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John Carmack: Latency Mitigation Strategies

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Re: John Carmack: Latency Mitigation Strategies

#91

Post by Tuna-Fish »

nitrogen wrote: post #20
mtgx wrote: post #13

Earlier quoted context omitted.

Well Oculus Rift should support everything from PC's to consoles. But I agree. Stuff like Oculus Rift is the true next-gen computing. The PS4 and next Xbox leave me pretty cold, especially when I already have a laptop that can already play all the latest games.

I think the PS4's insane memory bandwidth (8GB of memory on a 170GB/sec GDDR5 bus) makes it a very interesting contender against PCs (dual-channel DDR3 maxes out at 34GB/s).

The memory bandwith is perfectly normal for GPUs, though. And the CPU will mostly suffer from the GDDR5, because it has much higher latencies.

Re: John Carmack: Latency Mitigation Strategies

#92

Post by Tuna-Fish »

roc wrote: post #64
nitrogen wrote: post #50

Earlier quoted context omitted.

They may be using an off-the-shelf x86 core , but their actual CPU die may have all kinds of customizations on it (like the addition of a GDDR5 memory controller). AIUI GDDR5 memory is much more expensive than DDR3. So it may happen eventually, but I don't think it will be any time soon, and believe me, I really want PCs to be better than consoles in every way.

It just seems to me that whatever they're doing with AMD, AMD is going to be able to farm out to other parties. Given that both MS and Sony are using AMD cores paired with GDDR5 memory controllers, it seems almost certain that there's nothing approaching an exclusivity contract to prevent AMD from now selling that bundle to any maker of gaming PCs or SteamBox builds or whatever else. And the current/historical cost d…

> Given that both MS and Sony are using AMD cores paired with GDDR5 memory controllers

They are not. MS is using DDR3 at 256 bits * 2100MHz for 68GB/s bandwidth.

Re: John Carmack: Latency Mitigation Strategies

#93

Post by coldtea »

binarycrusader wrote: post #74
breckinloggins wrote: post #31

It sounds like we would benefit from GPU and display manufacturers providing a set of standard low-level control primitives so that people like Carmack who know what they are doing can really play around with the entire pipeline without having to worry about all the things the cards and the displays are doing behind their backs. For example, a GPU could have a set of standard settings with full buffering and all the…

3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. That's why Carmack is able to get modified versions of these drivers directly, but you and I are not. I don't agree with that approach at all, but it's part of the reality.

>3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out.

Why the duck would video card manufactures care if people cheat in video games?

Heck, why would even GAME manufactures care if people cheat in video games?

Can somebody clear up if that is the real reason those debug options etc were taken out?

Re: John Carmack: Latency Mitigation Strategies

#94

Post by GauntletWizard »

coldtea wrote: post #93
binarycrusader wrote: post #74

Earlier quoted context omitted.

3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. That's why Carmack is able to get modified versions of these drivers directly, but you and I are not. I don't agree with that approach at all, but it's part of the reality.

> 3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. Why the duck would video card manufactures care if people cheat in video games? Heck, why would even GAME manufactures care if people cheat in video games? Can somebody clear up if that is the real reason those deb…

Game manufacturers care because their customers care, and because the same cheats often are related to copy-protection breaking. If you're going to cheat at videogames, why not do so in games you didn't buy?

Re: John Carmack: Latency Mitigation Strategies

#95

Post by binarycrusader »

coldtea wrote: post #93
binarycrusader wrote: post #74

Earlier quoted context omitted.

3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. That's why Carmack is able to get modified versions of these drivers directly, but you and I are not. I don't agree with that approach at all, but it's part of the reality.

> 3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. Why the duck would video card manufactures care if people cheat in video games? Heck, why would even GAME manufactures care if people cheat in video games? Can somebody clear up if that is the real reason those deb…

I never meant to imply it was the only reason, just that it was one of them. Another is the support considerations; each option you add to the drivers to tweak rendering output is yet another permutation of testing.

In addition, some of the options better fit the old fixed pipeline architecture of the early 2000s; forcing some of the rendering options older drivers used to have isn't really possible in a fully programmable world.

But to expound a bit on the cheating angle, one manufacturer (Asus) even went so far as to specifically market these features as a competitive advantage for customers of their products:

  http://www.theregister.co.uk/2001/05/10/asus_releases_games_cheat_drivers/
With that said, users that installed the debug versions of the windows DirectX framework (historically) and the various developer tools (such as nVidia insight) have some of the same capabilities that used to be built-in to older drivers.

Developers have combated this by using programs like punkbuster or rolling their own tools (Blizzard wrote "Warden").

Re: John Carmack: Latency Mitigation Strategies

#96

Post by mmcnickle »

gizmo686 wrote: post #86
newman314 wrote: post #81

Earlier quoted context omitted.

This. Some people aren't able to tell this apparently but it absolutely bothers the heck out of me. Probably the reason why I'm not a fan of 48fps either. I still think it would be useful to have a variable rate player. 24fps for normal scenes and 48fps for action.

Is there a detectable (to human) difference between a 24fps screen and a 48fps screen where the image only changes every other frame. I can see how this would work with film based projectors, but my understanding of TVs is that pixels are always on and simply change states between frames, so 'changing' to an identical frame should have no effect.

It affects the amount of motion blur that has to be applied to give a feeling of fluid movement, especially action scenes.

Re: John Carmack: Latency Mitigation Strategies

#98

Post by TruthElixirX »

neverm0re wrote: post #30
modeless wrote: post #19

Earlier quoted context omitted.

Eye tracking would be awesome but it's not required for good VR. I fail to see how "using your head as a dumb camera joystick" is a problem; that's the whole point of VR. Motion sickness is a real problem for some people (but not all). With low latency and thoughtful game design I think it can be mitigated. The bigger problem is the social acceptability of blocking your entire field of vision for long periods of time…

> I fail to see how "using your head as a dumb camera joystick" is a problem; that's the whole point of VR. Perhaps you should try playing some VR games for a while. I clocked quite a few hours playing the old Virtuality SU2000 games like Dactyl Nightmare and I've idly kept up with HMDs. The chief problem is that without eye tracking, it's incredibly UNFUN to use your head for movements that your eyes could otherwise…

>This lead to policy that the 3D effect could not be used for anything related to actual gameplay mechanics, reducing it entirely to an optional gimmick.

Citation? I had not heard this about the 3DS.

Re: John Carmack: Latency Mitigation Strategies

#99

Post by dspillett »

coldtea wrote: post #93
binarycrusader wrote: post #74

Earlier quoted context omitted.

3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. That's why Carmack is able to get modified versions of these drivers directly, but you and I are not. I don't agree with that approach at all, but it's part of the reality.

> 3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. Why the duck would video card manufactures care if people cheat in video games? Heck, why would even GAME manufactures care if people cheat in video games? Can somebody clear up if that is the real reason those deb…

> Why the duck would video card manufactures care if people cheat in video games?

They care because game makers care. If they want their logo in the pre-game splashes and similar they need to not be a problem to the people who decide what goes there or it'll end up costing more than it would cost the compatetion. Also they certainly don't want someone like EA coming out and explicitly saying they don't recommend their line of graphics systems.

> Heck, why would even GAME manufactures care if people cheat in video games?

Way back when, they didn't. Well they did, but only for the first X weeks after which any sectret and big ending reveals were public knowledge anyway afte3r which they'd leak out cheat codes themselves to increase interest inthe game from more casual players.

Now they care because their customer base cares. The perception that someone might get an advantage by using a particular card will put a lot of people off. Even if it isn't really possible (because the game is well enough designed that such hacks won't really give any advantage) the perseption amongst the general public that it might be is enough to be concerned about.

> Can somebody clear up if that is the real reason those debug options etc were taken out?

Not unlikely: they were probably pig sick of people breaking things and blaming them for the resulting mess (I tweaked X and your card overheated and my computer crashed and I lost three days of unsaved work, waah, waah, waaaaaahhh).

Or people tweaking the settings, making things far worse in some circumstances, and then assuming that the card is crap (and telling everyone) because to does X badly without thinking that their tweaks might have a little to do with that.

Or they were sick of getting many support queries about the options, or having to make an effort to monitor populat forums for people distributing blatently bad advice about them so they can nip the above problems in the bud. Time is money and reputation management can be expensive especially if you are having to do it retroactively.

Or all of the above. Basically people. People are a problem.

Re: John Carmack: Latency Mitigation Strategies

#100

Post by skore »

coldtea wrote: post #93
binarycrusader wrote: post #74

Earlier quoted context omitted.

3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. That's why Carmack is able to get modified versions of these drivers directly, but you and I are not. I don't agree with that approach at all, but it's part of the reality.

> 3D graphics drivers used to have more debug options and visualization capabilities. However, unscrupulous individuals took advantage of these to cheat in video games so many vendors just ripped them out. Why the duck would video card manufactures care if people cheat in video games? Heck, why would even GAME manufactures care if people cheat in video games? Can somebody clear up if that is the real reason those deb…

> Heck, why would even GAME manufactures care if people cheat in video games?

Singleplayer, maybe. But Multiplayer? Very annoying for everybody involved. Having a multiplayer opponent cheat is like having a singleplayer bug that means you cannot advance in the game.

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