turns out this fits in the P370SM just fine, and gives the CPU healthy temperature drop because of the extra cooling from the slave GPU fan. The problem is that all the extra heat from the CPU is 100% off-loaded to the slave GPU, which is completely unacceptable in gaming situations. I'm not going into any details here because this isn't really a worthwhile mod unless you're into hardcore CPU benching. In any case I wrote about my findings here, so all the details are there for you to see.