Conclusion
In today’s CPU performance and comparison review we took the high-end CPUs from Intel and AMD and put them head-to-head in a fight to see who is best at a competing MSRP price point. In this review, we compared the Intel Core i9-12900K versus AMD Ryzen 9 5900X in synthetic benchmarks, and games at 1080p, 1440p, and 4K. The Intel Core i9-12900K represents Intel’s fastest 12th Gen Alder Lake CPU product stack currently. At $589 RCP it competes by price with the AMD Ryzen 9 5900X with an MSRP of $549.
To this date, we have evaluated the Intel Core i5-12600K and Intel Core i7-12700K and compared them against the competing products. In both reviews, the new Intel 12th Gen CPUs have come out on top in benchmarks and gaming performance, especially at 1080p. They have proven to be faster at multi-threading and single-thread performance over the AMD equivalents. We, therefore, wanted to see if this trend continued with the Intel Core i9-12900K.
The Intel Core i9-12900K versus AMD Ryzen 9 5900X is an interesting proposition because both CPUs can work on 24 processor threads. They have the same thread count support. However, they get there in two very different ways. The Ryzen 9 5900X has a standard approach with 12 high-performance cores capable of multi-threading providing 24 threads. However, the Intel Core i9-12900K has a hybrid approach, with 8 Performance Cores and 8 Efficiency Cores, where the Performance Cores are the only ones with HyperThreading, giving it 16+8 threads for a total of 24, but 8 of those threads are handled by the Efficiency Cores. The 12900K is configured as a 16 Core (8P+8E) 24/Thread CPU.
Another aspect that does separate the two CPUs greatly is the power limit and the max frequencies. The Intel 12900K is allowed to hit 241W (or even above on certain motherboards settings by default.) Whereas the 5900X has a TDP of 105W but does hit above that around 140W. Intel is allowing this high power range to hit the 5.2GHz max turbo boost frequency on the 12900K. The 5900X can only boost to 4.8GHz, and then not on all cores. The Performance Cores on the 12900K can hit up to 5.1GHz and the Efficiency Cores up to 3.9GHz which are powerful Comet-Lake’eque performance in their own right.
Synthetic and Rendering Performance
The Intel Core i9-12900K started off strong in the system benchmarks with PCMark 10 performing 8% faster with the 12900K versus the Ryzen 9 5900X. This performance delta widened in the Applications Benchmark which tests actual Microsoft Office performance. The 12900K was 12% faster than the 5900X, meaning people that work on MS Office heavily or use it on a daily basis will see a performance uplift on the new 12900K CPU.
In 3DMark CPU Profile test, we looked at Max Threads and 1-thread testing. The Max Threads testing is interesting since both CPUs can work on 24 threads. That said, the 12900K still beat the 5900X by 14%! The single-thread test also proved to be strong for the 12900K putting it 11% faster than the 5900X. Geekbench 5 backed up the fact that the 12900K is faster in multi-threading and a single-thread. In multi-threading, in Geekbench the 12900K was a whopping 37% faster. In single-thread it was 14% faster. In PassMark PerformanceTest the 12900K was overall 11% faster than the 5900X.
Next up we tested SiSoftware Sandra 2021 in its Dhrystone (Arithmetic) and Whetstone (Floating-Point) testing in multi-threading and single-thread. In the Arithmetic multi-threading performance, the 12900K beat the 5900X by 19%, and in single-threading beat it by 10%. The tables turned in the Multi-Media Whetstone testing, however, where the 5900X came out on top in multi-threading by 14% and in single-thread by 4%. We did test with the “Big Cores” on the 12900K in the single-thread testing. It appears the 12900K is very good at arithmetic and maybe falls behind the 5900X on pure floating-point, but it’s still very close on single-thread.
AIDA64 showed us how crazy the 12900K on DDR5 can be with 81GB/s of memory read bandwidth and 74GB/s of memory write performance. This was 40-50% better than the 5900X on memory bandwidth. Looking closely at cache bandwidth and latency was also interesting. The 5900X seems to have better latencies all around, but the cache bandwidths change places. It’s at least good to see the L3 cache problems with the Ryzen CPUs is fixed in Windows 11.
In Cinebench R23 the 12900K was 29% faster than the 5900X, and some people will live and die by that result alone. It’s certainly impressive, considering both CPUs are 24 thread CPUs. On single-thread testing, the 12900K was 23% faster than the 5900X. The rendering goodness continued in Blender with the 12900K saving us 10% render time, rendering the scene faster. This was also shown in V-Ray where the 12900K was 14% faster than the 5900X. HandBrake was a shocker, we saved a good 26% off the time transcoding video.
Gaming Performance
To get a good feel for gaming performance we tested 7 games at 1080p, 1440p, and 4K so that you can see where the benefits are. We used a fast GeForce RTX 3080 Ti. By far 1080p showed the highest differences, and they were pretty much consistent, every game at 1080p proved to be faster on the 12900K over the 5900X. Forza Horizon 5 was 5% faster, Battlefield 2042 was 7% faster, Cyberpunk 2077 was 2% faster, MS Flight Sim was 6% faster, Far Cry 6 was 15% faster, Watch Dogs was 16% faster and Crysis Remastered was 9% faster. Some of those performance improvements are significant for just a CPU causing an uplift in gaming performance.
What surprised us, even more, was that in some games we even saw performance benefits at 1440p. In Forza Horizon 5 the 12900K was 5% faster, in Flight Sim, it was 6% faster, in Far Cry 6 it was 15% faster, in Watch Dogs it was 8% faster, and in Crysis Remastered it was 9% faster. We didn’t expect percentage differences this high at 1440p, yet here it is. That means those playing at 1080p and 1440p, which are two of the most common resolutions for gaming could see an uplift in performance with the 12900K and a fast GPU versus the 5900X. Once you get to 4K though, you are GPU bound and it’s not going to matter unless you play at lower graphics settings.
Power and Temp Summary
One of the primary concerns with the 12900K is the idea that it pulls a lot of power and demands extreme cooling producing high temperatures. Well, this isn’t just an idea, our data proves it to be true, but also, it depends. The type of workload you are making the CPU do will actually determine if it’s a power hog and gets hot. With a maximum turbo power of 241W, it has the capability and potential of going there for sure, but it may not in all workloads.
In our Cinebench R23 10-minute testing we pushed the CPU to maximum usage for 10-minutes. In this scenario, where all cores are being pushed as hard as possible we found that the CPU Package Power did indeed get up to 251W of power, while the 5900X was only at 140W. This resulted in the temperature hitting 93c maximum while the 5900X stayed at a cool 61c. The T-Junction is 100c on the 12900K, so it wasn’t throttling at this temp, but still, ouch. Keep in mind this is with an MSI MEG CORELIQUID S360 AIO 360mm Cooler at the maximum pump and fan speeds. If you had a smaller AIO or lower fan speeds, then, I’d be worried if you were going to run your CPU at max usage like this a lot.
However, we don’t always run our CPUs at max usage. If you are playing a game, for example, your CPU will not be doing as much work, all cores will not be engaged at full-throttle. We proved this with your gaming test, Cyberpunk 2077 for 10-minutes. The 12900K’s CPU Package Power dropped to just 125W matching the 5900X. At that level of power demand, the CPUs were equal on power, and this made the temperatures tolerable. The 12900K was now only 63c from 93c before.
Therefore, doing something like playing a game has a similar power and temp comparison to the 5900X. This would also extend to things like office work, Microsoft Office, and other desktop workloads. However, if you are one that is going to run your CPU at max utilization because you transcode video, export video, render 3D animation, or do other content creation tasks like these, then you may see high power and high temps.
If you know your CPU is going to be maxed out frequently, you want nothing less than a 360mm AIO with the 12900K, and I’d still tune my fans to high-performance mode. If, however, you are mainly going to be gaming with your 12900K, you could get away with a lower fan speed 360mm AIO, or even a 280mm AIO on performance-fan mode.
Final Points
The Intel Core i9-12900K is fast, darned fast. It can outperform an AMD Ryzen 5900X despite having the same 24 process thread support. It will outperform it on multi-threading applications and especially where single-thread performance is preferred over multi-threading. The high clock frequency on the 12900K is highly beneficial for single-thread or lesser-thread workloads, like gaming. The clock speed makes a big difference.
Now, the truth is Intel is pushing the CPU pretty hard to get that clock speed and performance. It’s no secret, it is going to demand a lot more power, which means you want a quality power supply with a high-wattage supply, motherboards with quality VRMs, and you also want quality cooling. You will typically need a larger AIO with the 12900K, ideally 360mm. Then there is DDR5. All of these factors upscale the cost to move to 12900K.
This is where the Ryzen 9 5900X has positive points. It has a lower cost of entry. Motherboards based on X570 have been out a while now, and are more moderately priced. In addition, you can still use the cheaper and more abundant DDR4. Plus, you do not need an exotic cooling device. All of this can save you money on a 5900X platform. However, it is also a platform at the end of its life. AMD will be moving to socket AM5 motherboards when Zen 4 is released. Whereas Alder Lake does have some wiggle room for future growth.
No matter which one you pick, you won’t be disappointed. Just be prepared to build your system right for the Intel Core i9-12900K, keep the power demand and high temperatures in mind for your build. Use a large quality AIO, make sure the case has plenty of airflow, get a good motherboard and PSU, and you should be fine. In that case, you’ll find the 12900K to offer a tremendous amount of performance in pretty much everything it will beat the 5900X, and that’s just darned impressive.