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The RTX 3090 is the ultimate consumer-grade graphics card you can get right now. 24 GB of GDDR6X memory, almost 10500 CUDA cores, working frequency of 1.7 GHz, PCIe 4.0 and HDMI 2.1 support crown the RTX 3090 as the ruler of the Ampere architecture. The 3090 is an extremely capable GPU that’s perfect for 4K gaming with max settings. A card as powerful as the RTX 3090 should be paired with powerful gaming CPUs.
The thing is, only a handful of current CPUs are capable of providing enough headroom without bottlenecking the RTX 3090. Luckily, our list of best CPUs for RTX 3090 builds contains just that. Blazing-fast gaming CPUs that have no trouble keeping up with the flagship Ampere GPU. We ended up with a diverse group of CPUs. We have top gaming processors but also productivity beasts. What we don’t have are budget gaming CPUs.
The 12th gen Core i9-12900K is the fastest gaming CPU at the moment and the best gaming CPU for the RTX 3090 overall. The 12900K beats every other CPU in games, even the behemoth that is the 5950X.
What’s even better for all you potential buyers is that the 12900K is also a beast when it comes to heavy multi-threaded work. The only type of workload where the 5950X regularly comes out ahead of the 12900K is rendering. The Alder Lake flagship trumps the flagship Zen 3 in everything else.
The cherry on top is that the 12900K is cheaper than the Ryzen flagship. Next, you don’t need a high-end Z690 board since even budget models can handle the 12900K without issues. With that said, the latest Core i9 does need a quality cooling solution since it seeps a ton of power (not in games, mind you) and can be pretty hard to cool.
Those who want to use the RTX 3090 for more than just gaming and are planning on building a powerful workstation machine should get a 3rd gen Threadripper. The Ryzen Threadripper 3960X will destroy any other processor in productivity loads and is the best CPU for the RTX 3090 when it comes to rendering, machine learning, and other work-related stuff RTX GPUs excel at.
You have 10K CUDA cores and 24GB of memory after all, the whole package selling at a relatively competitive price point compared to RTX Quadro GPUs. Games will run fine, especially if you’re planning to run them at 4K. Threadrippers are capable gaming CPUs. It’s just that they are too expensive to be found in gaming-exclusive machines.
Another good this is that the TRX40 chipset has full PCIe 4.0 support. Overall, pairing a Threadripper with the 3090 should make one hell of a productivity machine that can also run games better than most gaming PCs.
3. Intel Core i9-12900K: Best alternative to the Ryzen Threadripper 3960X
If you don’t have the cash for a Threadripper, get the Core i9-12900K. You’ll get the highest multi-threaded performance in a mainstream, general market CPU. Not as high as 3rd gen Treadripper models but fast enough even for professionals who make a living with their PC.
In games, however, the 12900K is far ahead of any Threadripper, as well as every Ryzen 5000 CPU. If you mostly play games and perform occasional video edits or renders but have extra cash for a Threadripper, save your money and go with the Core i9-12900K instead.
4. Intel Core i7-12700K: Best bang for the buck gaming and mixed-use CPU for RTX 3090
Yeah, we know that talking about bang for the buck with the RTX 3090 being a part of the conversation is flat-out comical, but still, if you want a fast and capable CPU but don’t want to splurge for the 12900K, get the Core i7-12700K. This is our recommendation for the best bang-for-the-buck CPU for RTX 3090 GPUs.
This CPU, at the moment, is massively cheaper than the 12900K while achieving about 98 percent of the 12900K’s gaming performance at 1080p. At 4K and 1440p, the 12700K will net you more than 99 percent of the 12900K’s performance.
The latest i7 is very close to the i9 flagship when it comes to multi-threaded workloads. Not as close for the 12900K not to make sense next to the 12700K but close enough for the lower price of the i7 to be very tempting when deciding between the two. After all, you can get both the CPU and a board for it for the cost of the 12900K.
And budget Z690 boards are more than fine for the 12700K. Next to the 5900X, the 12700K is a clear winner, both in games and multi-threaded work. The best thing is that the 12700K is cheaper than the Ryzen 9 part.
You can also save some cash on cooling that can go towards the RTX 3090 since the 12700K doesn’t ask for a beastly cooling solution like its bigger cousin. Even a capable single tower heatsink should do the trick, as long as you aren’t planning to overclock the CPU.
The 12700K would be a perfect fit for a PC used for gaming and streaming since it’s extremely fast in games while having enough performance left not to slow down games with OBS running in the background.
5. Intel Core i5-12600K: Best value gaming CPU for RTX 3090
Last but not least, we have the Core i5-12600K, which is the star of the show when it comes to the Alder Lake lineup. This relatively cheap CPU can achieve more than 95 percent of the 12900K performance in games at 1080p. In higher resolutions, the two are even closer.
In other words, the Core i5-12600K is the best value gaming CPU for RTX 3090 cards. Even when we talk about pairing it with the RTX 3090. The multi-threaded performance of the Alder Lake i5 part isn’t as impressive as its gaming prowess so if you plan on sweating all cores, get the 12700K or 12900K.
If you’re thinking about getting the 5600X over the 12600K, don’t. The 12600K is so impressive that it trades blows with the 5800X while leaving the 5600X in the dust, both in games and especially in multi-threaded workloads. In other words, the 12600K is a better choice than both the 5600X and 5800X.
The good news for the future 12600K owners is that the CPU doesn’t ask for an expensive cooling solution. If you’re planning on using it just for gaming, even a mid-range air cooler will do the trick. Finally, even a budget Z690 board will be more than enough for the 12600K.
What about older CPUs?
Since the RTX 3090 is the ultimate Ampere flagship card, we wouldn’t recommend running this card on anything less powerful than the Core i9-9900K or Ryzen 9 3900X, maybe Ryzen 7 3700X and Core i7-8700K.
You will probably see some bottlenecking taking place when pairing the card with the 8700K or 3700X, even at 1440p. But the number of frames lost due to the CPU shouldn’t affect the overall gaming experience.
How much faster is the RTX 3090 compared to the RTX 2080 Ti?
The RTX 3090 is about 10 percent faster than the RTX 3080 and about 35 percent faster than the 2080 Ti at 4K in games. When it comes to productivity well, those 24 gigabytes of GDDR6X memory and 10K CUDA cores will destroy any CUDA-related productivity benchmark.
If you’re interested in 3090 because you want to use it for more than gaming, you should expect a high enough performance increase to justify the high price of the card. The only issue is that driver support doesn’t include all productivity optimizations found on the RTX Titan, meaning that some workloads (CAD programs, for instance) won’t have the expected performance boost.
Does the RTX 3090 support PCIe 4.0, and will it work on a PCIe 3.0 motherboard?
Yes, the RTX 3090 supports PCIe 4.0. If you plan on getting the card and hooking it up to a PCIe 3.0 slot, don’t worry. The 3090 shows almost zero difference between PCIe 3.0 and PCIe 4.0, and you shouldn’t lose more than a couple of frames in games when hooking the card to the PCIe 3.0 x16 slot.
Does the RTX 3090 support HDMI 2.1, and will it work on older HDMI standards?
The RTX 3090 comes with full HDMI 2.1 support. However, the card will work fine on older HDMI standards. These older HDMI standards do pose some restrictions (they top out at [email protected], for instance).
It would be best to check which HDMI standard your monitor supports and then see which resolution and frame rate it can deliver in this handy HDMI guide. If you plan on using the RTX 3090 with a TV, make sure the TV includes HDMI 2.1 ports. As for gaming monitors, we recommend using DisplayPort instead of HDMI.