 Obviously over the next couple of years, we're gonna be building a ton of sick water-cooled gaming rigs using RTX 3000 series graphics cards like this one. But while in the past we were able to use the old rule of thumb, which is about one 120 millimeter worth of radiator per heat generating component in the system, I don't necessarily think that the rules of it should work necessarily apply to the RTX 3000s. Particularly the power-hungry and enormous RTX 3090. So today's video is gonna be us taking you along for the journey of some work that we would have had to do anyway. Figuring out exactly how much radiator we need for a water-cooled RTX 3090. We're gonna start with a slim single, which probably ain't gonna work, and work our way all the way up to, well, realistically whatever it takes. Just like I'll do whatever it takes to transition to our sponsor. Ridge Wallet wants to redefine the wallet with its compact frame and RFID blocking plates. Check out how they can keep your wallet bulged down and use offer code LINUS to save 10% and get free worldwide shipping at the link below. Before we can water cool it though, we need to figure out how well the system performs when it's just air-cooled. So for the testing, we're going to be using this Asus Strix RTX 3090. You might remember it from our, is SLI actually dead video? It basically is. So yeah, let's just chuck it in here and find out how well she goes. Our fan config in this case is a bit overkill, if I'm honest. We have three fans in the base that are just blowing straight up into it and three fans up here and three that are blowing up there, nine in total. It's a bit ridiculous, but at the same time, like, you know, you want best case scenario for your card. So we've got our test set up here. Just a very simple times by extreme. We're going to enable looping and let it go for 30 minutes. It's been 30 minutes, just 32 at this point. And what? Oh my God, you piece of crap. Why is there no monitoring data? Yeah, I have to do it again. Well, see you tomorrow. Okay, testing's done. It looks like we don't have any issues with thermal throttling whatsoever. So hovering rate around 1800 megahertz and let's see here. But come on. What a beautiful card. I haven't been this excited to take something apart for a really long time. This is my first look at the inside of an Ampere card. And what a beauty. We're going to be using the EK Quantum Vector today to water cool it. Here's the back plate. That's actually really nice. Damn. Look at that. It's just so nicely machined. The real star of the show here. Okay, this water block's $175. That's enough to buy yourself a pretty decent GPU. But you know, you've already got a 39. So who cares? Everything should be CNC machined. I was hoping that we'd get a see-through one. This is kind of a pre-production block. So we don't have, you know, the things you might expect it to include, like instructions. This is all that I've got. It's a little PDF that includes where the thermal pads go. And that's it. That's all we get. Probably going to be fine. All right. All the thermal pads are on. Finally get to just apply some thermal paste. Get it all over here. Oh, wow. Oh, wow. Huh. All of these mounting holes don't quite line up on the block because of these two capacitors right here. Yeah, this is bad. So should we? Yes. Oh. Oh. Oh. Garly. Okay. We should have the clearance now. But hopefully by the time, you know, actual real people get this, they don't have to do that. Even with a water block on it, the thing is still huge. Massive shout out to EK, by the way, for sending us over one of their first vector Strix blocks for the RTX 3090 from ASUS. It did come with some growing pains in terms of installation. They actually hadn't accounted for a couple of capacitors here. So we had to make our own clearance for them. But now that it's on, theoretically, I think we should be okay. So this is as simple as let's fire it up and get going. Yeah. Power this puppy up. We're going to need not one, not two, but three 8-pin PCI express connectors. And then I've gone ahead and installed the plugs down here and we're going to throw some fittings on here and build ourselves the dirtiest water cooling loop that you ever did see. I mean, not literally dirty. It's going to have clean water in it, but just kind of gut spilling all over the table style. Obviously, Nvidia's last few generations of graphics cards have thermal throttled at about 80 degrees so effectively that you can't really use temperatures to determine if a cooling solution is adequate. Nowadays, you have to just monitor the boost clocks that the card runs at to see if it's reaching its full potential. So this air-cooled RTX 3090 from ASUS represents the numbers that we actually already ran on this exact card because there are variances from one to the other. And that'll tell us how much radiator reaches the threshold of the air cooler and then how much radiator we need to, if there is any more headroom, exceed it. For convenience, we're using one of these pump reservoir combo units. These really are the fastest way to fill up a loop and get all the bubbles out of it because the water goes directly into the inlet of the pump. And you've got this little anti-vortex thing down here in the bottom that helps the bubbles make their way out of the liquid. One thing to watch out for is modern GPU blocks like CPU blocks can be directional. So this particular one has the inlet on the left here so the water flows down into the cold plate and then it actually splits and flows along two different paths to help with flow restriction. Boy, when we build an ugly loop, we build an ugly loop. It's not that bad Linus. This sag is something else. Yeah, that's pretty bad. Card looks curved. That's okay though because you know, you can make yourself feel better with a refreshing drink from LTTstore.com. Hey, there it is. All right, to keep our results consistent, the pump is going to be run at full speed all the time. And then our fan for the radiator or radiators is going to go to the system fan header and we're going to configure it in the BIOS so that they're all running at about, I don't know what's reasonable, like 1200 RPM, I think is a good balance between noise and cooling. So we'll go with that. I got all those bubbles in there. You got to get them out. See now it's grabbing that water. Oh, this is great. We were fighting with smart fan mode with all these different temperatures, which by the way is very cool and you know different fan RPMs, but you can just turn it off. That's not a drop down. It's a check mark. And you can just set it 50%, which gives us around 1100 RPM on this fan, which is pretty quiet. Like, but then the main reason that you go water cooling these days is of course A for looks and B for quieter operation. If you don't want it quiet, don't water cool. I mean, where is it? Look at the cooler on this thing. Like, so yeah, that's what we're going to settle on. It's pretty crazy to see an RTX 3090 even at idle running at 32 degrees Celsius. Damn. Dang. And that's even with room temperature water that we put in here because we didn't want to wait forever for it to heat up and reach equilibrium. Good luck little radiator. I'm rooting for you, buddy. I'm going to take lunch. We returned from lunch to find our system black screened and unresponsive. Thankfully, our data logging still worked and we discovered that our GPU shot up to 87 degrees immediately after the test started, which is obviously not right. Even with an inadequate radiator, the water would still need time to heat up. So upon further investigation, we discovered that in any case, mad rush presumably to get us one of these blocks ahead of retail availability, they the block is great, but they appear to have made a small boo boo and sent us two millimeter rather than one millimeter thermal pads. So here's the one they sent us against a one mil. What that did was actually prevented the GPU from making proper contact. You can see we've done a test fit now and everything's doing great with the one mil. So we just need to remount this and take another crack at it. Ow. It's really hot. That's not quite as bad, but the tanks on the sides of the radiator. I'm surprised we changed our test methodology. Long story, but we're using firm arc and letting it reach equilibrium, then logging for five minutes. And it's like turboing completely to two gigahertz and maxing out at sixty six degrees. In fact, what's weird is like the back of the GPU, we put some tape on it to deal with the reflectiveness of the of the backplate there. So the GPU itself is actually running it around the same temperature as the back of the backplate. That's crazy. That RAM on the back of the card must get freaking toasty. Maybe we shouldn't be that surprised, though. I mean, we've seen a 1080 Ti and what an 8600K on a single 8700K on a single 120 millimeter radiator. That's not to say that we think this is ideal. Let's see how much better we can do with a better rad. To say our results from the thick single were a disappointment would be an understatement. We've got basically the exact same temps, even though we amped up the thickness of our radiator. Although think about it, it does kind of make sense because we are adding some more surface area, but we're also adding more restriction to the airflow. So you tend to need higher RPM or higher static pressure fans to get the most out of thicker rads. Actually, here's another thing I didn't notice until I went to do that B-roll shot showing the relative thickness. The high performance thicker one actually has kind of like a built-in shroud. So you can see there's more space between where it screws in and where the fin stack is. So the difference in thickness of the actual cooling element is not as much. You can see it also has a much more dense fin arrangement. It's possible then that a more powerful fan could have improved our results with the thicker radiator, but not to the degree that we'd be getting temperatures that I'd be happy with on water cooling. So let's move on to a dual 120 millimeter radiator. This is also of the dense fin thicker variety. Come on, pump. You can do it. Half an hour into our dual rad, I got to say I am blown away. Like I knew it was going to perform better. Two fans is definitely better than one, but wow, we went from 66 degrees down to 48 degrees. That's almost a 20 degree drop just by adding a little bit more radiator surface area. So without testing the triple, I can already say that this is probably going to be the sweet spot for performance and noise. Just because I'm not expecting a big difference in performance this time around though, doesn't mean I can skip out on testing the triple. What you get with an overkill sized radiator in addition to potentially lower coolant temperatures is more headroom for optimizing your system. For example, if you've got restrictive grills on your case, a larger radiator can help compensate for less airflow. In the same way, you could just turn your fan speeds down if you wanted your system to operate more quietly. Finally, of course, there's the F word, future proofing. If you've got a larger radiator and you do decide to add another component to your loop down the road, it's more likely that you'll be able to do so without changing out your rad. As expected, we only dropped about four degrees this time telling us that our sweet spot really is a double radiator. But if we wanted some room to grow or we knew that we were going to be giving up a bunch of our airflow to something like a restrictive fan filter, then a triple would be a great bet for an RTX 3090. This is crazy because that means that doing small form factor machines with a high performance CPU and an RTX 3090 is basically going to require either a dual and a single or two triples. And remember too that the scenario we're testing here assumes that our radiators are going to have access to fresh air. Sometimes they're going to have a mixture of fresh air and case air. In fact, like you see in a case like this one, where there's kind of like a gap between the back panel and the fans where it can kind of mix what comes in through the grill and what's already present in the case. So now we know, just like we all knew that I was going to use this opportunity to tell you about our sponsor. Micro Center promises you the best prices and selection across any of their 25 locations across the United States. You can join the new Micro Center community to give and receive advice on PC part selection and hardware. And you can check out their custom PC builder configurator. Just check out the link in the video description for a free 32 gig flash drive and 32 gig micro SD card valid in store only. No purchase necessary. If you guys enjoyed this video, you might enjoy other water cooling experiments like, oh shoot, I don't know if this one's going to be up yet by the time you guys watch this, but what in the heck is this thing, ML360 Sub-Zero?