|MSI Z77A-GD65 LGA1155 Motherboard|
|Reviews - Featured Reviews: Motherboards|
|Written by David Ramsey|
|Sunday, 08 April 2012|
Page 16 of 18
Lucid Virtu MVP
When the Sandy Bridge CPUs were introduced with the Cougar Point chipset family (P67, H67, etc.) there was a surprising limitation: you could choose a desktop system based on the P67 chipset, but that disabled the Sandy Bridge internal GPU. Or you could buy an H67 motherboard that enabled the GPU, but locked out overclocking features. In other words there was no way to use all of the capabilities of the CPU you'd purchased.
When the Intel Z68 chipset was introduced, motherboards built around it sported Lucid Virtu technology, a way to integrate the use of both the Sandy Bridge integrated GPU and a separate video card. Benchmark Reviews has an article describing the previous version of Lucid Virtu here. Virtu offered users the ability to make the most effective use of both the Sandy Bridge integrated GPU (iGPU) as well as a separate graphics card. Users could chose "Virtu i-mode", wherein the iGPU was the primary display mechanism, with the graphics card only being used when its performance was required, or "Virtu d-mode", in which the graphics card is the primary display mechanism, freeing the iGPU to drive a second monitor or be used for compute tasks like Intel's "Quick Sync" video transcoding.
At about the same time, NVIDIA announced their Synergy technology, similar to the Optimus feature that some notebook computers have been using for a couple of years. Like Virtu, Synergy would use the low-power integrated GPU for most tasks but seamlessly switch to the discrete graphics card under load conditions. Originally slated to be formally introduced in June 2011, nary a word has been heard from NVIDIA since the original announcement. In the meantime, Lucid's stepped up their game with Virtu MVP.
Virtu MVP is the latest iteration of Lucid's GPU virtualization software, and it expands on its predecessor's capabilities with two new features: HyperFormance and Virtual VSync. Let's take a look:
The main Virtu MVP control panel looks pretty much like the previous version. You can turn GPU virtualization on or off, and select whether or not you see a "Virtu" icon in games.
The "Performance" panel is where the new features are. HyperFormance "improves overall game performance and frame rate" while "Virtual VSync" lets users with enable VSync at rates otherthan 60FPS, a real benefit if you have a 120Hz monitor. The problem these performance features attempt to resolve is that your video card's frame rate rarely matches up to your monitor's refresh rate, especially in cases where the card can't generate enough FPS to make normal 60-FPS vsync feasible. Lucid's software trys to solve this by "Detecting, predicting, removing and replacing redundant rendering tasks, to enable the best visual quality with cleaner and smoother frames, and peak responsiveness."
Lucid has a white paper explaining HyperFormance and Virtual VSync in detail here.
So what does this mean to the game play experience? I ran two graphics benchmarks (both DX10 because that's all the iGPU of the i5-2500K supports) comparing the performance of the iGPU, Radeon 6850, and Lucid Virtu MVP with HyperFormance turned on and off. The results were amazing.
With the Lucid Virtu version shipped with Z68 motherboards, I saw about a 3%-7% frame rate hit. This made sense because Virtu has to copy each rendered frame from the video card's frame buffer to the iGPU frame buffer in main memory. And in the Heaven benchmark, with HyperFormance turned off, there's a 3.68% drop in frame rate. But with HyperFormane turned on, the frame rate increases by 14%
In 3DMark Vantage, the HyperFormance increases are huge: 60% in the Jane Nash test and 63% in the New Calico test. How does Virtu MVP accomplish this?
I've read through Lucid's white paper, and as best I can determine the way HyperFormance works is to elminate "redundant frames", which Lucid defines as frames that wouldn't be shown completely because they would be interrupted by a monitor refresh interval. In these cases render of the redundant frame is aborted and the time that would have been spent rendering it is devoted to the next frame. You'd think this would result in some jerkiness in the displayed images, but I didn't see any, so I guess Lucid's onto something.
This makes the HyperFormance benchmark scores understandable: of course you can get more FPS if some of the frames are simply displayed multiple times, rather than each frame being a unique render. So while the effect may be that of a higher FPS, you're not really seeing the same thing you'd see if the video card could actually generate that many FPS. Futuremark has already announced plans to upgrade 3DMark to detect Virtu and provide a more realistic frame rate result. However, I can report that visually, I didn't see anything amis and the perceived performance was definitely better with HyperFormance turned on...which is of course the whole point.