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CPU-only thermal results without power limits
Without power limits enforced on Intel’s Core Ultra 9 285K and i7-14700K CPUs, the CPU will hit its peak temperature (TJ Max) and thermally throttle with with almost all air coolers and even most liquid coolers on the market. For the best liquid coolers on the market, the results of this test will be shown using the CPU’s temperature. However, when the CPU reaches its peak temperature, I’ve measured the CPU package power to determine the maximum wattage cooled to best compare their performance. It’s important to note that thermal performance can scale differently depending on the CPU it’s being tested with.
We’ll start by looking at the performance of this cooler with Intel’s Arrow Lake Core Ultra 9 285K, as these are rather interesting!
Normally, when I’ve tested air coolers with Intel’s Core Ultra 9 285k, they run with the CPU operating at peak temperature and experience small amounts of thermal throttling as a result. Every air cooler I’ve tested thus far has demonstrated this behavior – until now! When I tested Jiushark’s JF800 did momentarily peak at maximum temperature, but operated without throttling – the first air cooler I’ve tested to accomplish this.
That said, Arrow Lake’s thermal characteristics have changed a bit since the launch due to both Windows and BIOS updates, which have altered its behavior. I’m going to need to retest coolers like Thermalright’s Peerless Assassin 140 as a result. It’s quite possible that other coolers can also manage this feat with Arrow Lake now.
Again, CPU coolers can scale (and perform) differently depending on the CPU they are paired with due to differences in manufacturing processes and the location of hotspots on the CPU. We’ve also tested Jiushark’s JF800 Diamond with the harder-to-cool Raptor Lake Core i7-14700K to see if its amazing performance would hold up with other CPUs.
With 254W cooled during the course of testing, Jiushark’s JF800 Diamond is again impressive! This is better cooling performance than I’ve seen from any other air cooler and competitive with many AIOs!
To achieve these levels of thermal performance, the fans of this cooler reach up to 48.9 dBA. This is much louder than it needs to be. I don’t understand why Jiushark allowed these fans to run so loudly, especially since – as the next section will show – they perform well even when limited to low noise levels.
CPU-only thermal results with noise normalized to 38.9 dBA
Finding the right balance between fan noise levels and cooling performance is important. While running fans at full speed can improve cooling capacity to some extent, the benefits are limited and many users prefer a quieter system.
With this noise-normalized test, I’ve set noise levels to 38.9 dBA using the i7-14700K system. This level of noise is low, but slightly audible to most people. Jiushark’s JF800 continued to offer the best performance we’ve seen from any air cooler here, with 236W cooled during this test.
253W results
My recent reviews have focused more on tests with both the CPU and GPU being stressed, but many of y’all have indicated that you would like to see more CPU-only tests. In response, I’ve started testing Intel’s “Arrow Lake” Core Ultra 9 285K with a 253W limit.
Testing with the default power limits of 253W shows very good performance, on par with Thermalright’s Peerless Assassin 140!
135W CPU + 290W GPU results
Testing a CPU Cooler in isolation is great for synthetic benchmarks, but doesn’t tell the whole story of how it will perform. I’ve incorporated two tests with a power limit imposed on the CPU, while also running a full load on MSI’s GeForce RTX 4070 Ti Super 16G VENTUS 3X.
The CPU power limit of 135W was chosen based on the worst CPU power consumption I observed in gaming with Intel’s Core Ultra 9 285K, which was in Rise of the Tomb Raider.
In this test, the JF800 Diamond continues to impress. With a temperature recorded of 66 degrees Celsius, it again takes the spot for the best air cooler, outperforming rival options from ID-Cooling, Thermalright, and Ocypus! Noise levels weren’t bad, but they were near the loudest of the results we’ve recorded thus far.
85W CPU + 290W GPU results
Our second round of CPU + GPU testing is also performed with Arrow Lake. The power limit of 85W was chosen based on typical power consumption in gaming scenarios using the Core Ultra 9 285K CPU. This should be fairly easy for most coolers. The main point of this test is to see how quietly (or loudly!) a cooler runs in low-intensity scenarios.
With a CPU temperature of 54 degrees C, Jiushark retains its lead over other air coolers. Its noise level was also relatively low in this test, averaging 38.2 dBA.
Conclusion
Jiushark’s JF800 Diamond is the best air cooler on the market that you can’t (easily) purchase. It outperforms its competitors in every thermal benchmark, even when the fans are noise-normalized. My only complaint is the lack of availability, at least in the U.S. If you want this amazing CPU cooler, you’ll need to import it from AliExpress or another Asian distributor, at least until there is better availability stateside.
