Real PSP performance numbers
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"cooked"? Not sure what you mean by that, other than the fact that chip capabilities were released (rather than real-world estimates sans one if I recall correctly). In other words, what do you want to know exactly?
- what the PSP is pushing currently on 1. Generation software? (I don't think any PA numbers are available)
- what PSP could push given certain circumstances?
- what PSP should be pushing with 3rd generation software?
- what the PSP is pushing currently on 1. Generation software? (I don't think any PA numbers are available)
- what PSP could push given certain circumstances?
- what PSP should be pushing with 3rd generation software?
Sony quoted the following performance numbers:
664 M pixels/sec
max 33 M polygon /sec(T&L)
Now given a 480x272 screen, you could theoretically fill the screen 5000 times / second. Given your 60 frames per second screen update rate, you could have 84 layers of pixels on the screen. The content I have seen is about 3-4 layers max, meaning that approximately 31M pixels/sec are actually rendered. This about 1/20th of the performance Sony has boasted.
Same with triangles. I estimate about 20-30k triangles/frame on current PSP games. Now at 60 FPS you get a max 1.8M polygons/sec. This is also about 1/20th of the marketing numbers.
Don't take me wrong, the games look great, it's just that the content does not match the numbers Sony has published. Can we then expect 20x more complex content on PSP later on? I doubt it, so most likely the real performance numbers are much less than what have been announced.
664 M pixels/sec
max 33 M polygon /sec(T&L)
Now given a 480x272 screen, you could theoretically fill the screen 5000 times / second. Given your 60 frames per second screen update rate, you could have 84 layers of pixels on the screen. The content I have seen is about 3-4 layers max, meaning that approximately 31M pixels/sec are actually rendered. This about 1/20th of the performance Sony has boasted.
Same with triangles. I estimate about 20-30k triangles/frame on current PSP games. Now at 60 FPS you get a max 1.8M polygons/sec. This is also about 1/20th of the marketing numbers.
Don't take me wrong, the games look great, it's just that the content does not match the numbers Sony has published. Can we then expect 20x more complex content on PSP later on? I doubt it, so most likely the real performance numbers are much less than what have been announced.
ddes said:
Sony quoted for the most part performance figures of the corresponding chips.
ddes said:
that's the Fillrate of the 'GPU' and what's more or less available for developers to use...
ddes said:
a figure not much different than the 'perspective transformation' number of the EE. A number that shows the performance under strict circumstances.
ddes said:
Fillrate isn't just used to draw visible pixels on screen...
ddes said:
the 33 Mpps number isn't indicative of what the PSP as a piece of hardware will push - it's a mear number derrived by the chips ability to push triangles, nothing more.
ddes said:
20x more is unlikely, but specs will improve. Current 1st generation titles are likely rushed, not using the hardware very efficient on premature libraries. The PSP will be pushing more once battery issues are sorted out and developers get confortable with the hardware. To put things into perspective, PS2 didn't push much more than 1 to 2 million polygons/sec with first generation software either... yet over time, it was able to increase this number to 7 and much more than that with certain tradeoffs. Give it some time.
Megadrive1988
Veteran
version said:
ack, no way. PSP most likely has 4 pixel pipelines, not 8. so that gives it 668 megapixels/sec fillrate. and *that* gets cut in half to 334 megapixels/sec when texture mapped, filtered pixels are used.
edit: admittedly I could be wrong, and you could be right. here's why. the original fillrate was indeed 668 megapixels/sec. it was originally assumed that was with texture mapping+filtering. if that was right, then PSP could have a 'raw' untextured fillrate of 1336 megapixels, thus your 1.3 gigapixels. which would mean PSP has 8 pixel pipelines/engines much like PS2 has 16. then PSP would have 4 pixel pipelines when texture mapping, much like PS2 has 8 pipes when texture mapping.
guys which is it?
Panajev2001a
Veteran
Megadrive1988 said:
Why are you assuming that fill-rate always gets to cut in half when using texture filtering ?
PSP does not use the GS, has a new GPU and the rumors so far were that at least bi-linear filtering was "free", that is the GPU could render in 1 cycle a textured pixel with one texture layer which would be the same speed it renders untextured pixels.
BTW, on PlayStation 2 IIRC even point-sampled textures should give you half peak fill-rate as it is still texturing.
What do you call real numbers, exactly? Are theorical numbers, fake/wrong numbers, now?ddes said:
Also , if you expect to have a real world estimation of the PSP capabilities, you should , at least wait a few years, before asking such a question.
Seeing that all we have now are "launch games" (with all the pejorative implications of that phrase), that had theirs developement started on very slow emulators, with weaker amount of RAM (8MB, IIRC, when the final PSP got 32+2+2MB).
Looking for "absolute and comprehensive" real world numbers now, would be like taking Evegrace performance, at the PS2 launch, and then conclude that a game like Jak 3 or R&C 3 is technically impossible on the PS2.
Also, about your "potentials" expectations you could have, if you were a developer; you'd have, then, to understand, that this kind of "problem" is the same for any machines you would program for. "Real world" performance being available or not.
Since there's no such thing as an absolute "real world" performance. Every engine is different, the global performances (polys/per scene, sound, AI, Physic, loadings, etc) of an Engine x for a platformer will vary from the performance of an engine y for a racer, which at its turn will also vary from the performance of an engine z for a racer, which apply cubmap reflection on the cars, etc...
When you're a programer, the first thing you do, with a new hardware/devkit, is to test the ideas, you have for your future engine, on the new hardware, and then make your architecturals decisions accordingly. It's as simple as that.
You won't tell your artist to start modeling x hundreds polygons models, before you get your hands on the devkit, for your GC, or DS game, because Nintendo made "real world-like" performances available, that would be insane.
Vysez said:What do you call real numbers, exactly? Are theorical numbers, fake/wrong numbers, now?ddes said:
Let me simplify even further.
What kind of polygon counts and pixel fillrate PSP users can see today? I just see a discrepancy between Sony's numbers and the numbers you get with a PSP and the latest game you can buy today. And I know the reason for that.
Let me also clarify. This is not a religious war. I am all for PSP, it's great. The engineer in me just wants to know the numbers so I can compare the device with others.
That's pretty much all that counts. Sure, this will be improved but so will everything else. They write magic stuff for Commodore 64 these days you know.
ddes said:
I really don't want to be picky, but further up, I thought you already counted them to be at around 1.8 million pps?
ddes said:
...maybe because you're looking at chip specs and expecting these to equal game performance? :?
Doesn't quite work that way. It's like comparing cars... you know Car A is 1200Kg and has an engine with 200bhp at 7200 RPM and a maximum torque of 230Nm at 3250 RPM. At the end of the day, you know roughly the "specs" of the car and its parts (= specs of the platform) - but there's really no way of concluding how fast it will actually perform on a race track (= real world performance). And even once the first lap is done on the race track, it is still bound to the drivers ability to drive the car (= the developer). What we're seeing here on PSP is simply the first lap with developers that haven't used the hardware before... it will take time to utilize the platforms strength and narrow the gap to the max. specs - no different than a car that requires multiple laps to maximize the car's performance on track.
ddes said:
If you're strictly comparing device A to device B, then looking at performance estimates of the chips is as accurate as you can get. "In-game" performance at the end of the day will always be limited by the developers and the efficiency put into the program. Why take that as absolute benchmark if there's really no way of concluding which developer maximized the engine the most and there isn't more to be squeezed out of the system? How do you quanitify which engine is better, given that each games runs under different circumstances (rpgs, fighter, race)... and that's even ignoring the most important aspect all together which isn't necessarely bound to hardware specs -> art-direction!
Phil said:ddes said:
I really don't want to be picky, but further up, I thought you already counted them to be at around 1.8 million pps?
My opinion yes, so can we conclude that PSP is merely able to do around 2M polys/second while Sony's saying 33M?
No, I'm looking for opinions. Seems that there are none, so let's conclude the discussion here.
Phil said:
So the dealer said the car has 664bhp. So I bought the car. Now it feels like 200bhp. How long do I have to wait to get the full horsepower out of it? Realistically, if I buy a 200bhp car, it feels like it. PSP doesn't and it's not just about software.
Sorry, this was not at all the point of the discussion. I was looking for much more technical analysis of the hardware, that's why the message was originally posted on the 3D hardware forum, not here. I'll continue digging out the information and opinions elsewhere.
Thanks all.
I know I really shouldn't enter this thread but I'm a sucker :?
The machine can render pixels at the stated speed - end of story.
Whether that will be used for filling half the screen every 3 seconds or filling the screen 5000 times per second is up to the people that write the software.
Similar can be said for raw triangle rate. Now you can argue that Sony should have included numbers for cost of hw lights, cost of hw skinning, morphing etc. but I don't recall seeing detailed info of that kind released publicaly for any other console either.
Anyway, to answer your real question - while Sony was nice enough to release pretty much everything about PS2 publically (unlike every other console maker), it's extremely unlikely for that to happen again with PSP. Outside leaks, I wouldn't expect much detailed tech info to get into public.
If you were a developer for PSP you would already know this information.
So if I buy a Ferrari 355 and use it to drive around my hometown 50-60km/h, that means the manufacturer was falsely advertising the car's performance.
The machine can render pixels at the stated speed - end of story.
Whether that will be used for filling half the screen every 3 seconds or filling the screen 5000 times per second is up to the people that write the software.
Similar can be said for raw triangle rate. Now you can argue that Sony should have included numbers for cost of hw lights, cost of hw skinning, morphing etc. but I don't recall seeing detailed info of that kind released publicaly for any other console either.
Anyway, to answer your real question - while Sony was nice enough to release pretty much everything about PS2 publically (unlike every other console maker), it's extremely unlikely for that to happen again with PSP. Outside leaks, I wouldn't expect much detailed tech info to get into public.
Fafalada said:If you were a developer for PSP you would already know this information.
Well I'm not. That's why I'm asking. I do not quite frankly understand the religous aspect of the discussion.
Fafalada said:
No, only if that's as fast as your Ferrai goes.
Fafalada said:
Sure. Nice to see how much people really believe all kinds of marketing information.
Fafalada said:
Sure. I just have a technical engineering interest on how fast the hardware really is and what kind of games we can expect to see. It's just quite typical that games are written to take advantage of the available hardware.
ddes said:
Am i seeing right? I know this will sound very corny, but do you know who you're talking to?Re: Question refrased
Hey i wasn't talking about me. You replied to Faf as if he was "someone who will just believe Sony's Marketing stuff". Hence my question, do u know who he is? Not only he developed Axel Impact for PS2, but there is also a version scheduled for PSP, although i'm not sure he's working on that project.
So, really, if he says something, people tend to just listen to him in this forum. Just a bit of newbie advice.
ddes said:
Hey i wasn't talking about me. You replied to Faf as if he was "someone who will just believe Sony's Marketing stuff". Hence my question, do u know who he is? Not only he developed Axel Impact for PS2, but there is also a version scheduled for PSP, although i'm not sure he's working on that project.
So, really, if he says something, people tend to just listen to him in this forum. Just a bit of newbie advice.
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