Subject: General Tech | April 18, 2013 - 01:46 PM | Ken Addison
Tagged: vsync, vertex 3.20, podcast, pcper, overclocking, ocz, haswell, gtx 780, GLOBALFOUNDRIES, gigabyte brix, frame rating
PC Perspective Podcast #247 - 04/18/2013
Join us this week as we discuss Frame Rating and Vsync, the future of GLOBALFOUNDRIES, the OCZ Vertex 3.20 and more!
The URL for the podcast is: http://pcper.com/podcast - Share with your friends!
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Hosts: Ryan Shrout, Jeremy Hellstrom, Josh Walrath, and Allyn Malventano
Program length: 1:07:41
0:01:08 Win the Roccat ISKU Keyboard
Week in Review:
News items of interest:
Jeremy: support Full Control not just because they're nordic
Allyn: (portable headsets that don't suck)
1-888-38-PCPER or firstname.lastname@example.org
Subject: Graphics Cards | April 16, 2013 - 03:01 PM | Ryan Shrout
Tagged: vsync, stutter, smoothness, microstutter, frame rating, animation
We are running a poll in conjunction with our Frame Rating: Visual Effects of Vsync on Gaming Animation story that compares animation smoothness between fixed 30 FPS and 60 FPS captures and Vsync enabled versions.
If you haven't read the story linked above, these questions won't make any sense to you so please go read it and then stop back here to answer the polls!
Not a simple answer
After publishing the Frame Rating Part 3 story, I started to see quite a bit of feedback from readers and other enthusiasts with many requests for information about Vsync and how it might affect the results we are seeing here. Vertical Sync is the fix for screen tearing, a common artifact seen in gaming (and other mediums) when the frame rendering rate doesn’t match the display’s refresh rate. Enabling Vsync will force the rendering engine to only display and switch frames in the buffer to match the vertical refresh rate of the monitor or a divisor of it. So a 60 Hz monitor could only display frames at 16ms (60 FPS), 33ms (30 FPS), 50ms (20 FPS), and so on.
Many early readers hypothesized that simply enabling Vsync would fix the stutter and runt issues that Frame Rating was bringing to light. In fact, AMD was a proponent of this fix, as many conversations we have had with the GPU giant trailed into the direction of Vsync as answer to their multi-GPU issues.
In our continuing research on graphics performance, part of our Frame Rating story line, I recently spent many hours playing games on different hardware configurations and different levels of Vertical Sync. After this time testing, I am comfortable in saying that I do not think that simply enabling Vsync on platforms that exhibit a large number of runt frames fixes the issue. It may prevent runts, but it does not actually produce a completely smooth animation.
To be 100% clear - the issues with Vsync and animation smoothness are not limited to AMD graphics cards or even multi-GPU configurations. The situations we are demonstrating here present themselves equally on AMD and NVIDIA platforms and with single or dual card configurations, as long as all other parameters are met. Our goal today is only to compare a typical Vsync situation from either vendor to a reference result at 60 FPS and at 30 FPS; not to compare AMD against NVIDIA!!
In our initial research with Frame Rating, I presented this graph on the page discussing Vsync. At the time, I left this note with the image:
The single card and SLI configurations without Vsync disabled look just like they did on previous pages but the graph for GTX 680 SLI with Vsync on is very different. Frame times are only switching back and forth between 16 ms and 33 ms, 60 and 30 instantaneous FPS due to the restrictions of Vsync. What might not be obvious at first is that the constant shifting back and forth between these two rates (two refresh cycles with one frame, one refresh cycle with one frame) can actually cause more stuttering and animation inconsistencies than would otherwise appear.
Even though I had tested this out and could literally SEE that animation inconsistency I didn't yet have a way to try and demonstrate it to our readers, but today I think we do.
The plan for today's article is going to be simple. I am going to present a set of three videos to you that show side by side runs from different configuration options and tell you what I think we are seeing in each result. Then on another page, I'm going to show you three more videos and see if you can pinpoint the problems on your own.
AMD and Virtual Vsync for Lucid Virtu
Lucid has grown from a small startup that we thought might have a chance to survive in the world of AMD and NVIDIA to a major player in the computing space. Its latest and most successful software architecture was released into the wild with the Z68 chipset as Lucid Virtu - software that enabled users to take advantage of both the performance of a discrete graphics card and the intriguing features of the integrated graphics of Intel's Sandy Bridge CPU.
While at Computex 2011 in Taiwan we met with the President of Lucid, Offir Remez, who was excited to discuss a few key new additions to the Virtu suite with the new version titled "Virtu Universal". The new addition is support for AMD platforms including current 890-based integrated graphics options as well the upcoming AMD Llano (and more) APU CPU/GPU combinations. It is hard to see a reason for Virtu on current AMD platforms like the 890 series as there are no compelling features on the integrated graphics on that front but with the pending release of Llano you can be sure that AMD is going to integrate some of its own interesting GP-GPU features that will compete with the QuickSync technology of Sandy Bridge among other things. To see Lucid offer support for AMD this early is a good sign for day-of availability on the platform later this year.
The second pillar of Lucid's announcement with Virtu Universal was the addition of support for the mobile space, directly competing with NVIDIA and AMD's own hardware-specific switchable graphics solutions. By far the most successful this far has been NVIDIA's Optimus which has filtered its way down basically into all major OEMs and in most of the major notebook releases that include both integrated and discrete graphics solutions. The benefit that Lucid offers is that it will work with BOTH Intel and AMD platforms simplifying the product stack quite a bit.
Read on for more information and some videos of Virtual Vsync in action!
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