How Does PCI-Express Speed Impact Gaming Performance
Surfing around I found this article that looks at the impact of PCI Express speed and your video card. As some of you know I have the "Multi GPU Index" as a dedicated page in my motherboard reviews that basically maps out the PCI Express layout and suggested GPU configurations.
When I started the "Multi GPU Index" the intent was to settle the question on where users should install their video cards and rank motherboards based on expansion slot layout and PCI Express bandwidth. Those calculations were based on PCI Express bandwidth and the question came up, "is the Multi GPU Index still valid?"
The short answer is, yes. Despite the bandwidth increases with PCI Express 3.0 I still use the 2.0 standard to do the calculation. This makes things easier and puts more focus on overall layout then pure bandwidth.
Many hardware sites (such as TechPowerUp and AnandTech) have shown in the past that most video cards do not show any performance decrease by running in x8 mode and cannot utilize the larger bandwidth provided by the latest Gen3 specification. However, video cards are getting faster and faster so we felt it was worth revisiting to find out if the fastest video cards available still do not have any performance advantage running at PCI-E x16 Gen3 versus PCI-E x8 Gen2. In addition, multiple GPU setups has not been throughly tested and with the gaining popularity of 4k displays, we felt it was important to see if the PCI-E revision/speed would affect a dual GPU setup at the much more demanding 4k resolution.
PCI Express 3.0 has the benefit of bandwidth and the only reason their 16x vs 8x tests are valid is because current games no longer saturate the buss. This is why AMD was able to ditch the Crossfire connection on the R9 290X and why future versions of GPU hardware will likely follow suit. It is an exciting time for hardware enthusiasts and I can't wait to see real world 4K results.
Related Web URL: http://www.pugetsystems.com/labs/articles/Impact-o...
