Intel Z68 Chipset Review: dGPU and iGPU living together, SSD Caching and Overclocking

Multi-Display Testing and Lucid Virtu Performance

As one of the two key new features on the Z68 chipset, switchable graphics is worth spending some time on.  Yes, we have already previewed the Lucid Virtu software in a previous article, and unfortunately came away from that experience wanting a bit more.  A bit cleaner interface, a bit better performance, a bit better overall experience.  This time around we have the final 1.0.0 version at our disposal that fixes some things and even offers the ability to run your display off either the integrated or discrete graphics (previously it was integrated only).

While Intel has finally enabled users to enable both integrated and discrete graphics on an enthusiast class system, I find it interesting that they are dependent on third parties like Lucid and NVIDIA to provide the software to make this a good user experience.  Without Virtu or the upcoming NVIDIA Synergy having both graphics enabled would without a doubt confuse the consumer that tried using them – either gaming performance would be well below expected (if using the Sandy Bridge processor graphics) or features like Quick Sync wouldn’t function (if using discrete).  Intel usually either keeps these options unavailable or likes to perfect themselves before letting them out in the wild so it would appear that Intel is putting a lot of stock in the likes of Lucid and NVIDIA.

Multiple Displays – Use Case #1

The most basic use case of having a switchable graphics solution is to provide additional video outputs over and above the ones provided by a discrete graphics solution.  Though AMD’s latest graphics cards can supply 3 displays at the minimum, the third requires a DisplayPort connection that very few monitors are using today and thus 2 might be the limit for your average consumer.  NVIDIA’s cards (with the exception of the GTX 590 and a few boutique configurations) are also limited to two monitors per card.  Using the Z68 chipset would allow the consumer to run display off of whatever connections the motherboard provides as well.

Here you can see I have attached a single monitor to the dual-link DVI output on the GTX 285 graphics card as well as one to the ASUS P8Z68-V Pro motherboard’s DVI output.  The result is a system that can properly see both graphics cards, both drivers and operate on them smoothly, as long as you are running Windows 7.

While driver control panel compatibility is always a question mark, in this case both the latest NVIDIA and Intel GPU drivers are working side by side (literally) without any problems.  

This functionality can exist WITHOUT the need for Virtu or Synergy running in the background (just like you could with the H67 chipset) though you are going to have issues either getting your games running at the full speed of your discrete graphics or running applications that take advantage of Quick Sync, etc.  Which one will work correctly will depend on your BIOS settings and often times which GPU the OS decides to attach to first.  With either switchable graphics software though, the idea is that you can get the best of both without the trouble of switching back and forth.

Gaming Performance – Use Case #2

Installing the Lucid Virtu software is about as easy as it gets – it is a small piece of software that requires a reboot to get working.  After that, enabling and disabling it is as simple as right clicking on an icon in your task bar and switching them back and forth. 

The software interface remains unchanged from our earlier look and could definitely use some refinement but the functionality is there.  Notice the motherboard is listed at the bottom of the application window, an indicator that your board is properly detected by the Virtu software and is enabled correctly. 

Here you can see all of the games and applications that Lucid has tested and enabled to work with Virtu out of the box.  These applications have profiles that will enable them to run on the discrete GPU by default rather than on the slower processor graphics.  The good news is that if your game isn’t listed or a new title is released before Lucid has the chance to release updated software, you can simply hit the Add button and find the executable file to include it on this list. 

While we don’t recommend keeping the icon there permanently, seeing it placed on the screen when your application is running on the discrete GPU can help with troubleshooting and to make sure that your game is properly recognized by the software and that the "switch" in the switchable graphics is working in your favor.

To test Virtu yet again with this 1.0 release, we decided to use the same processor test bed but move the primary display output from the discrete card to the integrated graphics DVI port.  Originally, this was a REQUIREMENT of Virtu but has since been altered.  Let’s see how the performance of having the discrete-only setup compares to that of a Lucid Virtu switchable configuration.

While the 3DMark Vantage results look basically identical between the GTX 285 and the Virtu configuration, the F1 2010 and Left 4 Dead 2 results show a slight performance drop.  More than likely due to the latency introduced when moving frames from the discrete GPU to the main system memory frame buffer for the Intel Sandy Bridge graphics to output, this drop was the reason Lucid worked to find a way to support connecting the display to the discrete card.

Intel Quick Sync – Use Case #3

Obviously the next thing to test if Lucid Virtu enabled us to take full advantage of Intel’s HD Graphics 3000 features while utilizing the gaming performance of the discrete GPU.  For that we fired up a copy of the CyberLink Media Espresso application that allows us to use the Quick Sync video transcoding feature for incredibly fast video transcoding. 

Here you can see our result for transcoding a large 1080p video file from a Canon 7D camera to a format compatible with the Apple iPad; 23 seconds is pretty good for this conversion.

In this screenshot you will see the time of 44 seconds that is the result seen when utilizing the discrete graphics on the GeForce GTX 285 and the best hardware acceleration that it can provide.  At about 90% slower than the Intel integrated graphics hardware you can see why users were eager to be able to include this kind of acceleration in their computing landscape.

Finally here we see the results while using the Lucid Virtu software, in the same boot session as getting the much improved gaming performance of the GTX 285.  You can see the 23 seconds here matches the performance we saw with the integrated-only configuration. 

Obviously there are still some questions on the long term viability of this and other desktop switchable graphics software solutions.  We are a bit confused as to why NVIDIA has delayed the release of its Synergy software that was mentioned in our material and even in BIOS’ of several motherboards we have been testing so it appears obvious that NVIDIA had planned on pushing this out today.  Hopefully we’ll get hands-on with it soon so we can compare it to what Lucid has been able to provide with Virtu and maybe see some additional features added to this list.