We decided to study the system performance in 3D games with Lucid Virtu technology and without it, i.e. in i-Mode, d-Mode and with Virtu completely off. We used a discrete Radeon HD 6970 graphics card. We set 1920x1080 resolution in all tested games and used only maximum image quality settings.
The numbers speak for themselves. Enabling Virtu causes the gaming performance to drop in any case. However, in d-Mode, where discrete graphics accelerator plays the dominant part, the fps rate drops only by a few percents and is, actually, barely noticeable. Things get much worse in i-Mode. The speed drops substantially in some games because of the need to additionally transfer the rendered images along the PCI Express bus. And, frankly speaking, i-Mode seems to be totally unacceptable for gamers because it doesn’t allow you to get the best of your graphics sub-system.
However, could our opinion about the i-Mode and d-Mode change after the transcoding speed test? To answer this question we checked how fast the system could transcode a 3 GB 1080p movie in H.264 format (a 40-minute TV show episode) into lower resolution for viewing on an iPhone 4. We performed transcoding using popular commercial utilities supporting Intel Quick Sync technology: Cyberlink MediaEspresso 6.5.1704_37777 и ArcSoft MediaConverter 22.214.171.124.
Here Lucid Virtu technology works impeccably. Transcoding speed is hardly affected by enabled Virtu neither in d-Mode, nor in i-Mode. Systems with Virtu take about the same time to transcode as systems with integrated Intel HD Graphics 2000/3000 core. So, due to the use of Intel Quick Sync Virtu really can significantly speed up HD video transcoding in
However, there is also the third aspect – power consumption. Let’s see what will happen to this parameter when we enable Virtu, especially, since the developer – Lucid – promotes the i-Mode as an optimal solution for users who care about energy-efficiency.
It is obvious that Virtu technology cannot lower the power consumption of a system equipped with a discrete graphics accelerator to the level of an integrated LGA1155 platform. As for the energy-efficiency of the advertised i-Mode, it only shows during video transcoding or playback or at the expense of a catastrophic performance hit. In all other cases we didn’t see any noticeable improvement. The reason for that is because the discrete graphics accelerator is never fully off even in i-Mode: even though it may be idle, it is still powered on. As for 3D modes with enabled Virtu technology, the discrete graphics card is used in exactly the same way as during its normal gaming operation, and the alleged energy savings are only achieved at the expense of performance.
So, i-Mode is in fact of pretty limited interest, because it lowers the 3D performance considerably, but doesn’t really offer any advantages in return, with the exception of some energy savings in several specific cases, like during HD video playback or transcoding. d-Mode, however, looks much more appealing. The 3D performance losses here are minor, but video transcoding is performed via Intel Quick Sync allowing to take real advantage of this technology even with a discrete graphics card in the system.