Why cannot a CPU be used as a GPU?

[Sauron]

20 minutes ago, Mark Kaine said:

That's actually kinda what these "voodoo" cards were?

Not quite, old 3dfx voodoo cards were already capable of 3d acceleration and hardware rendering whereas the "gpu" made in that video is just a video output buffer which doesn't actually do anything to generate the image. It's closer to the older CGA and EDA adapters from the early '80s but with a VGA standard output.

[djneo]

So intel did try to use X86 based cpu's to make an GPU 
https://www.youtube.com/watch?v=um-1fAVU1OQ

[whm1974]

1 hour ago, Sauron said:

Not quite, old 3dfx voodoo cards were already capable of 3d acceleration and hardware rendering whereas the "gpu" made in that video is just a video output buffer which doesn't actually do anything to generate the image. It's closer to the older CGA and EDA adapters from the early '80s but with a VGA standard output.

The Voodoo 1 and 2  only did Fixed function 3D Acceleration. And you needed a 2D Graphics Card to use with it. The same with a Matrox Card at the time.

 

Wasn't until 1999 that the Voodoo 3 appeared that you need one Card. What 3Dfx had wasn't a true GPU at all.

[Helpful Tech Witch]

You can, but it’s bad.

remember the ltt video on the m.2 gpu?

that only had 2d output, so when it ran a 3d engine game, it would make the cpu render it (the the game used direct x)

[Mark Kaine]

2 hours ago, HelpfulTechWizard said:

You can, but it’s bad.

remember the ltt video on the m.2 gpu?

that only had 2d output, so when it ran a 3d engine game, it would make the cpu render it (the the game used direct x)

I still want to know how my Pentium was able to play 3d DOS games without any issues whatsoever - yes the graphics were very basic,  but not worse than say a PS1 at the time, and i coulda sworn 60fps too, at least there were no slowdowns  - i mostly played 3d stunts tbh,  but even stuff like midtown madness ran without issues...

 

I get it for modern AAA games a Pentium obviously wouldn't cut it, but at the time, "3d" wasn't an issue at all... i think there's probably more to it, like different game engines,  especially designed to run on slow CPUs, just like "1mb" was often enough for a full fledged 3d game, totally unthinkable nowadays were even low grade indie pixel games can use several GB... 

 

PS: what I really wanted was a sound card, the onboard sound always seemed ridiculously low end to me, nowadays I absolutely love it however (especially for 3d stunts... *screeeeech* *bleep*  )

 

Quote

Think thats with a soundcard maybe? But anyways this looks and sounds exactly how I remember otherwise  

 

[mariushm]

Those games ran at 320x200 ... 640x480 and had MUCH simplified graphics ... and often these games used only 256 colors or 16bit (65k colors) ...if it was a 3d game think of it as each frame having 5-10k triangles/polygons compared to hundreds of thousands of triangles/polygons per frame in modern games.

The video cards in those old computers actually had some 2D acceleration functions which were used by windows 95 through direct draw and opengl ... dos games often had separate video "drivers" for various video cards to support some features ...there was an effort and that's where VESA came and sort of standardized a minimum set of functions a video card should have, so a game would only need one video card driver... then directx came to compete with glide (voodoo) and opengl.

[Spindel]

Already said but I’ll say it again: yes you can, it will just be very much slower.

 

See the CPU as a swiss army knife or a leatherman, loads of tools available for all kinds of tasks. Rendering graphics in this analogy is like a screw that needs to be screwed in. A task that can be done with your swiss army knife or leatherman with one of the available tools, slow process but it gets the job done.

 

In the anology above the GPU is an electric screw driver, really fast and efficient at screwing in screws and maybe at drilling holes in not to hard materials but kind of useless for cuting something or if you need a pair of pliers.

[whm1974]

6 hours ago, mariushm said:

Those games ran at 320x200 ... 640x480 and had MUCH simplified graphics ... and often these games used only 256 colors or 16bit (65k colors) ...if it was a 3d game think of it as each frame having 5-10k triangles/polygons compared to hundreds of thousands of triangles/polygons per frame in modern games.

The video cards in those old computers actually had some 2D acceleration functions which were used by windows 95 through direct draw and opengl ... dos games often had separate video "drivers" for various video cards to support some features ...there was an effort and that's where VESA came and sort of standardized a minimum set of functions a video card should have, so a game would only need one video card driver... then directx came to compete with glide (voodoo) and opengl.

Didn't those DOS Games use something like some sort of Pseudo 3D or something? Duke Nukem 3D had the BUILD Engine,

[Mark Kaine]

11 hours ago, mariushm said:

The video cards

This is kinda my point - I'm not aware this PC has a "video card" ... maybe it has a very rudimentary one*, but I always had the impression the games actually run on the CPU, in which case it's not really super relevant to say modern games are much more advanced,  because so are CPUs, the question is "how" did this work back then, I mean resolution might be low, its still "3D" and 60fps (or at least a playable framerate)

I kinda also wonder IF we had continued to use DOS how much more advanced games could have gotten (with a dedicated "video card" or not)

 

*kinda hard to find the proper specs lol, its a Fujitsu Ergo Pro X (very small form factor) with a "Pentium 1" CPU... not aware of any kind of GPU (as mentioned)

 

Edit:

Spoiler

 

Edit 2: hold on... i think this might have "on board graphics"? (Which i don't see mentioned anywhere)

 

Spoiler

 

ATi chip in Intel PC, sus!

 

[whm1974]

5 hours ago, Mark Kaine said:

This is kinda my point - I'm not aware this PC has a "video card" ... maybe it has a very rudimentary one*, but I always had the impression the games actually run on the CPU, in which case it's not really super relevant to say modern games are much more advanced,  because so are CPUs, the question is "how" did this work back then, I mean resolution might be low, its still "3D" and 60fps (or at least a playable framerate)

I kinda also wonder IF we had continued to use DOS how much more advanced games could have gotten (with a dedicated "video card" or not)

 

*kinda hard to find the proper specs lol, its a Fujitsu Ergo Pro X (very small form factor) with "Pentium 1" CPU... not aware of any kind of GPU (as mentioned)

DOS was very limited. No Multitasking at all, or even any Graphics APIs.  There Glide for DOS but no game I'm aware of supported it.

[whm1974]

6 hours ago, comander said:

1. You CAN use a CPU to render graphics. Here's crysis on a 64 core threadripper 

2. CPUs are designed to do a wide range of calculations reasonably well - as such they have a small number of large cores. GPUs are designed to do a narrower range of calculations VERY quickly. They're essentially large vector calculation engines with many, many low performance cores.

Trading some flexibility for between 100-1000x the performance makes a lot of sense for some cases and is a great reason for WHY GPUs are a thing. 

 

 

LRB was one of the projects my uncle worked on when he was at Intel. 

Was that later sold by Intel as "Supercomputer" on a PCIe Card? As I recall they didn't sell all that many, and there were not any Applications for it. Buyers had write specialize code to even use at all.

 

The only major users I heard about put them in a "Cluster in Box".

[Mark Kaine]

On 10/5/2021 at 10:53 PM, whm1974 said:

DOS was very limited. No Multitasking at all, or even any Graphics APIs.  There Glide for DOS but no game I'm aware of supported it.

Turns out this pc has an "igpu" (Ati mach 64?) but not on the cpu but on the motherboard. I didn't know that was a thing back then, but thats also why I asked how it worked, because playing 3d games at 60fps on a first gen Pentium seemed always kinda sus tbh ; ) 

 

Yeah it probably was limited,  but what it did it did very well...  

[mariushm]

Yeah...  

Back then, there was either integrated graphics in the chipset - SiS had a lot of cheap chipsets with integrated graphics, Via had a few, ALI and others had some... or they added graphic chips on the motherboard from companies like ATI, Matrox, Cirrus Logic, S3, Tseng Labs...

 

They were typically connected to the chipset (well, either northbridge or southbridge, because back then we actually had a chip SET so saying chipset made sense) through PCI bus.

 

Later we had northbridge chips that had a separate dedicated connection for video cards, so that you don't have to transfer data to and from the card through the PCI bus which was limited at 133 MB/s on regular PCs, and that's how AGP popped up (accelerated graphics port)

 

There was some 3d/2d accelerator cards with some special functions, but there was no universal driver, the games had to have explicit support for that video card.. similarly to how you had to go in game setup and select sound card, irq , dma channel, ports etc etc

Then vesa got their act together and standized some resolutions and refresh rates, so you could say in setup my card can do 800x600 vesa and you knew it would work. 

 

[Guest]

On 10/2/2021 at 1:49 PM, archerbob said:

How could one custom build a GPU?

 

 

Intel CPUs already have a GPU in them (Unless it has an F at the end iirc)

 

most AMD ones don't though, so F for them ig

[WolframaticAlpha]

On 10/3/2021 at 12:16 AM, Lurick said:

You need a small loan of about $20 billion to start

15 bil is my final offer. Take it or leave it 

[whm1974]

2 hours ago, mariushm said:

Yeah...  

Back then, there was either integrated graphics in the chipset - SiS had a lot of cheap chipsets with integrated graphics, Via had a few, ALI and others had some... or they added graphic chips on the motherboard from companies like ATI, Matrox, Cirrus Logic, S3, Tseng Labs...

 

They were typically connected to the chipset (well, either northbridge or southbridge, because back then we actually had a chip SET so saying chipset made sense) through PCI bus.

 

Later we had northbridge chips that had a separate dedicated connection for video cards, so that you don't have to transfer data to and from the card through the PCI bus which was limited at 133 MB/s on regular PCs, and that's how AGP popped up (accelerated graphics port)

 

There was some 3d/2d accelerator cards with some special functions, but there was no universal driver, the games had to have explicit support for that video card.. similarly to how you had to go in game setup and select sound card, irq , dma channel, ports etc etc

Then vesa got their act together and standized some resolutions and refresh rates, so you could say in setup my card can do 800x600 vesa and you knew it would work. 

 

I'll look this up, but AFAIK Matrox didn't Graphics Chips on the Motherboard itself. But only made Graphics Cards using their own Dies they design themselves. And they didn't sell those to other Card makers.

 

Once DirectX gotten way better with 95 OSR and later 98, and OpenGL with games, Games for DOS slowly disappeared.

 

VESA already Standardize SuperVGA before DOS was finely replace by Windows 9x and NT. But it was up to the Video Card Manufacture to provide VESA support.