NVIDIA GeForce RTX 4000-series graphics cards continue the legacy of RTX 3000-series GPUs in terms of power consumption and size, while the performance has been improved by around 40 to 50%. The graphics cards' prices have also increased, especially for the flagship models, even though there is no mining craze going on right now. Most previous-generation graphics cards on the market are available at dirt-cheap prices. In this article, we will be checking the best CPU for RTX 4090.

NVIDIA GeForce RTX 4090 is the company’s flagship graphics card based on the Ada Lovelace architecture. There is a big difference in performance compared to the previous-generation flagship, as there is a whopping core count of 16384 in the RTX 4090. Moreover, this is the first graphics card with 512 texture mapping units and 192 render output units. The clock rates have also been drastically increased from the previous generation, with the base clock set at 2235 MHz and the boost clock set at 2520 MHz.

Intel Core i9-13900K The Overclocker's Dream Intel Core i9-13900K Read More See On Amazon
AMD Ryzen 9 7950X The Threadripper Killer AMD Ryzen 9 7950X Read More See On Amazon
AMD Ryzen 9 7900X The Powerhouse of Multitasking AMD Ryzen 9 7900X Read More See On Amazon
Intel Core i9-12900K The Gamer's Delight Intel Core i9-12900K Read More See On Amazon
AMD Ryzen 9 5900X The Productivity King AMD Ryzen 9 5900X Read More See On Amazon

On the other hand, the graphics card’s memory is a bit similar to the RTX 3090 Ti, as it uses a 384-bit wide memory bus in combination with a 24 GB memory buffer. The overall memory bandwidth of the graphics card is 1018 GB/s, which is almost the same as the RTX 3090 Ti, whose memory bandwidth was 1008 GB/s. Overall, there are no noticeable improvements in the graphics card’s memory from the previous generation. Now, when you buy a graphics card like RTX 4090, you have to have a processor that can drive such a beast of a graphics card. Right now, both Intel and AMD are giving tough time to each other, as Ryzen 7000-series processors and Intel’s 13th-generation Core i-series processors are released. AMD is leading the market this time with its jaw-dropping power-efficient architecture, while Intel is leading the whole value thing.

For a graphics card like RTX 4090, you have to pair it with a flagship processor, which brings us to the likes of Ryzen 9 7950X and Intel Core i9-13900K. The Ryzen 9 processor comes with sixteen cores, while the Core i9 comes with twenty-four cores. The overall performance of processors on platforms is similar, which drives the debate about motherboards.

AMD Ryzen 7000-series processors can be used with the latest B650 and X670 chipset motherboards, while the Core i-series processors can be used with the existing Z690 or the all-new Z790 chipset motherboards.

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Best CPU for RTX 4090 Reviews

Intel Core i9-13900K

Intel Core i9-13900K

The Overclocker's Dream

  • +Fastest in the gaming CPU market.
  • +Support for DDR5 and PCIe 5.0 standards.
  • +Excellent performance/price ratio.
  • High power consumption.
  • May not be compatible with your existing motherboard.

Coming at an MSRP of $589, the Intel Core i9 13900K is the fastest gaming processor and the best deal in terms of price-to-performance ratio. It features 8 performance cores, with clock speeds ranging from 3-5.8 GHz, and features multithreading. The rest of the cores are known as efficiency cores and are 16 in number and are single threaded. The clock speeds of these cores range from 2.2 GHz to 4.3 GHz. In terms of cache memory, the processor features an L2 cache, sized at 32MB, and a 36MB L3 cache. All this sounds fine and dandy. So, where’s the catch? Well, there are a few things you might be better off forewarning beforehand.

First, the processor comes with a very strong thirst for power (pun intended) with its minimum requirement of 125W, which can roughly double to 253W when utilized to its fullest extent. You will need a pretty sizable PSU (750W or more) and a powerful cooler (the box doesn’t come with any), preferably an LCS, to dissipate all that excess heat efficiently.

Second, the processor is only compatible with motherboards featuring the LGA 1700 socket. So, if you are only planning on upgrading your processor, check for any compatibility issues with your existing motherboard.

The third point is not as much a warning as a tip to save some extra bucks. Although the processor comes with support for the DDR5 RAM standard, the truth is there are very few mid-range motherboards that support it. Plus, the RAM sticks themselves are very expensive. And despite the massive prices, the performance addition could be more pronounced. So, if you stick with the typical 16GB 2400MHz DDR4 RAM stick, you’d be good to go.

It is important to avoid bottlenecks when building a PC by keeping everything balanced. For example, even if your processor sends too few instructions for rendering, the GPU will always remain underutilized even if you have a powerful GPU. For this reason, the i9-13900K is the best processor you can use alongside the RTX 4090 to use each component fully.

AMD Ryzen 9 7950X

AMD Ryzen 9 7950X

The Threadripper Killer

  • +Excellent overall performance.
  • +Support for DDR5 and PCIe 5.0.
  • Not the best bang for the buck.
  • Doesn’t support DDR4.
  • No stock cooler.

The AMD Ryzen 9 7950X, with an MSRP of $699, is AMD’s flagship processor, based on its latest Zen 4 architecture. The architecture is based on the cutting-edge 5nm process, resulting in significant performance-per-watt improvements over its predecessors.

The processor has a base clock speed of 4.5 GHz, which can be “boosted” up to 5.7 GHz. It has 16 cores and 32 threads, resulting in great single-core and multi-tasking performance. L2 Cache size has also been doubled to 16MB from its predecessor 5950X’s 8MB.

Unlike Intel, AMD is in no hurry to shift toward hybrid architecture. So, there won’t be any processor resource allocation issues for Windows 10 users who go with the Ryzen 9 7950X instead of the i9-13900K. This is because the hybrid architecture is still developing, and sometimes resource-intensive tasks get allocated to efficiency cores which can affect performance. However, if the users upgrade their OS to Windows 11, they can use Intel’s Thread Director tool, preventing such issues from arising.

With a TDP of 170W, going all the way to 230W for heavy loads, it is natural to expect to die temperatures hovering around ~90C at most times below the 95C safety threshold set by AMD. AMD suggests we go with a 240-280mm LCS, but we’d say spend a few extra bucks and go for the 360mm one and save yourself any headaches.

In our gaming test alongside the RTX 4090, the 7950X maintained an average of 75 FPS in CyberPunk 2077 at QHD settings, which is excellent. For the rendering tasks, we used Blender’s OpenData utility to benchmark our processor and got a score of 600, a considerable lead over the i9-13900K’s score of 569. So, there is no doubt that it is one of the best CPUs to utilize RTX 4090’s highest potential fully.

Should you go with AMD for the next processor upgrade you planned for? Why not if money is not a problem? However, for prudent buyers, value-wise, Intel makes a much stronger proposition with its i9-13900K offering similar performance at a significantly lower price point.

AMD Ryzen 9 7900X

AMD Ryzen 9 7900X

The Powerhouse of Multitasking

  • +Brilliant performance.
  • +Support for DDR5.
  • Doesn’t support DDR4.
  • DDR5 and motherboards supporting it are quite expensive.
  • Box doesn’t come with a stock cooler.

The Ryzen 9 7900X, based on AMD’s latest Zen4 architecture, is one of AMD’s higher-end offerings in the CPU market. It comes with an MSRP of $549, which is reasonable for its performance. The processor features 12 cores and 24 threads and can touch a maximum clock speed of 5.6GHz. It also features AMD’s iGPU integrated graphics for typical day-to-day tasks or troubleshooting in case the discrete card fails.

With such high price and performance figures, it is unsurprising that it also comes with a minimum TDP of 170W, which can go all the way to 230W if pushed too hard. This means that the typical die temperature remains above ~80C, and below 95C is safe, according to AMD. The box doesn’t come with any stock cooler. We recommend an LCS cooler for the 7900X, preferably a 360mm one, such as the Corsair H150i Elite, to keep noise and temperature levels low.

Our performance test is two-part: gaming and rendering. For the first one, we ran CyberPunk 2077 at 1440p settings and got an average frame rate of 60 FPS, a bit lower than the 71 FPS we got with i9-12900K, which is not much more expensive at $589. For rendering, we used the Blender Benchmark tool and got a score of 458 compared to the i9-12900 K’s score of 400, a considerable lead for AMD in this test.

So, what’s our verdict on this processor? Well, we don’t have any complaints when it comes to the performance of this processor. On its own, it is a very good processor to couple with the RTX 4090 without any issue of underutilization. However, the devil is in the details, as they say.

The processor only works with DDR5 RAM, and these RAM sticks and the motherboards that support them will burn a large hole in your pocket if you choose to go with this processor but won’t offer humongous performance gains. Since the comparably priced i9 13900K performs similarly, we will only push you to buy this processor after all is said.

Intel Core i9-12900K

Intel Core i9-12900K

The Gamer's Delight

  • +Excellent performance.
  • +Great value for money.
  • +Supports both DDR4 and DDR5.
  • Box doesn’t come with a cooler.

Coming at an MSRP of $589, the Core i9 12900K is one of the most competitive price, high-performance processors that Intel has released recently. It is based on the Alder Lake architecture, the successor to Rocket Lake, and features 16 cores and 24 threads. Following the ARM processors' footsteps, the cores are divided into performance and efficiency categories to allocate processor resources suitably, resulting in enhanced performance and power efficiency.

The processor supports DDR4 and DDR5 standards, unlike its rival, which only supports DDR5. The performance (or P) cores run at clock speeds ranging from 3.2-5.2 GHz, while the E cores run between 2.4 and 3.9 GHz. However, this transition towards hybrid architectures is still bumpy, as the operating system also plays an important role in task allocations to processor cores. Most users are still using Windows 10, so they will only partially benefit from this change because it needs to work properly with the new architecture. Intel has released the Thread Director to fully use the hybrid architecture by appropriate resource allocation, but it only works for Windows 11.

And now, onto our performance benchmarks. In CyberPunk 2077, we got a stable frame rate of 71 FPS while running the game at the moderately high settings of 1440p. In the Blender Benchmark tool, after multiple image renderings were performed, our CPU produced a score of 380, beating its rival Ryzen 5900X’s score of 340, which can become significant in terms of time saved when huge workloads are involved. Based on these numbers, it is one of the best processors for RTX 4090.

So, what are our final thoughts on this processor? Based on our analyses, this is a great deal for high-end users who don’t want their expensive $1000+ graphics card underutilized because of a slow processor. The one flaw of this processor, patchy support for hybrid architecture in Windows 10, will be fine since users upgrading their processors will probably upgrade their OS, too.

AMD Ryzen 9 5900X

AMD Ryzen 9 5900X

The Productivity King

  • +Excellent performance in gaming and productivity tasks.
  • +Twelve cores and twenty-four threads are enough these days.
  • +PCIe 4.0 support for high-speed storage and graphics cards.
  • +Energy efficient with 105W TDP.
  • +Compatible with the latest AM4 motherboards.
  • Slightly expensive as compared to other mainstream processors.
  • Requires a high-end cooling solution as it lacks the bundled cooler.
  • Lacks integrated graphics, so you must need a dedicated GPU.
  • Availability issues due to high demand.

The AMD Ryzen 9 5900X is based on AMD’s Zen 3 architecture. With AMD already releasing processors based on Zen 4 architecture, the 5900X seems slightly dated. It comes with an MSRP of $549, and the marked absence of freebies like CPU coolers suggests that long gone are the days when AMD used to be a value champion. The processor features 12 cores and 24 threads and an L3 Cache of 64MB. The base clock speed is 3.7GHz, which can increase to ~4.8GHz under heavy loads. The thread and core counts and great clock speeds resulted in excellent overall single- and multi-task performance.

The processor does not have integrated graphics, which is a shame. Although for a processor in this price range, the purchase of a dedicated GPU is already assumed, integrated graphics can still be quite helpful in troubleshooting your PC if the discrete card is not working. However, we won’t get too obsessed with this issue. To explain the absence of a stock cooler, AMD says that above a TDP of 65W (5900X has a TDP of 105W), most buyers will buy a custom cooler anyways, which makes the stock cooler an unnecessary addition.

The gaming performance of the Ryzen 9 5900X was excellent when we played CyberPunk 2077 at 1440p settings with our RTX 4090 graphics card. The average frame rate was recorded at 68 fps resulting in a buttery-smooth playing experience. In the rendering test, our Ryzen 9 5900X scored 319 after several images were rendered with the Blender Benchmark tool, compared to $488 i9-10900K’s 260, Intel’s closest rival processor to 5900X.

So, what do we feel about the 5900X after all is said and done? Well, this processor comes with only some of the flaws we found in the other AMD options we discovered in this list, such as supporting only DDR5 RAM resulting in additional charges to optional customers, but mandatory instead. The performance figures are also quite solid especially compared to its rival. Therefore, its inclusion in our list of Best CPUs for Nvidia RTX 4090 is quite justified.

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Umar Farooq
Umar Farooq

Umar Farooq has developed a passion for computers ever since the time his father brought home the first family computer in 2002, a time when broadband internet was still in its infancy and almost every PC component was at least an order of a magnitude less powerful than the typical ones available today. Recently, he decided to start writing on this website to help tech rookies not be too enticed by overly hyped marketing terms they barely understand and get the best deal for their money.

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