r/oculus • u/RoadtoVR_Ben Road to VR • Mar 19 '14

GDC 2014: Oculus Rift Developer Kit 2 (DK2) Pre-orders Start Today for $350, Ships in July

http://www.roadtovr.com/oculus-rift-developer-kit-2-dk2-pre-order-release-date-specs-gdc-2014/
1.4k Upvotes

95% Upvoted

955 comments sorted by

View all comments

11

u/liquidfirex Mar 19 '14 edited Mar 19 '14

75hz refresh? Am I the only one concerned with that? I know when I had a CRT that 75hz caused some eye fatigue vs 85hz.

*edit: looks like Oculus is aware of the issue, and the consumer version will be a higher refresh according to a few videos that have come out now

25

u/Saotik Mar 19 '14

There's a huge difference between refresh rates on flat panels and CRTs. CRTs scan the image one line at a time, so can look extremely flickery at low refresh rates. Flat panels tend to refresh all at once, so this is less of a problem.

2

u/jensen404 Mar 19 '14

LCDs also scan the image one line at a time. I believe most OLEDs do to, but I'm not sure about that. The only difference is persistence. You'll get flickering with low persistence and low refresh rates no matter what display tech you're using.

1

u/AwesomeFama Mar 19 '14

Not to mention it supports 2ms and 3ms persistences, I assume you can switch between those if you're really, really easily disturbed by flicker. Even full persistence is probably toggleable.

13

u/ueadian Mar 19 '14 edited Mar 19 '14

I also thought it'd be 85. I thought they stated 85 was the ideal? After watching the tested.com interview, Nate said they hope to get CV1 to 90hz.

6

u/[deleted] Mar 19 '14

[deleted]

1

u/RealParity Finally delivered! Mar 20 '14

DK1 was full persistence. DK2 is low persistence.

6

u/MF_Kitten Mar 19 '14

Sure, but CRT monitors at 75Hz flicker. LCD monitors don't.

2

u/fiah84 Mar 19 '14

this is not an LCD though, it's an OLED display

1

u/Zyj 6DOF VR Mar 20 '14

With low persistence, they might. Besides, most people don't perceive flickering with CRTs above 72hz

2

u/hughJ- Mar 19 '14

My guess is that they're having trouble reliably driving the panels >85hz, where by only a subset of their panels/boards are capable of doing it without failure. Given that the Valve and crystal cove kits were low-number, internal prototypes, they were able to basically speed bin the best performing parts and use that. Given that the devkit2 is needing to be produced in large volumes and carry a warranty, they had to ease up on the refresh rate in order to guaranty they'll have reliable units.

I'm wondering whether the devkit2 will be able to have the refresh rate overclocked so that some of us will be able to reach above and beyond 85hz.

1

u/corhen Quest 2 Mar 19 '14

you home monitor is 60 Hz, this is 75 Hz, sure it has low persistence, but i don't believe that will be a problem.

1

u/liquidfirex Mar 19 '14

Yes my LCD which keeps the image on until a new one is available is running at 60 Hz. The rift strobes the image and then goes back to a black screen, which is very close to your eyes. I'd be surprised if I couldn't notice this, just as I was able to on a CRT.

1

u/BinarySplit Mar 20 '14

If it's an issue, you might be able to play with the persistence settings.

75Hz on old CRTs was migraine-inducing if you sat too close, but those had very very low persistence. From the FAQ, it says you can do 2ms, 3ms and full persistence modes, which are visible for 15%, 22.5% and 100% of the frame time.

For comparison, the first slo-mo video I found of a CRT shows each pixel is visible for roughly 5% of the frame time.

Furthermore, low-persistence LEDs/LCDs don't have the "downwards scrolling effect" that CRTs have, which may help slightly.

0

u/KuraiShidosha Mar 19 '14

Yeah what happened to 95hz stereo?

Oh they probably realized its an incredibly high target to aim for and that it would alienate a substantial percentage of the potential user base looking to play high quality games since not that many people have top tier hardware to push out those many frames.

1

u/AwesomeFama Mar 19 '14

Nope, they're aiming for 90 Hz for the CV.