Virtu MVP: Lucid Logix Takes to Graphics Acceleration
Lucid Logix has also been doing some work to make Intel’s new platforms more attractive. The previous Z68 chipset for LGA1155 processors came along with Virtu technology that allowed using both the CPU-integrated graphics core and a discrete graphics card concurrently. This technology has progressed since then and Z77-based mainboards will support its next version called Virtu MVP. The graphics virtualization from Lucid Logix can work on older systems (and even on systems with AMD processors) but the marketing efforts will be focused on promoting Virtu MVP as a key feature of Intel’s 7 series chipsets and mainboards based on them. That’s why we’re going to discuss Virtu MVP in this review.
So, let’s see what Lucid Logix offers this time around. The point of the original Virtu technology was to provide access to the Quick Sync engine, which was part of Intel’s integrated graphics, on platforms with a discrete graphics card. Quick Sync helps transcode high-definition video at a very high speed, but the CPU-integrated graphics core is normally turned off when the system uses a discrete graphics card to output video signal to the monitor. Virtu solved this problem by allowing applications to access both the discrete and integrated graphics core without rebooting the system or reconnecting the monitor.
Virtu MVP takes the concept further. Instead of using either the integrated or the discrete graphics core depending on the specific task, both cores can now be used simultaneously. And while the CPU-integrated graphics was previously limited to multimedia tasks such as HD video decoding, Lucid Logix suggests that the different graphics cores can now be used together to achieve higher performance in games.
As a matter of fact, hybrid multi-GPU subsystems of this kind are quite a viable idea as was proved by AMD with its Dual Graphics technology implemented in systems with Llano processors. It really works and improves performance. However, a hybrid graphics subsystem is only going to be effective when the integrated and discrete graphics cores are more or less similar in computing power. Otherwise, the synchronization overhead may result in a lower frame rate compared to the single discrete solution.
Therefore Lucid Logix suggests using the resources of each core at different stages of the image rendering process. With Virtu MVP, a high-performance discrete graphics card is employed at the first and most resource-consuming stages: transformations, lighting, shader computations, primitives generation, projection transformation, rasterization, texture mapping, etc. The integrated graphics core, which has fewer resources, is only used as a frame buffer and is responsible for outputting the final image to the display.
Coupled with some undisclosed algorithms, which are Lucid Logix’s know-how, it helps implement two features that make games more responsive and improve their visual quality, at least theoretically.
- The first feature is called Virtual Vsync and it helps you get the benefits of both enabling and disabling Vsync in games. The point is that the image is delivered from the integrated graphics core’s buffer to the monitor in sync with the latter’s refresh rate. However, the discrete graphics card renders frames as fast as it can, as if Vsync is turned off. On one hand, this helps get rid of the Vsync-off artifacts like image tearing. And on the other hand, the frame rate is not limited from above, which helps minimize the game’s reaction lag which can be observed in some shooters when Vsync is turned on.
The left image shows an example of image tearing which can occur with Vsync turned off.
In other words, Virtual-Vsync produces the same image as with enabled Vsync but the frame rate is not fixed and can be either higher or lower than the monitor’s refresh rate.
- The other feature is HyperFormance. It helps increase the frame rate by not rendering those frames that never get to be displayed on the monitor. As far as we can make out from the rather vague explanation, HyperFormance works in two ways. First of all, the discrete graphics card does not do anything about frames that are identical to the image already being displayed on the monitor. The integrated graphics core’s frame buffer storing the image, the latter is just being output to the monitor until there are any changes in it. And second, some frames are not rendered because they would never be displayed on the monitor due to the latter’s limited refresh rate.
Combining these two tricks, HyperFormance promises a substantial increase in frame rate. Of course, this is a kind of cheat because the monitor won’t get any more frames per second to display. Moreover, the number of frames fully rendered by the graphics card doesn’t seem to increase, either. However, HyperFormance really helps make a game more responsive since it reduces the time lag between a user action like pressing a button or moving the mouse and the output of the next frame that shows the result of that action.
Thus, Virtu MVP finds more applications for the combined resources of integrated and discrete graphics cores than the original Virtu technology.
That’s the theory, though. As for the real applications, we got our apprehensions as soon as we saw the official test results for Virtu MVP. Here they are:
They show us the benefits of Virtu MVP using DirectX 9 games developed 4 or 5 years ago. Lucid Logix looks efficient, but hardly useful since it’s not possible to notice any acceleration with frame rates above 100 fps.
So, we carried out our own test of Virtu MVP using today’s games. The Virtu MVP technology is implemented by means of regularly updated software available for download from mainboard makers’ websites. The installation should go smoothly. You only have to make sure your mainboard supports Virtu MVP. It won’t work on incompatible models due to software restrictions because Lucid Logix receives license fees from mainboard makers.
After the installation, you launch a special tool to enable Virtual-Vsync and HyperFormance together or separately.
The utility offers an editable list of applications with individual settings. Considering that Virtu MVP includes the original Virtu functionality, you can also choose the primary graphics core for each application. Everything is intuitive and simple here.
We carried out five tests to check out the benefits of Virtu MVP: discrete graphics card without Virtu MVP but with Vsync turned on and off; Virtual-Vsync enabled; HyperFormance enabled; Virtual-Sync and HyperFormance enabled simultaneously. Here are the results:
3DMark 11 shows how Virtu MVP is supposed to work. HyperFormance provides a 40% performance boost here, but we know well enough that developers of new technologies optimize their solutions for popular benchmarks in the first place. What about games?
Virtual-Vsync works best among the Virtu MVP features: the frame rate goes higher than 60 fps, which is the refresh rate of our monitor, but there are no image tearing artifacts. However, the frame rate is lower than what you can get from the single discrete graphics card with Vsync turned off.
HyperFormance isn’t that consistent. We don’t always see the performance benefits promised by Lucid Logix. Moreover, it produces a lot of visual artifacts in textures, lighting and the image at large, so you just can’t play the game normally. It’s only in Metro 2033 and, with some reservations, in Battlefield 3 that we had decent image quality.
The developer must have intended HyperFormance to be used together with Virtual-Vsync. There are no image artifacts when you enable both concurrently. However, the frame rate proves to be almost always lower than when we use the discrete graphics card alone, with no Virtu MVP and with disabled Vsync.
Considering these results, we are inclined to view Virtu MVP as a more advanced version of Vsync. The combination of Virtual-Vsync and HyperFormance works correctly and often helps increase the frame rate compared to the conventional Vsync. So, if you regularly turn Vsync on in your games, you may want to use Virtu MVP to make them more responsive. Otherwise, the new technology from Lucid Logix is going to be rather useless for you. Virtu MVP can only provide the promised performance benefits in old, mostly DirectX 9, games which anyway run very fast on today’s graphics hardware.