Cities: Skylines II is a game that runs slower than any other game we’ve tested this year. Playable frame rates are out of reach even with the most expensive GPUs. At 4K, not even the mighty GeForce RTX 4090 hits 30 FPS, while the Radeon RX 7900 XTX struggles with an average of under 17 FPS. The rest scramble to maintain double-digit averages.
We tested Cities: Skylines II using a Core i9-13900K on an ASUS ROG Maximus Z790 Hero motherboard. The system was paired with 32GB QC memory clocked at 6000MT/s and a Corsair RM1000E. The CPU was cooled using a Lian Li Galahad 360 AIO liquid cooler.
At 4K, it’s bloody murder, even for the fastest GPUs on the planet. The GeForce RTX 4090 hardly manages to cross the 20 FPS mark with lows of 8 FPS. AMD’s RDNA 3 flagship, the Radeon RX 7900 XTX slugs it out at 17 FPS with lows of just 5 FPS. The RX 7900 XT chokes under 14 FPS with a 1% low average of 4.5 FPS. The GeForce RTX 3080 Ti is an inch slower, with an average of 13 FPS.
The frametime graph indicates that none of the GPUs offer a playable experience. However, the RTX 3080 Ti and the RX 7900 XT are particularly stuttery, with spikes of over 400ms. Interestingly, the frametime variance graph shows that the RTX 3080 Ti is overall smoother than the RX 7900 series.
At 1440p, the fastest Radeon and GeForce cards overcome the 30 FPS mark with lows of 17 and 15 for the RTX 4090 and RX 7900 XTX. The Radeon RX 7900 XT nets 25 FPS, while the RTX 3080 Ti comes in with 23 FPS, on average. Once again, the latter has higher lows than the former.
The Radeon cards continue to struggle at 1440p, with multiple frametime spikes of over 100ms. The GeForce RTX 4090 is the smoothest, followed by the RTX 3080 Ti.
At 1080p, most modern GPUs are expected to deliver playable frame rates. Cities 2: Skylines is an exception. The RTX 4090 and the RX 7900 XTX both average above 40 FPS with lows of 20+ FPS. The RX 7900 XT and its Ampere rival cross the 30 FPS threshold but are limited to single-digit lows.
The frametime variance is a repeat of the first two tests, with the GeForce RTX 4090 finishing first and the Radeon RX 7900 XT coming in last.
Cities II: Skylines is a massive city simulator, and such titles tend to be CPU-bound. However, it’s so poorly optimized that the GPU is continuously hammered, leaving the CPU, with plenty of breathing room. Below, you can see the GPU-busy times at 1080p using an RTX 3080 Ti and an RTX 4090.