Podcast #392 - Samsung 850 EVO V2, VR Build Guides, the End of Tick-Tock, and more!

Subject: General Tech | March 24, 2016 - 01:47 PM |
Tagged: western digital, VR, vnand, vive, video, Samsung, podcast, Oculus, hgst, He8, CRYORIG C7, 8tb red, 850 EVO

PC Perspective Podcast #392 - 03/24/2016

Join us this week as we discuss the Samsung 850 EVO V2, VR Build Guides, the End of Tick-Tock, and more!

You can subscribe to us through iTunes and you can still access it directly through the RSS page HERE.

The URL for the podcast is: http://pcper.com/podcast - Share with your friends!

Hosts: Ryan Shrout, Jeremy Hellstrom, Josh Walrath, and Allyn Malventano

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March 24, 2016 | 02:44 PM - Posted by funandjam

Where is the link for the YT video?

March 24, 2016 | 03:23 PM - Posted by Ryan Shrout

In the post now, sorry!

March 25, 2016 | 02:40 AM - Posted by Anonymous (not verified)

You might be overthinking what is needed to run at 45 fps on a VR headset. You might not be able to do interpolation since the next frame would not be available unless you are already running with an extra frame of latency. I would think that would be bad at 45 fps. What you can do is just take the current frame and move it on the screens based on the users head movement.

When we are talking 90 fps, the amount of head movement for each frame is usually very small. Moving the current frame to fill in an extra frame would just shift a small amount of new area in on the edge of the frame and shift a small amount of area off the screen on the other side: basically, you scroll it. I don't know what would be best to fill in the area which hasn't been rendered; maybe just fill with black.

This isn't going to be the best quality compared to real 90 fps, especially if your in game character is moving, since that motion would not be present in the added frame. I don't know if it would be worthwhile to try to update the added frame other than attempting to correct for the users head movement.

March 25, 2016 | 10:30 PM - Posted by Photonboy (not verified)

You can't simply "shift" the entire frame to create a new artificial frame.

For example, a ball might be travelling to the LEFT and a car might be travelling to the RIGHT. The ball would have to continue a bit more to the left whereas the car would have to continue to the right.

When HDTV's do this they have to analyze several frames to account for acceleration of objects then shift all the pixels accordingly.

It also is impractical because it adds a lot of latency. It's fine for sports videos because it's not interactive but useless for gaming/VR.

If you DID shift the entire frame slightly it wouldn't be noticeable, or if you shifted it too much then the video would not look right at all. It just doesn't work.

March 27, 2016 | 04:02 AM - Posted by Anonymous (not verified)

Yes, you would introduce some judder in moving objects. It would correctly update the frame for the users head movement though, except for objects moving in the frame. Updating for the users head movement is probably more important than introducing motion artifacts in objects moving within the frame. I don't know how much judder would be introduced at 45/90 fps, or how noticable it would be. It would depend on the scene; the amount of motion, contrast of the moving object, size of the moving object, etc. They also may be able to do some minimal processing to reduce judder, but this will produce some artifacts. You probably can't avoid some artifacts without rendering a new frame. At 60/120, judder from moving objects may not be noticable at all though.

For 45 fps, they would, at a minimum need to do frame doubling where they just show the same frame twice. If they didn't do that, it would almost certainly cause issues with the low persistence displays used in these headsets. They only flash the image for a short part of the frame time, and go black for the remaining portion. Running the display at 45 fps would probably cause noticeable flicker and such, especially for people sensitive to it. There is a reason these headsets have all targeted 90 fps though; simple frame doubling will probably be insufficient.

What you are talking about with HDTVs is interpolation. This is creating a new frame in between two existing frames to smooth out the motion. This is a bad idea for VR. Some HDTVs do interpolation by adding, at a minimum, an extra frame of latency. That is, they take the frame at time 'x' and the fame at time 'x + 1' and create a frame at time 'x + 0.5' to show in between them. The input must be at the 'x + 1' frame before the 'x + 0.5' frame can be shown. In reality, there may be several frames of latency introduced by the processing that the television is doing. My TV isn't even doing that much processing since it is from about 2010 or so. If I take the analog audio output directly from my cable box, it is noticeably out of sync with the audio from the television due to added latency. For VR, you want to be able to produce another frame from the current frame and maybe the previous frame ('x' and 'x - 1'), not from frame 'x' and frame 'x + 1'. You would not want to add interpolation latency to a VR headset, which is why I suggested just shifting the frame to match the users head movement. This requires almost no processing. They could add some extra processing, but it seems like that could look quite bad due to artifacts.

March 25, 2016 | 04:05 AM - Posted by djotter

I have the baby brother to your camera; the Sony Nex-5R, and love it too. Fast autofocus to catch the kids on the go, large APS-C sensor for high quality pics and small enough to fit in a jacket pocket.

Though the A7 SII is a full frame sensor, you can still record nice 4K with the smaller sensor.

March 25, 2016 | 08:41 AM - Posted by collie

I hate that I keep missing the live stream, but winter is over so I'm back to a summer cooks schedule, so collie will be scarce, but I'm still downloading the cast and lissening on my way to work, so that's sumptin.

baba booey! baba booey!

March 27, 2016 | 06:32 AM - Posted by dragos (not verified)

About the helium HDDs. I work with 100kRPM+ motors and one of the ways to reduce losses and increase thermal transfer is to fill them with helium. Helium transfers heat 8 times better than air, see below:
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

I'm curious what you think, if it mattered for the HDD designers. In electric motors it does.

March 27, 2016 | 11:07 PM - Posted by Vesperan (not verified)

I had hoped that Ryan would provide an additional 10 cents to the feedback on AMDs Capsaican event. The guys did an admirable job of covering it in last week's podcast, but I would have loved to his impressions on it.

..and apologies if he did cover it, I listen to most of my podcasts at 3am in the morning.

March 30, 2016 | 06:33 PM - Posted by Ryan Shrout

What would you like touched on?

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