ASRock is well known among PC enthusiasts for its graphics cards, motherboards, power supplies, and gaming monitors. Now, it has entered the market for liquid cooling solutions. We’re looking at two of the company’s first AIOs here, the Phantom Gaming 360 LCD and Steel Legend 360 LCD. Both of these liquid coolers feature 3.4-inch 480 x 480 displays for showing off animations and monitoring performance metrics. Aside from aesthetics, the main differences between the two are the included fans and radiator size. The Steel Legend 360 incorporates a standard 27 mm thick radiator, whereas the Phantom Gaming 360 uses a thicker-than-normal 32 mm radiator.(Image credit: Tom's Hardware)Let's take a look at the specifications and features of the coolers, then we’ll go over thermal and noise benchmarks and decide whether ASRock’s Phantom Gaming and Steel Legend AIOs deserve to make our list of the best CPU coolers.Cooler specificationsCoolerASRock Phantom Gaming 360LCD/Steel Legend 360 LCDColorsBlackWhiteMSRP$189.99$159.99LightingCPU block, radiator, and fansCPU blockWarranty6 years2 yearsSocket CompatibilityAMD AM5/AM4Intel 1700/1851Radiator dimensions397mm (L) x 120mm (W) x 32mm (H)397mm (L) x 120mm (W) x 27mm (H)Maximum TDP (Our Testing)>260W with AMD’s Ryzen 9 9950X3D>260W with AMD’s Ryzen 9 9950X3DFeatures of ASRock Phantom Gaming & Steel Legend 360 LCD▶️ 60hz 3.4-inch LCD display(Image credit: Tom's Hardware)Both the Phantom Gaming 360 LCD and the Steel Legend 360 LCD include a 3.4-inch square IPS screen with a 480 x 480 resolution and 60 Hz refresh rate, with brightness rated at 250 nits. (Image credit: Tom's Hardware)To control and customize the screen, you’ll need to download ASRock’s Polychrome Display software. You have the option of selecting six preset themes, or you can build your own theme, and/or customize the individual elements shown on the display. (Image credit: Tom's Hardware)While I certainly wish there were more presets available, my biggest complaint using this software is the extreme file compatibility limits. If you’d like to upload a custom background, the image or video file needs to be less than 20 megabytes and 1080p or lower in resolution.(Image credit: Tom's Hardware)▶️ RAM ClearanceAs with most liquid coolers, the design of both the Steel Legend and Phantom Gaming 360 has the CPU block set so it doesn’t overhang or interfere with the DIMM slots – ensuring that all sizes of RAM, no matter how tall, are compatible.(Image credit: Tom's Hardware)▶️ VRM fanIncluded on top of the CPU block is a 70 mm, 3,000 RPM fan designed to help keep your RAM and motherboard’s VRM modules cool. As you’ll see in our Karhu benchmarks, it does an excellent job of cooling these parts of your computer. (Image credit: Tom's Hardware)▶️ Thick CPU cold plateThe copper contact plate is unusually thick, like you’d more typically see in an AIO supporting AMD Threadripper or Intel Xeon server CPUs.(Image credit: Tom's Hardware)Differences between the ASRock Phantom Gaming 360 LCD and Steel Legend 360 LCD▶️ Color schemes and aestheticWhile they are similar in many ways, each of these AIOs has a different aesthetic, similar to what you’d see in the company’s motherboard lines. The Steel Legend might appeal to those who prefer simpler designs, with a white body and gray fan blades. (Image credit: Tom's Hardware)If you want flashy lighting, the Phantom Gaming 360 might be your thing. In addition to ARGB lighting on the fan blades, it also includes a lighting strip across the side of the radiator. (Image credit: Tom's Hardware)▶️ Radiator sizes: 32 mm and 27 mmThere are two primary technical differences between the Phantom Gaming 360 LCD and the Steel Legend 360 LCD; one of those is the radiator size. The Steel Legend 360 LCD has a standard 27 mm radiator, whereas the Phantom Gaming 360 features a thicker 32 mm radiator.(Image credit: Tom's Hardware)▶️ 120 mm fansThere’s more to a liquid cooler than just the radiator and liquid pump. The included fans directly impact noise levels and cooling performance. This constitutes the second primary technical difference between the AIOs we’re reviewing today.Both units include fans that are 28 mm thick and pre-installed for user convenience. The Steel Legend 360 features three individual 120 mm fans, with a white shell and gray blades. (Image credit: Tom's Hardware)The Phantom Gaming includes a fancier fan block instead of individual fans, and features ARGB lighting on the fan blades and a strip across the radiator. These fans aren’t as powerful – or as noisy – as the fans included with the Steel Legend, but this is balanced by the thicker 32 mm radiator included on the Phantom Gaming 360 LCD. (Image credit: Tom's Hardware)Steel LegendPhantom GamingFan Speed0 - 2500 ± 10% RPM0 - 2400 ± 10% RPMAirflow76.7 CFM61.28 CFMAir Pressure4.16 mmH203.11mmH20PackagingThe outer packaging is a bit flashy – at least, in comparison to your normal AIO box. It features a rendering of the cooler against a black background with streaks of purple hues. (Image credit: Tom's Hardware)The inner packaging is just as fresh as the outside, with each component of the cooling system well protected from the chaos that shipping can bring by using a combination of soft covers and individual cardboard walls for each component.Tom's HardwareTom's HardwareIncluded with the package are:Mounting hardware for AMD and Intel platformsTubing clipsA small tube of thermal paste360 mm radiator and 120 mm fans3.4-inch LCD display(Image credit: Tom's Hardware)AM5 InstallationThis section assumes you’ve already mounted the 360 mm radiator. Installation of AIOs is typically much easier when you have already secured the radiator to your computer case. To begin putting things together, you’ll first need to remove the default AM4/5 retention from the motherboard.(Image credit: Tom's Hardware)The next step is to place the mounting bars on top of the studs, securing them with the included screws. The middle of the mounting bars includes a helpful image indicating the direction the bars should be installed, with an arrow pointing towards where the CPU should be.(Image credit: Tom's Hardware)Now you’ll want to apply the included thermal paste. If you’re not sure how to do that, we have a handy thermal paste application guide that covers the different methods you can use. Afterwards, place the pump block against the CPU and mounting bars, and use a screwdriver to secure it. You should have the liquid tubing in the south position for best thermal performance. (Image credit: Tom's Hardware)The next step is to slide the LCD display on top of the VRM fan. To complete the AIO’s installation, you’ll want to connect the USB, PWM, and ARGB headers as appropriate – then you can power on your system.(Image credit: Tom's Hardware)Real-world testing configuration – AMD AM5 platformWe’ve tested coolers with both the Ryzen 9950X3D and its non-V-Cache sibling, the 9950X. There are some differences in how the 9950X and 9950X3D CPUs are impacted by thermal events. While the heat output of the CCDs of AMD’s 9950X3D is relatively balanced, the 9950X I used has one CCD that runs much hotter than the other, with a difference of over 10 degrees Celsius in some scenarios, shown below.(Image credit: Tom's Hardware)We’ve since returned to using a 9950X3D for cooler testing, as it has a more balanced heat profile, and is almost certainly a more widely adopted CPU. The benchmark results shared in these reviews may differ from others because I emphasize results that are comparable to real-world use. This means I generally test CPU coolers inside of a closed desktop case, which increases cooling difficulty compared to other testing methods. Many reviewers test coolers on open test benches, which have a combination of lesser airflow needs and lowered ambient temperatures. This results in making weak coolers appear stronger than they really are. Some also use generic thermal plates to test cooling solutions. I reject both of these methods because they don’t accurately reflect real-world cooler conditions.CPUAMD Ryzen 9 9950X3DGPUMSI Ventus 3X RTX 4070 Ti SuperRAMTeamGroup Diamond Rose T-Force Xtreem DDR5-7200MotherboardMSI X870E Carbon WifiCaseTryx Flova F50Our latest testing setup uses the Flova F50 computer case from Tryx. (Image credit: Tom's Hardware)This case features a unique “crossflow” fan that pulls air from the side, which the company claims is more effective than traditional intake fans. For air cooling tests, we’ve added a single Noctua NF-A12 G2 intake fan. We’re going to start this review’s benchmark section by focusing on a traditional maximum performance test, with the CPU cooler’s fans allowed to reach their fastest speeds for the best cooling possible.Turning on PBO allows AMD’s Ryzen 9 9950X3D to stretch its legs to an extent, and all air coolers I have tested with PBO enabled using MSI’s X870E Carbon Wifi motherboard reach the maximum CPU temperature of 95 degrees C (203 F) and thermally throttle to some extent.(Image credit: Tom's Hardware)The thermals of both ASRock AIOs are excellent, able to keep AMD’s Ryzen 9 9950X3D under its peak temperature (TJ Max) in Cinebench R23 with PBO enabled – allowing for the best possible benchmark performance. Of particular note is the performance of ASRock’s Steel Legend 360; it maintained an average of 61.5C over ambient (83.5C), the best result we’ve seen on this test bench.Some coolers perform well in maximum strength tests, but require running loudly to maintain said performance. The ASRock AIOs we tested reach 46.9 and 47.8 dBA, which is about average for most liquid coolers on the market. (Image credit: Tom's Hardware)200W thermal benchmarksFor the next thermal test, I leave the motherboard settings at their defaults, which results in a power limit of 200W when running Cinebench R23. (Image credit: Tom's Hardware)When a standard power limit is imposed, the thermal differences between the two ASRock coolers close, with both coolers performing about the same. I measured 47.3 and 47.9 degrees over ambient, giving them the third- and fourth-best performing results from this test bench. 150W + GPU thermal results, noise levelsOur next test runs Cinebench on the CPU with a 150W power limit, while also running Furmark on MSI’s RTX 4070 Ti Super Ventus 3x OC. This causes the GPU to consume ~295W of power. This test is designed to emulate the thermals of games, which primarily stress the CPU and GPU.(Image credit: Tom's Hardware)ASRock’s Steel Legend stood out in this test, outperforming all other competitors, with an average temperature of 57.4 C (35.4 C above ambient). The Phantom Gaming AIO also performed well, taking the fourth-place spot. But thermals are only part of the story. Noise levels, especially when you’re gaming, are far more important here. When tied to my motherboard’s default fan curve, ASRock’s Steel Legend 360 had a noise level measured at 39.2 dBA. The Phantom Gaming 360 LCD was just a hair louder, measuring 39.6 dBA. (Image credit: Tom's Hardware)Noise-normalized testingMost testing is performed with the cooler tied to the default fan curve of our MSI X870E Carbon motherboard, but some prefer to see tests when the noise levels of coolers are equalized. This is especially important to those of you who prefer silent computers. This next test has the CPU cooler noise-normalized to 38.9 dBA, with PBO enabled for the Ryzen 9 9950X3D CPU. (Image credit: Tom's Hardware)With recordings of 258.8 and 258.2W average CPU power consumption, ASRock’s AIOs perform essentially on par with each other while noise-normalized.Karhu DDR5 RAM thermals testingYour CPU cooler does not operate in isolation. It has an impact on not just your CPU’s temperatures, but also the other components in your build, like your RAM and GPU. To that end, I’ve run the Karhu RAM stress test. This places a load of ~153W on the CPU and ensures system RAM (DDR5 in my case) is fully stable. In this type of scenario, most AIOs tend to produce worse results than air coolers. (Image credit: Tom's Hardware)DDR5 temperatures were excellent in this test, with averages of 20.9 C (Steel Legend) and 21.5 C (Phantom Gaming) recorded. Of the AIOs I’ve tested on this configuration, only Silverstone’s IceMyst Pro with its unique stackable fans performs better.We’ve also included a chart showing the CPU temperatures in this test, and thermal performance was strong – outperforming air coolers by ~5 degrees C. But I haven’t recorded this data for other AIOs yet. (Image credit: Tom's Hardware)Conclusion(Image credit: Tom's Hardware)ASRock’s Steel Legend 360 LCD and Phantom Gaming 360 LCD are both strong coolers, well suited to heat-intensive CPUs like AMD’s Ryzen 9950X3D or Intel’s Core i9-14900K. Of the two ASRock AIOs, I would recommend the Steel Legend 360 LCD for users who want the best thermal performance possible (and a lower price tag). It might lack the thicker 32 mm radiator included with the Phantom Gaming 360 LCD, but its included fans are stronger, and as a result provide lower CPU temperatures and quieter noise levels in common scenarios. Still, at around $160, the Steel Legend is far from the most affordable AIO with a display, and it’s only available in white.