What is the best CPU for the RTX 4090?

We all know that the 4090 is an absolute unit, but what CPU do you need to fully support it?

Updated: Nov 17, 2022 3:36 pm

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Nvidia has released the RTX 4090 to the world, its official release date being October 12th, 2022. And with it being the single most powerful GPU in the world, it needs some pretty hefty hardware to support it. So what is the best CPU for the RTX 4090? 

Now read: RTX 4090 review 

**UPDATE** – intel 13th gen is here and the 13900K is now the obvious choice for the best CPU for the RTX 4090. You can find links to buy below:

Here we will run through a few CPUs we think would be a great pairing with the newly released RTX 4090, we have chosen CPUs from both team red and team blue, to keep everyone happy. 

Here’s where to buy the RTX 4090, in case you were looking to pick one up.

What makes a powerful CPU?

First of all, let’s establish the factors at play that make a CPU “powerful”. CPUs are very complex chiplets, so most of the things we will be touching on here are just the tip of the iceberg. And explained in the simplest form we can manage.  

Core and thread count

Core and thread count is possibly the most important metric that attributes to CPU power. As the more cores and threads a CPU has, the better it will be at multitasking. 

Multitasking is important because there’s a lot going on in your modern-day PC, the CPU has to process complex instructions, and feed other components information they need to run and delegate their resources properly. A CPU has millions of responsibilities to fulfill every second. So it’s important your CPU is able to keep up. 

Core speed

CPU core speed is another important point of consideration, as a CPU’s cores speed determines how fast it can perform the CPU instruction cycle. Or more accurately, how many times it can complete that instruction cycle every second. 

When the CPU instruction cycle is completed, an instruction is executed. A modern-day CPU has to execute billions of these instructions every second just to stay ahead, so the faster the CPU’s core, the more of these instructions it can chew through every second. 

IPC

Instructions per clock, or IPC, is a different measurement from core speed but it is somewhat interlinked. IPC is linked to the nm process of each CPU, meaning the size of the transistor inside the CPU. 

Transistors are basic Yes/No logic gates that can be combined to process more complex instructions. The size of the transistor matters as smaller transistors can be packed into the same space in greater numbers, upping the processing power and instructions per clock of the CPU. 

The smaller the nm process, the better the CPU. If we’re talking about a level playing field. If a CPU has a larger nm process but more cores and threads, then it’s likely going to win over the CPU with the smaller nm process. 

The best CPU for the RTX 4090

We’re going to outline the best from AMD and Intel, obviously. You need a powerful CPU that’s going to keep the 4090 fed, all the while keeping up with its own list of responsibilities. 

You’re going to want a beefy CPU to be able to keep up with the demand of owning a 4090. This GPU is incredibly hungry and will chew through any load even the most modern CPU can feed to it. You’re definitely best off not scrimping on a CPU, as it’s highly likely you’ll run into a CPU bottleneck, even when going for a CPU lower than the flagship on the latest generation.

Intel Core i9-13900K

The i9-13900K is a very powerful CPU capable of destroying the competition, Its 24-core and 32-threads dominate in both single and multi-core workloads. cementing the 13900K at the top of multi-threaded performance for the first time in years.

The 13th-generation Raptor Lake CPUs see improved single-core performance of up to 15% and multi-core performance of up to 41%. The best part is you don’t even have to upgrade your motherboard to access all of this performance, but upgrading has its benefits.

Ryzen 9 7950X

The Ryzen 9 7950X is a beast in its own right, just like the RTZ 4090. This CPU has 16-cores and 32-threads with a maximum boost clock all the way up to 5.7GHz giving it some pretty mean single-core performance. 

The new Ryzen 7000 series is also built upon the new 5nm architecture. Giving it much higher IPC increases over the previous gen. 

Ryzen 9 7900X

The Ryzen 9 7900X is not all that different from the 7950X in terms of IPC or core speed. But it does only have 12-cores and 24-threads. Making its multi-core performance pack much less of a punch. 

Obviously, it’s much less expensive. But if you’re looking at what CPU to pare with a 4090, money probably isn’t an issue. This CPU will still see you through just fine. 

i9-12900K

Here we have the i9-12900K, the 12900K is one of Alder Lakes’ top dogs, it’s a 16-core, 24-thread beast capable of feeding the best GPUs on the market. Its huge 5.2GHz boost speed is nothing to wince at either. 

Selecting this CPU ensures you’ll be able to do it all. Built on the Intel 7 architecture for a 12nm manufacturing process of Intel’s own design.  

i7-12700K

The 12700K is probably the lowest we’d go when pairing a CPU with an RTX 4090. The i7-12700K has a total of 12-cores and 20-threads. 

Its max boost frequency also hits 5.0GHz, ensuring that you can still just about support the RTX 4090 without impeding the CPUs performance in other tasks. 

Should I upgrade my CPU for the RTX 4090?

That all depends on what CPU you happen to have now.

Final Word

So there we have it, four CPUs suited well to the RTX 4090 and many more on the way on team blue. There are also the X3D models on the horizon from AMD, but you’ll have to wait until the start of 2023 for those.