I recently built a PC with a Ryzen 7 9800X3D, Radeon RX 9070 XT, 32 GB of DDR5-6000 CL30 memory, and a 1440p 240 Hz monitor. In CS2, I average around 300–350 FPS with drops to about 200. My brother's PC has the same CPU and RAM but an RTX 4070, a 1080p 165 Hz monitor, and averages roughly 500–600 FPS.
I played stretched 4:3 at 1280×960 on both systems, used the lowest settings, enabled EXPO, and confirmed that the DisplayPort cable is connected to the graphics card. Changing between 1280×960 and 2560×1440 barely changed my FPS. Drivers and Windows are up to date, and I do not have significant background applications running.
My CPU also reaches about 95°C during Cinebench multicore, while my brother's reaches around 78°C, although our scores are similar. Neither system is overclocked or undervolted. Could the monitor or resolution explain the FPS difference, or is there something else I should check?
4 Answers
Since changing resolution barely affects performance, this is probably not mainly a GPU or monitor-resolution limitation. CS2 may be CPU- or game-thread-limited, so compare the exact graphics settings, launch options, drivers, BIOS settings, and power plans on both systems. Also verify that EXPO is actually running at 6000 MT/s with the expected timings.
Check that Windows has not replaced or layered its own display driver over the AMD driver. A clean reinstall using the current Radeon driver can help. It is also worth updating the motherboard BIOS and AMD chipset drivers, then checking that the game is actually using the RX 9070 XT rather than an unexpected graphics device.
You can test with the Vulkan launch option, although it does not improve performance on every system. Since you already saw similar FPS at 1280×960 and 2560×1440, focus more on frametime graphs, CPU clocks, temperatures, and per-core utilization than on the monitor’s refresh rate. A 240 Hz monitor does not by itself reduce FPS.
The CPU temperature deserves a physical inspection. Around 95°C in an all-core Cinebench run can be normal for a modern Ryzen chip, especially if the benchmark score is normal, but make sure the cooler is mounted evenly and the mounting brackets or standoffs are oriented correctly. Uneven contact can let the CPU reach its temperature limit even with a good cooler.
The cooler’s protective film was removed, and the system is otherwise stock. I may still remount it to verify the contact and thermal paste application.
I checked the settings and both systems were using the lowest settings. EXPO is enabled and memory is running at 6000 MT/s.