Application Profiling Tells the Story
It should come as no surprise to anyone that has been paying attention the last two months that the latest AMD Ryzen processors and architecture are getting a lot of attention. Ryzen 7 launched with a $499 part that bested the Intel $1000 CPU at heavily threaded applications and Ryzen 5 launched with great value as well, positioning a 6-core/12-thread CPU against quad-core parts from the competition. But part of the story that permeated through both the Ryzen 7 and the Ryzen 5 processor launches was the situation surrounding gaming performance, in particular 1080p gaming, and the surprising delta that we see in some games.
Our team has done quite a bit of research and testing on this topic. This included a detailed look at the first asserted reason for the performance gap, the Windows 10 scheduler. Our summary there was that the scheduler was working as expected and that minimal difference was seen when moving between different power modes. We also talked directly with AMD to find out its then current stance on the results, backing up our claims on the scheduler and presented a better outlook for gaming going forward. When AMD wanted to test a new custom Windows 10 power profile to help improve performance in some cases, we took part in that too. In late March we saw the first gaming performance update occur courtesy of Ashes of the Singularity: Escalation where an engine update to utilize more threads resulted in as much as 31% average frame increase.
As a part of that dissection of the Windows 10 scheduler story, we also discovered interesting data about the CCX construction and how the two modules on the 1800X communicated. The result was significantly longer thread to thread latencies than we had seen in any platform before and it was because of the fabric implementation that AMD integrated with the Zen architecture.
This has led me down another hole recently, wondering if we could further compartmentalize the gaming performance of the Ryzen processors using memory latency. As I showed in my Ryzen 5 review, memory frequency and throughput directly correlates to gaming performance improvements, in the order of 14% in some cases. But what about looking solely at memory latency alone?