Gadgetory

hey everyone i'm steve from gamers nexus thought net and i'm joined by a patrick stone hey guys we're gonna talk about thermal interface today or a thermal compound mmm thermal paste so i guess the main purpose of this content is to explore why thermal paste is used to the different types of thermal paste or thermal interfaces and sort of dive into what it actually does we all know that it's siphons heat away from whatever it's in contact with but to what extent and why not just use copper I'll be good right because then you could just have metal on metal and it would make sense like if you're cooking on a stove you have the the burner and you put the piece of metal on top and it heats up right that's how it's supposed to work excite this kind of heat transfer works a little different different yeah yeah so with what CPUs will take as the standard example you have the CPU die the actual silicon on top of a substrate which is like green wait for chip singing yeah yeah maybe not really the best word right and then on top of the die is the IHS did a great heat spreader and that has sort of a convex bowing to it very slight but it's there and that has imperfections in the surface mm-hmm so why don't you walk us through the rest of the yeah so what's happening the way that I often explain it whenever someone is asking about it is if you got like a sandwich here you'd think that the IHS on the cpu would be a nice perfectly flat contact with the heat sink on top the bottom of the heat saying the cold play yeah the cold play exactly right and then so if you got those two things on top of each other stacked like that you'd think it'd be perfect heat transfer but if we get to it on the micro level like on the microscopic level you can see in there it doesn't look anything like a flat surface on a flat surface so what we've got to do is we've got to fix that because we definitely do not want air right as our medium for heat transfer you were telling me it has some kind of very low thermal conductivity so the the way that thermal conductivity is measured is in a unit called watts per meter Kelvin mmm yep and with copper you have about 400 watts per meter Kelvin of thermal conductivity believed at 25 Celsius with aluminum it's half that it's about 200 watts per meter Kelvin yep it's so pretty good right and that's why in our copper versus aluminum cold blade test you see copper outperforming but just barely it's actually very it's a very small difference right unless you move to like the x99 big CPUs right so with with aluminum and copper you have 200 to 400 watts per meter Kelvin thermal conductivity and then with thermal paste like any of this stuff this is probably four to seven mm-hmm watts per meter Kelvin very small compared to metal yeah but air is haribol haribol so yeah so we're gonna try and do then is we want to get rid of the possibility of having air in between our heat sink and our integrated heat spreader we want that to be a perfectly conductive mechanism and so in order to fill that gap we're just gonna squeeze some throw phase in there we're just gonna just ooze it on and just like jam it in but like a tube of toothpaste well no not exactly so what we're gonna do that well I guess there's different ways to apply it there all right I don't think that they are all correct I've seen you know the put it on and use a credit card to smooth it method I don't like doing it so different ways to do it the way I normally do it is sort of a grain of rice sighs mm-hmm blob of thermal paste right in the center and then when you tighten the actual CPU cooler onto the bracket you want to do opposing corners yeah so that it applies the the pressure to the surface equally yup and distributes the thermal compound on it I like that I like that thought that's good train of thought I actually usually go with one of two things if I'm lazy and I just want to get it on quick I'll go with very similar to the grain of rice thing the size of like a dinner pea like you know like a green pea right and I'll drop that right in the middle and again when when you put that heatsink right on top of the integrator each spreader it's gonna it's gonna force that stuff outward there's some really cool videos on YouTube about that and this actually shows like with a glass plate on top of the grid looks better right the other method that I like a lot because it gets really good coverage on the integrated heat spreader is if you like kind of draw like an X on to the integrated heat spreader and you don't want to draw the X from corner to corner you want that extra bit sort of in the center because again when you press down with the heatsink it's going to spread that out as you make the surfaces meet another thing that you were telling me that that was really really good to remember is that we don't want a huge amount of thermal kind and why was that well too much is worse than none at all hmm with this stuff and that's because with with not at all what's happening is you have tiny imperfections in the surface of the IHS and of the copper cold plate or aluminum cold plate those imperfections are just a byproduct of the machining process it's not something that can really be avoided unless you're doing you know space engineering level of validation so that's unavoidable and those imperfections are what introduces the air pockets the air pockets get really hot but it's worse to have an entire surface covered with compound mmm where you have zero copper to IHS content yeah yeah so in that case if you had to choose none or way too much you're better off with none yeah yeah and to go back to like having copper on copper I remember back in shoot I guess five or ten years ago now there was a it was really popular to do what was called laughing where you actually take them and sand them down to get more of that smooth to smooth but again the concepts are all still the same you want as much copper on copper as you can get and you don't want air so you gotta have some thermal compound so on this thermal compound stuff what what would you say is probably some of the best mixtures out of the silicone is it's kind of like the most basic it's kind of stuff you're gonna see the liquid yeah and you're gonna see it on like an expensive electronics like in a router you might have silicone in between the routers central processor and it's heatsink but those are meant to produce tons of heat transfer what's what's a better compound there's there's like the nano diamond compound so there's different types of compounds some of it this this coolermaster stuff is actually really bad this comes with I think it came with an AMD CLC or something like that right this stuff will stick the cold plates of a cpu and you all break pins getting at all no G's which I've done so it does impact it the we have some other stuff here there's there's diamond compound which is some of it is harder to spread mm-hmm yeah that's true that's a good point and so that that can be an issue you can heat it up in like a cup of water if you really have to I've seen that done before you just get a hot cup of water put the tube in there yeah they can't dry it off right fine it so if you can't get it out of the tubes and that's that's a way to do that but that's the really hardcore stuff it's gonna have the highest thermal conductivity mm-hmm it's not necessarily worth spending 20 or 30 dollars on a tube of thermal paste unless you're an extreme over the other you can buy stuff like this stuff is all six bucks yeah maybe as much as like 12 or 15 to 12 yeah right but not ridiculously expensive yeah so there's what else is there other than diamonds there's a silicon compound yeah silver base stuff silver based yeah I remember there was stuff called mx2 back on the market several years ago and basically it's got metal in it and the amounts of metal are gonna help to conduct electricity electricity excuse me heat better so that's certainly something there the other thing I was thinking about is do do we need to be worried about it breaking down over time oh right yeah so thermal compound can sort of crack as it dries and moves right and there's also a curing process some of the thermal paste good point will perform much better as it ages you know there's there's a tipping point where that's no longer true but you know if the Machine returns and all that but eventually when you start with the thermal compound you should actually see worse performance earlier in the testing then maybe a couple days down the line yeah normally and then as it ages has it heats up it'll crack so then you have issues of like with laptops where you're replacing the thermal compound for GPUs and laptops yeah that's because it just it just incinerates an easy useless too hot too often yeah and then I guess the final topic is different types of thermal interfaces yeah so there's pastes well so like just today we were looking at a motherboard and we're looking at the VRM and around the vrm instead of thermal paste making contact with the transistors in the VRM it was actually this sort of like a pad material yeah and it's the same stuff that I'd seen do in repairs on like a PlayStation 3 or an Xbox 360 you there give me pink they can be you know grey they can be white but it's just a it's almost a rubbery feeling foamy feeling material and it does the same sort of thing it's there for that that conductive heat transfer it's just not on the same level I say the this more expensive thermal compound right and it also one know where the item is that it will conform to the surface better yeah that's a really good point so if you have like a choke that's more of a square and you want to get some coverage over the sides of it and you'll get that from the pads and GPUs do the same thing if you pull apart a GPU you'll find that the heatsink the aluminum heatsink is often applied somewhere near or on the vrm and the vram module yeah to using some sort of pad or film or adhesive that isn't a paste basically yeah so I think that about covers the thermal interface stuff I mean there are probably several other smaller topics but those are the kind of things that we wanted to talk about for sure yeah so if you like this kind of content as always check the patreon link in the post roll video help us out I think we're up to 26 or something backers now which is video awesome much appreciated on that and I check the next video we're gonna film some more stuff so I'll see you all next time