"Street Fighter III" for Jag

[STGuy1040]

Lets just use the Fight For Life engine for SF4 and the Double Dragon V engine for SF3, thats all...while we are it, i dont see why we couldn get GTA4 working in the Jag with the Club Dive engine, right?

 

[STGuy1040]

If you get the system getting working really well as a whole, wouldn't it have been able to do more, using one of the RISC's handel the 3D calculations.

 

Here's a simplified description of why the Jaguar is limited in 3D. It has a lot more to do with system issues that are not very obvious from a straight spec comparison.

 

Let's compare the Playstation to the Jaguar in 3D. Wait, let me put on my flame suit first...

 

On the Jag, to do a 3D engine like you describe, you would use one RISC (let's pick the DSP) to do all the 3D math. The other RISC (the GPU) has to babysit the blitter full time. This is because the blitter can't draw polygons, only spans, and requires full RISC attention to do that task at top speed.

 

On the PS, the 3D math is performed by the GTE and complete polygons are drawn by the GPU. Both of these systems function without RISC intervention (using DMA lists).

 

The GTE is about 3 times faster than the DSP at 3D math, and it has a 133MB/second bus interface, while the DSP has 8.8MB/second. Let's say your 3D math only needs 4MB/second (to read models and emit polygon lists).

 

So for 3D math, on the Playstation, you used 3% of the main bus bandwidth, on the Jaguar, you used 50%.

 

Let's look at texture mapping. On the Jaguar, the blitter has a peak texture mapping speed of 2.4M pixels/second in main RAM, or 3.8M/second using GPU SRAM. These peaks requires 100% of the main bus. But you already used 50% for 3D, remember? So that gives the Jaguar between 1.2M-1.9M/pixels second.

 

The PS has a peak texture mapping speed of 33M pixels/second. This uses exactly 0% of the main bus, since the PS has a dedicated video graphics bus.

 

So you can already see that for texture mapped graphics, the Jaguar is at a severe disadvantage. But we don't have a game yet...

 

Game logic in most 3D titles is complicated. Collision detection in particular is very CPU and bandwidth hungry. So far we've used 0% of the PS's RISC and 3% of the main bus bandwidth. On the Jag we've used 100% of both Jag RISCs and 100% of the main bus.

 

On the Jag, we can't use the 68K because it cannot run in parallel with the RISCs. We probably can't use the DSP for game logic either, because the DSP uses too much main bus capacity and we need all of that for graphics. We could try the GPU, but the blitter can't run when the GPU is doing something else, so there is no way to run graphics in parallel with the game logic.

 

So while game logic is 'free' on the Playstation, on the Jag we are cutting deeper into precious graphics time. Even if we optimize our game logic to need only 30% of one RISC, that's the difference between 12FPS and 7.5FPS.

 

And don't forget sound. The Playstation has a dedicated sound chip with a dedicated bus, so sound playback uses no main bus bandwidth and no CPU. On the Jaguar, you need both. A good multi-channel digital audio system will shave another 15% off the Jag's capacity.

 

Not to mention video! You have to output your frame buffer at 60FPS. Assuming 320x240 in 16-bit color (used by most Jag and Playstation games), you need another 5% of the Jaguar's main bus. The PS has yet another dedicated bus for this function, so it does not consumes graphics bus, sound bus, OR main bus time.

 

So the difference between a graphics demo and a game is ~30%+15%+5% or 50% on the Jaguar! All these costs are hidden with dedicated subsystems in the Playstation.

 

It's rumored that AvP ran smoothly as a graphics demo on the Jaguar, but as they added game logic and sound, it slowed down considerably. The Playstation does not take that kind of hit.

 

My intent is not to put the Jaguar in a bad light. It was designed and released 18 months before the Playstation, which is a full technology generation by Moore's law. Also, Sony absorbed a huge loss on each Playstation sold, while the Jaguar was sold at a profit.

 

If you consider all the technical limitations of the Jag, the 3D games we have are marvels of software engineering. There is probably not a lot of performance left untapped. Of course you're welcome to try. The dev tools are free!

 

- KS

 

This is the best explanation ever given about the Jaguar's capabilities; I salute you!

[Zap!]

Also the Jaguar has twice the procesing power of a 3DO and 32X and

4 to 6 of the CD32.

 

And on paper the NY Yankees have the best team, and failed to make the playoffs last year. The best of the 3DO looks vastly superior to the best of the Jag from what I've seen.

[Gorf]

Also the Jaguar has twice the procesing power of a 3DO and 32X and

4 to 6 of the CD32.

 

And on paper the NY Yankees have the best team, and failed to make the playoffs last year. The best of the 3DO looks vastly superior to the best of the Jag from what I've seen.

 

Doom

[Gorf]

Here's a simplified description of why the Jaguar is limited in 3D.

It has a lot more to do with system issues that are not very obvious from a straight spec comparison.

 

And a lot of really bad decisions on the part of the Tramiels butting in too much in the engineering room.

The fact is it is a couple years behind the PS1. Sony clearly learned from the Jag's mistakes.

 

Jag is a bad design with chips that had no business being the release version either. The 68k was dumb.

The 020 would have made a major difference just becasue its cahce would have helped relieve the strain

on the busand it would have 32 bit data access and so would the DSP(as it is design to follow the host width.)

 

I would simply fix a few bugs on TOM....the write backs would be true multi port ram and not the skimpy fake dual

port ram that causes all the wait states. Then a double buffered blitter register and fractionals on both channels

of the blitter and the clipping fixed.

 

Give me a multi bus like the PS1 with Tom and Jerry and I think is would not only keep up with but surpass in many

aspect what the PS1 can do. I dont even need the ability to render triangles. The blitter as it is would be fine double

buffered. trips would be less work but the flexibility of raster by raster intervention can make for some unique

gfx. Even though the PS1 is a moster poly pusher over the JAguar, the Jaguar is a better machine at more classic

primites such as pixel and line manipulation. sure you can do these on the PS1 but look at Tempest on both.

The pixel blasts are not even present on PS1 nor are some of the freaky blitter trick Minter is pulling off.

 

Most of the issues in the Jaguar are simply due to the fact that because of the unified bus, all processors did more

waiting than processing. Decent tools were the biggest issues as properly written software would allow games like

Hoverstrike to be fully textured and run at 30-60 FPS. That game used a ton of 68k. move that code to the GPU

out in main and you double the performance at least. You now run at 32 bits and at RISC speed. If you run

the 68k it also slows the GPU. If the GPU is the only thing on the bus, except for page boundaries and refresh

it can run at full bus speed. You can even turn of the refresh while doing something if you are careful.

 

Jaguar II blitter is a monster and would have have no problem beating up on the PS1.

The added RGPU allowing C code with all risc able to run in main with no need for an SMAC

assembler and the compresion engine would have been rather smoking....oh if only....

 

It could have even held its own along side the N64 even at less than half the clock.

 

The N64 might have been even more of a monster if they did a few things different.

The guys that did Rouge Squadron took it to the next step and told Nintendo to go

scratch and actually went and wrote new microcode. Supposedly Nintendo had a

mich more robut engine but did not let any one use it at first...or ever.

 

 

Now I do not know much about Street fighter VI but just from the vids I would

say no, not without looking much more like FFL.

 

But there is no reason whatsoever SFIII cant be done and in fact it would do it rather well.

2D is nothing for the Jag. RAM is the only issue I'd find myself concerned with.

[Bill Loguidice]

If you get the system getting working really well as a whole, wouldn't it have been able to do more, using one of the RISC's handel the 3D calculations.

 

Here's a simplified description of why the Jaguar is limited in 3D. It has a lot more to do with system issues that are not very obvious from a straight spec comparison.

 

*snip*

 

- KS

 

This is the best explanation ever given about the Jaguar's capabilities; I salute you!

 

Agreed. Thanks so much for that!

[mcjakeqcool]

It must be noted that Street Fighter 3 is a very large game even by today's standards, at the likes of the PS1 and N64 would stuggle to have a anywere near arcade perfect port of the game, let alone the Jaguar.

[Atari_Owl]

If you get the system getting working really well as a whole, wouldn't it have been able to do more, using one of the RISC's handel the 3D calculations.

 

Here's a simplified description of why the Jaguar is limited in 3D. It has a lot more to do with system issues that are not very obvious from a straight spec comparison.

 

Let's compare the Playstation to the Jaguar in 3D. Wait, let me put on my flame suit first...

 

On the Jag, to do a 3D engine like you describe, you would use one RISC (let's pick the DSP) to do all the 3D math. The other RISC (the GPU) has to babysit the blitter full time. This is because the blitter can't draw polygons, only spans, and requires full RISC attention to do that task at top speed.

 

On the PS, the 3D math is performed by the GTE and complete polygons are drawn by the GPU. Both of these systems function without RISC intervention (using DMA lists).

 

The GTE is about 3 times faster than the DSP at 3D math, and it has a 133MB/second bus interface, while the DSP has 8.8MB/second. Let's say your 3D math only needs 4MB/second (to read models and emit polygon lists).

 

So for 3D math, on the Playstation, you used 3% of the main bus bandwidth, on the Jaguar, you used 50%.

 

Let's look at texture mapping. On the Jaguar, the blitter has a peak texture mapping speed of 2.4M pixels/second in main RAM, or 3.8M/second using GPU SRAM. These peaks requires 100% of the main bus. But you already used 50% for 3D, remember? So that gives the Jaguar between 1.2M-1.9M/pixels second.

 

The PS has a peak texture mapping speed of 33M pixels/second. This uses exactly 0% of the main bus, since the PS has a dedicated video graphics bus.

 

So you can already see that for texture mapped graphics, the Jaguar is at a severe disadvantage. But we don't have a game yet...

 

Game logic in most 3D titles is complicated. Collision detection in particular is very CPU and bandwidth hungry. So far we've used 0% of the PS's RISC and 3% of the main bus bandwidth. On the Jag we've used 100% of both Jag RISCs and 100% of the main bus.

 

On the Jag, we can't use the 68K because it cannot run in parallel with the RISCs. We probably can't use the DSP for game logic either, because the DSP uses too much main bus capacity and we need all of that for graphics. We could try the GPU, but the blitter can't run when the GPU is doing something else, so there is no way to run graphics in parallel with the game logic.

 

So while game logic is 'free' on the Playstation, on the Jag we are cutting deeper into precious graphics time. Even if we optimize our game logic to need only 30% of one RISC, that's the difference between 12FPS and 7.5FPS.

 

And don't forget sound. The Playstation has a dedicated sound chip with a dedicated bus, so sound playback uses no main bus bandwidth and no CPU. On the Jaguar, you need both. A good multi-channel digital audio system will shave another 15% off the Jag's capacity.

 

Not to mention video! You have to output your frame buffer at 60FPS. Assuming 320x240 in 16-bit color (used by most Jag and Playstation games), you need another 5% of the Jaguar's main bus. The PS has yet another dedicated bus for this function, so it does not consumes graphics bus, sound bus, OR main bus time.

 

So the difference between a graphics demo and a game is ~30%+15%+5% or 50% on the Jaguar! All these costs are hidden with dedicated subsystems in the Playstation.

 

It's rumored that AvP ran smoothly as a graphics demo on the Jaguar, but as they added game logic and sound, it slowed down considerably. The Playstation does not take that kind of hit.

 

My intent is not to put the Jaguar in a bad light. It was designed and released 18 months before the Playstation, which is a full technology generation by Moore's law. Also, Sony absorbed a huge loss on each Playstation sold, while the Jaguar was sold at a profit.

 

If you consider all the technical limitations of the Jag, the 3D games we have are marvels of software engineering. There is probably not a lot of performance left untapped. Of course you're welcome to try. The dev tools are free!

 

- KS

 

 

You know coming from the Fantasy box thread and finding this one it moved me to say kskunk really has described the Jag and its associated limitations extremely well here.

[JagChris]

 

It's rumored that AvP ran smoothly as a graphics demo on the Jaguar, but as they added game logic and sound, it slowed down considerably. The Playstation does not take that kind of hit.

 

 

- KS

 

It's also rumored that:

 

1. AvP uses mostly the 68k in everything it does

 

2. Rebellion is a bunch of morons whom if I owned a console company I wouldn't touch them with a ten foot pole.

 

3. Rumor #2 I started. ITS ALL ME BABY!! YEEE HAAAAA!!