Why Does Dota 2 Seem to Use Only One CPU Core on My Ryzen 3950x?

Question

XpL0d1ngN3m3s1s - April 15, 2025

I’m running Dota 2 on a Ryzen 3950x CPU, RX 6800 GPU, and 96 GB of RAM. When I start playing, I get high frame rates—around 250+ FPS on low settings. However, after about 30 minutes, my FPS drops drastically to around 50+. I checked Task Manager and it looks like the game is only using one logical CPU core. I also tried switching from DirectX 11 to Vulkan, but Vulkan caused more stuttering instead of improving performance. Has anyone else experienced this or know why Dota 2 might be limited to one core despite having a powerful multi-core system? Any fixes or explanations would be appreciated!

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4 Answers

Answer 1 · 2025-04-15 14:28:22

One thing you might want to look into is your RAM configuration. Having dual rank RAM sticks and ensuring your RAM has a high clock speed can help guarantee smoother frame times and better minimums, which might prevent those big FPS drops over time. It won’t solve the single-core CPU usage fully but could improve overall stability during longer sessions.

Answer 2 · 2025-04-15 09:45:13

Switching to Vulkan might cause stuttering if the drivers aren’t fully optimized for your GPU or if the game’s implementation is still rough. Sometimes DX11 runs smoother on certain hardware setups even if Vulkan theoretically should be better. If Vulkan stutters more for you, sticking with DX11 is probably the way to go until things improve.

Answer 3 · 2025-04-15 07:35:35

The FPS drop after a while could also be related to game memory leaks or engine inefficiencies rather than just single-core usage. Sometimes, despite your hardware being beefy, the Source engine has issues with prolonged play sessions causing stuttering or FPS drops. For now, your best bet is to keep graphics settings low and maybe try monitoring background processes that could be throttling performance.

Answer 4 · 2025-04-15 02:17:27

This is pretty typical for games on the Source engine like Dota 2. They tend to rely heavily on strong single-core performance rather than spreading the workload efficiently across multiple cores. So even on a powerful CPU like the Ryzen 3950x, the game might mostly run on one core, which limits how well it can use your hardware. That’s why you see the CPU stuck at one logical core doing most of the work.