How Much RAM do You Need for An RTX 4090?

The RTX 4090 is undoubtedly the king of NVIDIA’s modern day graphics cards. Packed with over 16,000 CUDA cores, and 24GB of GDDR6X RAM, this beast of a GPU is truly monstrous in any game you throw at it. And with monstrous specs, and enough VRAM to put most modern day gaming PC’s to shame, one question is likely to pop up: "Just how much RAM do I need to run the RTX 4090?"

Fortunately, gaming RAM is one of the products that we specialize in here at CORSAIR, and that puts us in a unique position to be able to tell you exactly how much you might need to get the most out of your GPU, and push those 4K gaming frame rates to the max.

Recommended RAM Requirements

NVIDIA’s RTX 4090 is mostly platform agnostic at this point. You could theoretically place it in a system with an Intel Core i5-2500K and 16GB of DDR3 RAM if you really wanted, and, as long as you had a sufficiently sized power supply to support it (850W minimum dependent on system specs, find our full range of CORSAIR PSUs here), gaming with it would work just fine, albeit at a far reduced performance level.

That said, when you invest in a flagship like this you’re going to want it to get the most out of it 100% of the time. Nothing beats hitting 100 fps with 4K gaming. To do that, having the right RAM working in tandem with a solid processor is going to be key. The last thing you want is your $1,500 RTX 4090 gaming GPU bottlenecked by an aging processor and slow RAM.

The Memory Sweetspot

So then, 16GB, 24GB, 32GB, 48GB? DDR4? DDR5? Which RAM is right for you and your new RTX 4090? To get the most out of your 4K gaming experience and beyond, you’re going to want a minimum of 32GB of DDR5 RAM.

This is considered the absolute sweetspot right now for gaming systems, and should future-proof you for the coming years, especially if you’re gaming at higher resolutions and beyond on the latest AAA titles. You can read more about that here.

4K textures take up a significant amount of RAM, and once that capacity is all used up on your RTX 4090, your system will then start storing those files onto your rig’s dedicated gaming RAM instead. This is alongside running the game, and any and all programs you might have in the background as well.

Processor + Gaming RAM = More Frames

Likewise, it’s good to have an understanding of how your processor operates with your RAM too. When your RTX 4090 is generating frames, it’s in constant communication with your processor. As the CPU performs calculations, reacts to your inputs, and acts on game-code, it then feeds that all back to the GPU, which then outputs the frame. It then either stores it in its local VRAM (or sends it back to be stored in your system RAM), or outputs it to your monitor. The thing is, depending on the title, it can do this well over 100x a second in some cases, and that takes a lot of processing power from your CPU. When your CPU can’t keep up, frame-rates will drop as your RTX 4090 becomes bottlenecked. This is where good quality fast gaming RAM can help.

AMD processors in particular, thanks to their design, benefit from higher-speed memory, and particularly DDR5 with EXPO memory profiles, as it allows the processor’s cores to communicate faster with one another, speeding up performance, in some cases by 10-15%. This can help alleviate some bottlenecks, or generally improve performance in top end processors, leading to more frames in game.

TL;DR?

You want at least 32GB of DDR5 for your RTX 4090. If you’re running an AMD processor that supports EXPO profiles, make sure you pick up a kit with the correct profile timings. And if you’re looking for long-term longevity, 64GB of DDR5 is a pretty good place to start.

Lastly, you can place an RTX 4090 in a system with an older processor and DDR4 memory, however you may be limiting its performance, if the CPU or even memory become a bottleneck in game, particularly at lower-resolutions.

Check out the full range of CORSAIR DDR5 memory for more information.