 So the conventional wisdom, at least used to be, that when you were shopping for a power supply, you could basically judge the quality by the weight. The heavier the power supply, the better it probably was. That is until some cheapo manufacturers started literally putting hunks of metal in them to make them seem better. That got us thinking, what about hunks of metal? Could you literally walk down the cooling aisle with a luggage scale and buy the heatsink with the best price to weight ratio to cool your CPU? Maybe. G.SKILL's KM780R mechanical keyboard features a brushed aluminum top plate on the fly macro recording and various Cherry MX keyswitch configurations. Learn more at the link below. We know more weight, or mass if you want to be pedantic about it, does not mean better cooling. A two kilogram block of aluminum on top of a CPU would weigh a lot, but wouldn't do a good job of cooling it down. For long. So, what you're actually after when it comes to dissipating heat is surface area. The more surface area that you have, the more cooling will be available. So then, if we assume that most commercial CPU coolers are designed by mechanical engineers and not by chimpanzees, and that most companies are interested in saving cost while optimizing performance, then it would make sense that most heatsinks out there represent the manufacturer's best efforts to strike a balance between material cost and heat dissipation. So assuming that everyone has done their homework equally, the heavier the cooler, the higher the performance should be. But, as we know so very well around here, not all engineering is equal. So, we grabbed a bunch of coolers off the shelf and devised a test. The weight of each cooler was recorded with the fan, but without mounting hardware. We kept the room at a consistent 24 degrees Celsius, and set the fan curve to full speed on our system for all of our tests. The CPU we used was a Core i7-7700K, with the AIDA64 FPU test running for 30 minutes before the average package temp was taken for the next five. And looking at the results, there are actually some very interesting takeaways here. First of all, the NH-D15's outperformance of every AIO liquid cooler is a great testament to how well engineered it is. And, while we're praising strong products for their efficiency, Corsair's dual 140mm AIO outperforms the Thermaltake Triple 120 AIO, which has worse case compatibility. If I had to hazard a guess here though, I'd say that this is down to the similar surface area of these two layouts, and the design of the fans. The most striking thing about these results though, is that after a weight of about 400 grams, the heat transfer to weight ratio absolutely plummets, with the coolers that remove the most heat per gram being the lightest ones. Why is this? Well, getting finally into the purpose of making this video, to let Alex nerd out for a bit, it's actually because of a design concept called the infinite fin approximation. Basically, for a fin of similar thickness, material, and airflow, it can only get so long, that is to say the distance from the heat source before adding more material is basically a waste. This concept is illustrated using this graph, where the Y axis represents heat flow. One would be all of it, and zero would be none. So for an infinitely small fin, you would dissipate zero heat, if that makes sense. And for a mile long fin, I mean by the tip of it, practically all of the heat from the source would have been dissipated to the air, before it could possibly be conducted there. That is why in the early 2000s, CPU coolers transitioned from fin or flower based designs, to the heat pipe ones of the late 2000s, and the liquid cooling designs that are common today. So newer CPUs generated more heat, but they didn't get any bigger. So there was no point in making the fins longer, which means that these new high conductivity fluid based mediums, heat pipes, and water helped solve the challenge of moving the heat away, to length optimized fins elsewhere. Is this something that we can show happening in real life? Actually, yes! The easiest way is by using this FLIR1 thermal camera. Looking at the Noctua NH-U12S, the ends of the fins come in at about 38 degrees Celsius, 14 degrees above the temperature of the room. Whereas on the massive NH-D15, the fins are only about 31 degrees Celsius. And remember, the lower the difference in temperature, the slower the heat transfer. So, with a given heat load, these longer fins are cooler, and therefore are dissipating less heat per amount of material. Bringing us then finally back to our original question. Can you judge a cooler's performance by its weight? Well, actually, it turns out you kind of can. Surely there are some exceptions out there, and some did better than others, but everything we tested seems to have had some engineering thought put into it. So that's good to know. We are working with Rosewill to give away nine, that's right, nine of their... Nebula series gaming headphones. They've got the GX10, GX30, and GX50 models. The GX10 features leatherette ear cup cushions, bright blue LED backlighting around the ear cups, and compatibility with most devices, not to mention a $25 price tag. While the GX30 and 50 both have detachable microphones as well as RGB lighting, but the GX50 has 7.1 virtual surround. So the GX30 is 35 and the GX50 is 45 to purchase at the links below. Oh, and also linked below is the link for the giveaway. Nine chances to win. Go check it out. Thanks for watching, guys. If this video sucked, you know what to do. But if it was awesome, get subscribed, hit that like button, or check out the link to where to buy a cooler in the video description. 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