After the CPU and GPU, the memory (RAM) is the most important component of a gaming PC. People often cheap out on the memory, only concerning themselves with the module capacity, ignoring the speeds and latency. Like the CPU, memory bottlenecks are subtle and can adversely affect your gaming performance. The average frame rates aren’t affected by much, but the lows and frame pacing often take a severe hit, leading to FPS drops and jittery gameplay, essentially ruining your experience.
In Intel’s monolithic chips, the difference is relatively less pronounced, but in the case of the Ryzen 3000 CPUs, it can have a major impact on gaming performance. This is because of the Infinity Fabric connecting the various chiplets. It runs at around 1800MHz, so if you use a memory kit slower than that, it’ll scale down to the same speed, inducing a latency between the various CCDs.
The IF fabric runs either at the same frequency as the RAM or at half the speed. The former is preferred.
- CPU: AMD Ryzen 9 3900X
- GPU: NVIDIA GeForce RTX 2080 Super
- Memory: Trident Z Royal 8GB x 2 @ 3600MHz
- PSU: Corsair HX1000i
In this post, we have a look at the impact of memory speed on gaming performance in the case of the Ryzen 3000 processors. We’ll also briefly see how much the memory timings affect the frame rates and whether they’re more important.
The average frame rates in a game give a relative measure of overall performance. They don’t account for the lags or FPS drops (if any) and as such can be misleading at times. 90th and 99th percentile are used in tandem with the averages to make up for that shortcoming. The higher their values, the better the overall performance:
- Average: This represents the average frame rate through the benchmark run.
- 90th percentile: 10 frames out of 100 are slower than this frame rate. 90% of the frames will achieve at least this frame rate.
- 99th percentile: 1 frame out of 100 is slower than this frame rate. 99% of the frames will achieve at least this frame rate.
Impact of Memory Speed on Gaming Performance: Ryzen 9 3900X
All the games were tested at the highest in-game preset at 1080p with the memory timings set to 16-16-16-36:
Other than Metro Exodus, all the games see a healthy boost going from 2400MHz to 300MHz. However, the uplift to 3600MHz is relatively less attractive with even the memory-intensive Assassins’ Creed Origins gaining just 3 FPS on average. The lows, however, still see a sizeable improvement.
What About Latencies?
There’s a lot of confusion regarding latencies. Most people aren’t even sure what the memory timings or latency refer to. We won’t explain it here. If you want info on that, we did a detailed post on it a while back:
For this test, we’ll compare Dual Channel Memory Running at 3600MHz and 3000MHz. Then, we’ll reduce the latency (lower is better) of the latter and see how much of a difference does it make, and whether low-timings are better than higher frequencies:
In Assassins’ Creed, there’s almost no difference. In fact, the lows fall slightly. Ashes Escalation, on the other hand, gets a marginally improved average and identical lows. I suspect, 16-16-16-36 is the sweet spot and below that there’s very little you can gain. Furthermore, after this point, you should focus on increasing the memory frequency over reducing the timings. We’ll do a more detailed piece on the impact of memory timings on gaming performance, stay tuned!