John Carmack Interview • Hacker News Board

Re: John Carmack Interview

#21

Post by qrybam » Thu, Apr 14, 2011, 10:21 AM UTC

chipsy wrote: post #9

kenjackson wrote: post #4

Earlier quoted context omitted.

Do you think 60Hz is the right rate? Just seems like such a huge jump over 30. Does 48 make more sense?

In competitive play it makes a big difference. Each frame of a 60Hz game spans 16.66ms, while in a 30Hz game it's 33.33ms. Depending on how well the engine is coded, there will be at least one frame of latency between input and reactions, and maybe more. So we could be looking at the difference between 33 and 66 milliseconds of input latency, at least. This doesn't even consider latency from input to the computer, or…

Agreed on it making a difference in competitive play. Though 200-300ms is a pretty slow response time (especially in a competitive environment - depends on the game I suppose). In most twitchy games (actually in most games) people's reactions would be in the 20-100ms range.

One of the interesting things that can happen if you v-sync a game that's capped to 60FPS on a screen which has a refresh rate that is not a multiple of 60 (e.g. 70 or 100, etc) is the addition of mouse lag to the game (there's an added delay between moving the mouse and actually seeing the action happen on the screen).

Re: John Carmack Interview

#22

Post by seanalltogether » Thu, Apr 14, 2011, 8:29 PM UTC

qrybam wrote: post #19

joeld42 wrote: post #5

Earlier quoted context omitted.

You can't control the actual refresh rate of the monitor or TV. The display refreshes at 60hz, you can draw every frame, or every other frame and have twice the time. And yet, like he says, Rage looks better than most 30hz games.

Depends on the monitor. You're pretty much stuck when it comes to most current TVs and LCD/LED displays as well (60Hz, 70Hz, 75Hz sometimes 100Hz). Before flat screens were affordable we were all using CRTs. A good CRT could push a 150Hz refresh rate. When Quake3 was still being played competitively (it /kind/ of still is with QuakeLive, but it's not the same anymore imo) we ran the game at a capped 120 FPS, set the…

Thank you for pointing this out. People sometimes think I'm crazy when i talk about pushing really high fps. The human eye can detect objects that exist for 1/200th of a second, so pushing higher framerates will always make things smoother. I'm really surprised that all lcd monitors aren't running at 120hz or 240hz, obviously they can't be that hard to make if the tv manufactures are pushing them out.

Re: John Carmack Interview

#23

Post by harto » Thu, Apr 14, 2011, 11:55 PM UTC

kenjackson wrote: post #4

seanalltogether wrote: post #3

I'm always happy to hear when developers optimize for refresh rate over graphical complexity, especially if competitive play will be involved.

Do you think 60Hz is the right rate? Just seems like such a huge jump over 30. Does 48 make more sense?

Out of interest, why 48 specifically?

Re: John Carmack Interview

#24

Post by qrybam » Fri, Apr 15, 2011, 11:33 AM UTC

seanalltogether wrote: post #22

qrybam wrote: post #19

Earlier quoted context omitted.

Depends on the monitor. You're pretty much stuck when it comes to most current TVs and LCD/LED displays as well (60Hz, 70Hz, 75Hz sometimes 100Hz). Before flat screens were affordable we were all using CRTs. A good CRT could push a 150Hz refresh rate. When Quake3 was still being played competitively (it /kind/ of still is with QuakeLive, but it's not the same anymore imo) we ran the game at a capped 120 FPS, set the…

Thank you for pointing this out. People sometimes think I'm crazy when i talk about pushing really high fps. The human eye can detect objects that exist for 1/200th of a second, so pushing higher framerates will always make things smoother. I'm really surprised that all lcd monitors aren't running at 120hz or 240hz, obviously they can't be that hard to make if the tv manufactures are pushing them out.

You're right, I've argued with a few of my friends over this in the past. Also, something I should have mentioned before (and I should correct myself), the refresh rate on a LCD screen isn't quite the same thing as that on the CRT. So, even though a 120Hz LCD would refresh the image 120 times a second, for some reason it just doesn't feel as nice and fluid as on the CRT.

That v-sync mouse lag I mentioned has only ever happened to me when I'm using an LCD rather than CRT - which is the main reason why I wouldn't use v-sync when playing an FPS.