ASUS P8Z77-V Premium Review: A Bentley Among Motherboards

Gaming Benchmarks: A note on Multi GPU and PLX PEX 8747

In an upcoming review, we will go into detail regarding the PLX PEX 8747 chip on motherboards.  This chip allows the manufacturers to adjust lane counts between PCIe slots, and increase bandwidth between PCIe slots at the expense of added latency to the CPU.  Normally the Z77 chipset is limited to x8/x4/x4 in multi-GPU setups, but with the PLX chip this is expanded, such that x8/x8/x8/x8 in PCIe 3.0 is available.  There is more under the hood than this, especially relative to performance, but it is important to note for this review and results where we are comparing many setups.  Out of the boards we have tested, the configurations are below. 

In general:

PCIe 3.0 > PCIe 2.0
Lanes from CPU > Lanes from PLX > Lanes from Chipset
More lanes > Less lanes

Civilization V

Civilization V is a strategy video game that utilizes a significant number of the latest GPU features and software advances.  Using the in-game benchmark, we run Civilization V at 2560x1440 with full graphical settings, similar to Ryan in his GPU testing functionality.  Results reported by the benchmark are the total number of frames in sixty seconds, which we normalize to frames per second.

Civilization V is unfortunately a bad game to see scaling with our 7970 cards, especially as we are locked in with our drivers during our Z77 testing.  At each test, the Premium scores above 70 FPS, but falls a little in single GPU testing compared to others hitting 80 FPS.

Civilization V scales a little bit better on NVIDIA cards, giving a near top Z77 result in single mode, but is middle of the pack in dual GPU mode.

Dirt 3

Dirt 3 is a rallying video game and the third in the Dirt series of the Colin McRae Rally series, developed and published by Codemasters.  Using the in game benchmark, Dirt 3 is run at 2560x1440 with full graphical settings.  Results are reported as the average frame rate across four runs.

Dirt 3 loves GPU power, and it is not until we hit three GPUs where the difference in lane counts come into play.  In our three-GPU testing, the Rampage IV Formula gets 194.55 FPS, the Premium is 193.55 FPS and the GA-Z77X-UD5H is 183.51 FPS.  The latter two have similar CPU speeds but differ on lane count, giving the Premium an extra 10 FPS.

Not much to say for Dirt 3 + NVIDIA testing, all the motherboards perform roughly the same.

Metro2033

Metro2033 is a DX11 benchmark that challenges every system that tries to run it at any high-end settings. Developed by 4A Games and released in March 2010, we use the inbuilt DirectX 11 Frontline benchmark to test the hardware at 2560x1440 with full graphical settings.  Results are given as the average frame rate from 4 runs.

In Metro 2033 + AMD, all the motherboards perform similarly in single and dual GPU mode, but at tri-GPU mode the Premium takes almost a 1 FPS advantage over the nearest challenger.

With Metro 2033 + NVIDIA, all the motherboards perform similarly in single and dual GPU.