5 ms·

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

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 other things that "help them win the framerate wars", but a developer should be able to turn all of that off when needed. It's the same with displays. LCD manufacturers could, I suppose, allow a modern day "CRT Mode 13h" where you just have scan lines mapped to memory buffers and whatever shows up in those buffers gets turned into a pixel as quickly as possible. Are there technical challenges preventing this from happening, or is it mainly inertia and lack of need from the current market?

niggler 14y ago
"a set of standard low-level control primitives ... Are there technical challenges preventing this from happening, or is it mainly inertia and lack of need from the current market?" It's easier to iterate faster without having to deal with a standardization committee. See OpenGL history for some context.
Scene_Cast2 14y ago
Regarding your last point: it's getting better. Modern TVs have "game mode", where latency is minimized. The latest LCD panels use embedded Display Port, eDP. The latest eDP standard introduces a frame buffer on the LCD itself, where you can just write deltas and tell it to "swap". I think this is quite similar to what you're proposing, in concept.
- breckinloggins 14y ago
  I found this [1], which seems to be a good introduction to the new features and also why eDP is poised to replace LVDS (which I, as a non hardware guy, had to deal with in a previous embedded device project and hope to never deal with again). [1] http://embedded-computing.com/articles/embedded-greater-display-efficiency/ http://embedded-computing.com/articles/embedded-greater-disp...
- bbatchelder 14y ago
  You may already know this, but the "Game Mode" on modern TVs is just turning off the 120Hz/240Hz interpolation that is done to "improve" the picture (or is required for certain 3D systems to work). The interpolation introduces significant latency that its obvious (and frustrating) during gaming. I actually run my TV in game mode by default, because the interpolation done in 120/240Hz mode makes everything look like it is slightly unreal and shot on video. Definitely uncanny valley territory.
  - newman314 14y ago
    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.
    - gizmo686 14y ago
      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.
      - Tuna-Fish 14y ago
        Having the frame change every second frame would mean that the screen would be changing the picture only half the time, while it normally is always changing the color of some pixel. Not sure that this is not just a pure win.
      - mmcnickle 14y ago
        It affects the amount of motion blur that has to be applied to give a feeling of fluid movement, especially action scenes.
    - fla 14y ago
      Very glad I'm not the only one to notice it.
seanalltogether 14y ago
Carmack has also mentioned in the past we could solve other buffer problem with non-isochronous displays, essentially a display that doesn't run on a fixed hz cycle but rather outputs lines to the screen as it comes down the pipeline at whatever framerate the host system can handle
- trafficlight 14y ago
  Do such displays exist?
rmc 14y ago
One problem is that lots of people think they know what they are doing, but actually don't. You also have the problem of people choosing to use "expert mode" because it's faster, obviously.
- breckinloggins 14y ago
  That's why I think the default should always be "babysitter mode". Unless you give a specific set of commands, the GPU does what it does and the display does its thing. Regarding people who turn on "expert mode" even when they don't know what they're doing, that doesn't seem to be a good reason for not having it. The Mark Twain quote about censorship being like "telling a grown man he can't have a steak because a baby can't chew it" comes to mind.
  - bradleyjg 14y ago
    Let's say a hardware manufacturer writes a firmware that exposes calls that can degrade or destroy the device if misused, and the OS driver in turn exposes those calls to third party programs. If a program wreaks the device, who is the end user going to blame -- the program, the driver, the manufacturer, or all three?
    - derefr 14y ago
      Maybe the hardware manufacturer can certify and sign game binaries as being allowed to use the direct GPU API.
      - jzwinck 14y ago
        Didn't Secure Boot already show us what reaction people will have to mandatory signing?
        derefr 14y ago
        Without the signature, the app would just go slower.
binarycrusader 14y ago
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.
- coldtea 14y ago
  >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?
  - GauntletWizard 14y ago
    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?
  - binarycrusader 14y ago
    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").
ZoFreX 14y ago
Believe it or not but we have a similar problem with CDROM drives (let alone any drives coming after). You can't disable the cache on most, and on many that claim to, they lie. This slows down accurate ripping by a factor of 40X on some drives. On the topic of latency I would also love to see a TV that didn't have any of the crummy video processing chips so many have these days. I don't need anything other than big screen, hdmi in, and no freakin' input latency please because I'm trying to play Rock Band and you are really messing things up! (You can admittedly at least disable this in some tvs... often by delving into hidden engineering menus. Sometimes you can't disable them at all!)
- nuclear_eclipse 14y ago
  > On the topic of latency I would also love to see a TV that didn't have any of the crummy video processing chips so many have these days. Many modern TV's have a special "game mode" setting that turns off all of this post-processing to reduce display latency. I use it with great success on my Panasonic plasma TV.
greggman 14y ago
I don't think that's needed. What's needed is just to let competition work. If one GPU is less laggy in VR than another people will by that GPU for VR. No need to work around the driver, demand will make the drivers better.
MichaelGG 14y ago
Yea that works, until someone realises they can boost performance by changing the semantics of the "I know what I'm doing" call. Then you'll need yet another "no really I know what I'm doing" flag and on and on, or app black/whitelisting and so on.
- rmc 14y ago
  Just add an "expert mode" that does nothing. Placebo, it works.

niggler 14y ago

"a set of standard low-level control primitives ... Are there technical challenges preventing this from happening, or is it mainly inertia and lack of need from the current market?" It's easier to iterate faster without having to deal with a standardization committee. See OpenGL history for some context.

Scene_Cast2 14y ago

Regarding your last point: it's getting better. Modern TVs have "game mode", where latency is minimized. The latest LCD panels use embedded Display Port, eDP. The latest eDP standard introduces a frame buffer on the LCD itself, where you can just write deltas and tell it to "swap". I think this is quite similar to what you're proposing, in concept.

breckinloggins 14y ago
I found this [1], which seems to be a good introduction to the new features and also why eDP is poised to replace LVDS (which I, as a non hardware guy, had to deal with in a previous embedded device project and hope to never deal with again). [1] http://embedded-computing.com/articles/embedded-greater-display-efficiency/ http://embedded-computing.com/articles/embedded-greater-disp...
bbatchelder 14y ago
You may already know this, but the "Game Mode" on modern TVs is just turning off the 120Hz/240Hz interpolation that is done to "improve" the picture (or is required for certain 3D systems to work). The interpolation introduces significant latency that its obvious (and frustrating) during gaming. I actually run my TV in game mode by default, because the interpolation done in 120/240Hz mode makes everything look like it is slightly unreal and shot on video. Definitely uncanny valley territory.
- newman314 14y ago
  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.
  - gizmo686 14y ago
    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.
    - Tuna-Fish 14y ago
      Having the frame change every second frame would mean that the screen would be changing the picture only half the time, while it normally is always changing the color of some pixel. Not sure that this is not just a pure win.
    - mmcnickle 14y ago
      It affects the amount of motion blur that has to be applied to give a feeling of fluid movement, especially action scenes.
  - fla 14y ago
    Very glad I'm not the only one to notice it.

seanalltogether 14y ago

Carmack has also mentioned in the past we could solve other buffer problem with non-isochronous displays, essentially a display that doesn't run on a fixed hz cycle but rather outputs lines to the screen as it comes down the pipeline at whatever framerate the host system can handle

trafficlight 14y ago
Do such displays exist?

rmc 14y ago

One problem is that lots of people think they know what they are doing, but actually don't. You also have the problem of people choosing to use "expert mode" because it's faster, obviously.

breckinloggins 14y ago
That's why I think the default should always be "babysitter mode". Unless you give a specific set of commands, the GPU does what it does and the display does its thing. Regarding people who turn on "expert mode" even when they don't know what they're doing, that doesn't seem to be a good reason for not having it. The Mark Twain quote about censorship being like "telling a grown man he can't have a steak because a baby can't chew it" comes to mind.
- bradleyjg 14y ago
  Let's say a hardware manufacturer writes a firmware that exposes calls that can degrade or destroy the device if misused, and the OS driver in turn exposes those calls to third party programs. If a program wreaks the device, who is the end user going to blame -- the program, the driver, the manufacturer, or all three?
  - derefr 14y ago
    Maybe the hardware manufacturer can certify and sign game binaries as being allowed to use the direct GPU API.
    - jzwinck 14y ago
      Didn't Secure Boot already show us what reaction people will have to mandatory signing?
      - derefr 14y ago
        Without the signature, the app would just go slower.

binarycrusader 14y ago

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.

coldtea 14y ago
>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?
- GauntletWizard 14y ago
  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?
- binarycrusader 14y ago
  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").

ZoFreX 14y ago

Believe it or not but we have a similar problem with CDROM drives (let alone any drives coming after). You can't disable the cache on most, and on many that claim to, they lie. This slows down accurate ripping by a factor of 40X on some drives. On the topic of latency I would also love to see a TV that didn't have any of the crummy video processing chips so many have these days. I don't need anything other than big screen, hdmi in, and no freakin' input latency please because I'm trying to play Rock Band and you are really messing things up! (You can admittedly at least disable this in some tvs... often by delving into hidden engineering menus. Sometimes you can't disable them at all!)

nuclear_eclipse 14y ago
> On the topic of latency I would also love to see a TV that didn't have any of the crummy video processing chips so many have these days. Many modern TV's have a special "game mode" setting that turns off all of this post-processing to reduce display latency. I use it with great success on my Panasonic plasma TV.

greggman 14y ago

I don't think that's needed. What's needed is just to let competition work. If one GPU is less laggy in VR than another people will by that GPU for VR. No need to work around the driver, demand will make the drivers better.

MichaelGG 14y ago

Yea that works, until someone realises they can boost performance by changing the semantics of the "I know what I'm doing" call. Then you'll need yet another "no really I know what I'm doing" flag and on and on, or app black/whitelisting and so on.

rmc 14y ago
Just add an "expert mode" that does nothing. Placebo, it works.