I'm running Windows 11 on an ASRock B660M-C motherboard with an Intel Core i5-13400F, an AMD Radeon RX 9070 XT with 16 GB of VRAM, and 16 GB of system memory. Most games run reasonably well, but performance is lower than I expected compared with benchmark videos. In Cities: Skylines II, I average around 30 FPS at 1440p on High settings. Lowering the settings to Medium only raises that to about 35 FPS, and dropping to 1080p reaches roughly 45 FPS. I'm wondering whether the CPU, memory, or another component is limiting performance, and what upgrades would make the biggest difference without replacing the graphics card.
3 Answers
Before buying anything, monitor CPU usage by core, GPU utilization, RAM usage, temperatures, and clock speeds while playing. If the GPU is well below full utilization while one or more CPU cores are maxed out, you’re CPU-bound. If RAM usage is close to full or the system is paging, upgrade to 32 GB. Also compare benchmarks using the same city size, mods, game version, and settings—performance can vary dramatically in this game, so claims of 100 FPS on High aren’t universal.
Cities: Skylines II is heavily CPU-limited, especially once the city gets larger. Since lowering resolution barely changes the frame rate, your RX 9070 XT probably isn’t the limiting part. A faster CPU could help, but the improvement depends on the city size and simulation load. On that B660 board, check CPU support and BIOS requirements before considering an i7 or i9, and make sure the board and cooler can handle the extra power.
The first upgrade I’d make is increasing the RAM from 16 GB to 32 GB, ideally with a matched dual-channel kit. Also make sure XMP is enabled in the BIOS. That may improve stuttering and minimum FPS, but it probably won’t turn Cities: Skylines II into a 100-FPS game.
That explains why changing from 1440p to 1080p barely helped. If the CPU is busy handling the simulation, reducing GPU settings won’t produce a major FPS increase.