If you’re someone who spends more than $1,000 on high-end GPUs, you probably expect a huge performance boost in every game you play after each update. I mean, that’s the whole point of spending on something like an RTX 4090 or 5090, right? You’re not just chasing higher frame rates; you also expect your games to be smoother and more responsive, especially if you’re gaming on a 240Hz or 360Hz monitor. But if you’ve ever upgraded your GPU just to enjoy the FPS boost, you’re not alone.
I’m having this issue as someone who’s paired an RTX 4090 with a 5800X3D. Before we get to the results, this CPU was one of the best options on the market when Nvidia launched the card in 2022. Of course, at 4K it’s not a big deal unless I’m playing competitive games, but at 1440p the CPU limitations can’t be ignored. Likewise, you can pair the 9800X3D with an RTX 5090 and still use the GPU less often than you might expect. And that’s what I want to talk about here.
High-end GPUs are CPU-limited even at 1440p
The reason your 240Hz or 360Hz monitor isn’t fully utilized is your CPU
While we think flagship GPUs like the RTX 4090 and 5090 are for 4K gaming, many competitive gamers are pairing them with 1440p ultra-high refresh rate monitors. On paper, this makes sense, as you have more than enough GPU power to easily push 200 FPS to take advantage of fast-paced titles. But where exactly is this CPU limits kick in and your GPU is underutilized. Even if you have the fastest CPU, you’ll often see your GPU usage drop well below 90% at these frame rates.
Even if you have a CPU like the 9800X3D, it’s not worth your money to go after high-end GPUs for 1440p gaming. Take the RTX 5090 for example. According to benchmarks, it’s about 12% faster than the RTX 4090 on average at 1440p. That’s nowhere near the 27% jump you get in 4K. And that gap is a result of CPU limitations, so all that extra GPU horsepower just doesn’t translate into real-world performance gains. You’re paying for performance your current CPU can’t unlock.
Even competitive gaming at 4K still reveals CPU limitations
The RTX 5090 shines in AAA games, but CPU-related titles tell a different story
There’s no doubt that most modern games tax GPUs so hard at 4K that you’ll need a high-end card like an RTX 4090 or 5090 to maintain playable framerates unless you want to rely on upscaling or framerate generation. In such situations, your GPU does exactly what you pay for, which is to push the visuals as far as possible while maintaining stable performance. But this only applies to AAA titles that are naturally GPU-hungry, so CPU doesn’t matter that much. You can even away from using a CPU several generations ago and still get similar results.
This changes completely even in competitive games at 4K. The moment you start chasing higher frame rates instead of visual fidelity, your CPU becomes more important than most people expect. These games are designed to run at 200 FPS or more, which means the GPU often has a lot of leeway while your CPU struggles to keep up. When I play competitive titles like I do Assessment and Counter-Strike: 2my RTX 4090 usage rarely goes above 80% at native 4K when paired with the 5800X3D, which tells you all you need to know about where the bottleneck actually is.
Most gamers don’t chase very high frame rates
But for those who do, even the best CPUs aren’t enough
You could argue that most gamers don’t play at 200+FPS and I totally get that. The vast majority of people who buy an RTX 4090 or 5090 are primarily playing AAA games at 4K, where the GPU does most of the heavy lifting. In these games, you rarely get more than 100 FPS unless you have upscaling or framerate anyway, so even a few-year-old CPU won’t noticeably affect its performance.
But there are people like me who enjoy the game with high refresh rate. After all, 240Hz and 360Hz OLEDs are popular these days for a reason. The moment you step into that area, You are not limited by how fast your GPU can render framesbut with how fast the CPU can go. Sure, you can get the fastest CPU available today to minimize potential bottlenecks, but even then, you’ll run into scenarios where the GPU isn’t fully utilized. At this point, you’re just sitting there wondering why you opted for a 1440p/360Hz monitor and an advanced GPU when your CPU can handle everything.
CPUs need to mature so that GPUs can lean towards 4K without relying on it
We’ve gotten to the point where throwing more GPU horsepower at a game won’t automatically translate into a better gaming experience, especially if you’re not playing in 4K. At 1440p and higher refresh rates, the CPU decides how much of that performance you’ll actually use. So how well CPUs should be able to keep up with flagship GPUs not only in raw performance, but also in different gaming scenarios. Until that happens, I don’t think even the RTX 6090 will help gamers get the most out of their ultra-high refresh rate monitors.
