RSX: Vertex input limited? *FKATCT

Judging by what others have been saying about multiplatform games, what you are saying is definetely not unique. Even games like FN3, which spent a long time in PS3 (~ 9 month longer dev time?) centric development, came out looking worse overall than their Xbox360 equiv. Edit: Many multiplatform game looks better on Xbox360. Yes one could argue that it was a difference in development time, but the point is that at this point most games out on X360 perform better and/or have more complex assets (maybe excluding Ridge Racer 7) than the same games (or increase quality in one area at the expense of another ala FN3) on PS3. And PS3 devs have, for all intents, had similar time to develop those games.

I don't know why nAo is implying that this isn't the case.

 

These "other devs" are from major studios that have just as much credibility as nAo. Google is your friend in this regard; i'm not going to data mine for you. I believe many of us have read comments from devs other than nAo and joker, and the general sentiment seems to be that X360 may have a better GPU (tho not in all cases) and PS3 has a better CPU (tho again not in all cases; for example Assasin's Creed Dev team said AI code is faster on X360).

As far as info on Cell vs info on X360, I'm not sure why that was brought up, but I believe that the public info out there is pretty indepth for both systems. And X360 weaknesses have been brought up many times in these forums and in others (in fact probably more than PS3's, as up till launch people assumed that PS3 would win or tie in all catagories).

Again, I'm not attacking nAo, I'm just trying to figure out why his word is final in these matters. He has produced a great looking game, but not only is that game (as far as we have seen in previews) not head and shoulders (that point is arguable, some may find it to be better looking others worse, as compared to x360 games) above x360's best, he has only developed on the one platform.

 

because he developed game for the PS3 and he KNOWS the in and out of the system more comprehensively compared to the other developers.

 

I was purely speaking on what I've read on Beyond3D, and on sites that have been posted here. Feel free to post some of your data mined devs because I'm sure theres people apart from me who would appreciate it. Helios, deanA,DeanOC, Vyzec, nAo, and the other devs whom I forget to name are the ones I was referring to as B3D people who seem to be neutral in discussing GPU merits. In terms of on the net interviews, I'm not sure if theres any one side being leaned on.

I brought that up because I feel nAo is offering insight on how a piece of equipment that at least been partially released to the public, benches against, for all most people know, a paper tiger for which we have the released specs and fullstop. I trust that many of us believe relatively speaking, info on X360 is much scarcer than that of CELL and RSX. For instance, who has benched the CPU on a X360 and has posted on it. This is not really something that needs debate.

 

X360 benchies are not available, that is true. As far as deanA,OC, and nAo, don't they all work together on the same team producing the same game on PS3? I'm not saying that invalidates their opinions, and certainly they can provide great insight to PS3's relative strength, but when it comes to a comparison between the two systems, I don't think their opinions are the only ones we should consider. That's all

 

Of course, which is why I mentioned other devs.

 

How many games are vertex limited though? I thought games were generally TMU limited or shader limited? Or would throwing away unneeded vertices also reduce what needs to be shaded/textured?

He's a first (or 2nd?) party dev right? So he's probably put considerably more work into the PS3 than other devs and knows its ins and outs much better. However, I don't think you could say the same about his 360 knowledge. He may be able to debunk what other devs say about ps3 (saying you can't get good performance for something when there is in fact a way), but is he more qualified than a multiplatform dev in saying that 360 can or can't do something better than ps3? That said, I think he's been cautious on his 360 statements and left them as possibilities (ie: there's some type of code that the 360 will run like crap but the ps3 will handle better) rather than a specific example (ie: 360 can't handle as many pixel shaders at once as ps3).

 

edit:

Dude I think you are just trying to argue for argument sake. Other devs have talked about both systems, and joker's sentiments have been reflected. Aka, Xenos has some benefits over RSX, unified architecture is nicer, x360 has more available ram, xenos can deal with vertex loads better. A dev doesn't have to post in b3d forums to be reliable (aka many have come out both officially and anon. saying these things), and no one would argue otherwise.

edit2: On the other hand so have a lot of nAo's remarks about PS3. I'm just trying to bring up the possibility that nAo's opinion on the x360 is not completely impartial. Some of his comments about X360 and GOW give me the ol' competition between studios vibe . Not saying he isn't a very talented PS3 developer. And I'm certainly not trying to argue that the PS3 is a bad piece of kit. The question is how good is it compared to its main competitor and why.

 

We've gotten around the split memory issue, but in our case we're seeing far less memory free in general. Out of the entire 512mb in each machine, both Sony and Microsoft reserve some for assorted reasons. We have somewhat more free memory on 360 for some reason. Maybe this is just due to the sdk's we're currently using, I'm not sure. Whatever the case may be, we maxed out memory on 360 so that left us scrambling for ways to free memory to get it to fit on PS3. Do you guys see this? I've always been curious if its just us that's seeing less free memory on PS3.

This one interested me because we're actually seing the opposite. We actually had a very specific case to deal with where a cutscene was running slower on PS3 and we tracked it down to being pixel shader bound. It was using a 'crazy expensive' pixel shader which stressed even the 360, but it was able to maintain 30fps. Hard to say for sure why we're see different results though.

We do Although we are definitely not using them as effectively as we could. We're only using 1 spu at the moment as well. Shamefull, I know ;( But, I plan to devote a chunk of 2007 to making better use of threads on both PS3 and 360. My current thought is to make numerous 'threadlets', each being an extremely simple process that has one specific purpose, and snoozes and waits to be fed data for processing. We'll definitly be making full use of the spu's in '07.

 

I hope so. Although we got our PS3 dev kits waaaaaaay after first parties did ;(

 

That "better AI on 360" was debunked already.
http://ps3land.com/article-820.php
Besides, sweeping generalization like yours is not very suitable for B3D discussion IMO. One can argue the both GPU and CPU in the PS3 are worse because RSX needs the help of Cell and Cell is more difficult to code for. This disadvantage does not equal the performance capacity of the hardware itself. It's due to economic/human problems that they can't put enough monetary/human development resources for the R&D in the early stage of the PS3 platform.

Cross-platform devs are doing ports for economic reasons of dev houses. In other words they are forced to support very different architectures by diluting some aspects of their game design, or by putting the priority on the platform with a larger install base. Though this extra pressure is not essential for developing games, it affects cross-platform developers' point of view.

 

This is a generalization. It is due to difference in ease of development (dev tools + hardware) as well as the dilution of resources you mentioned. I believe joker already talked about this.
Didn't know that the AI rumour was "debunked". As far as I remember the dev stated that AI code was easier to implement. It has been stated numerous times that branch intensive code like AI is easier to implement on Xenos. Not my opinion. I never stated that I read that AI would be different for either version btw (reread my post).

 

Please reread this thread and specifically the links in the OP, where said poster himself noted issues (e.g. Xenon related issues, tiling, etc).

I know some of you believe this stuff (everything is always anti-Sony/MS), and there are definately leanings in certain areas among different posters, the reality is people tend to amplify the negative they dislike and ignore the kudos they agree with.

I do have to chuckle though about your 360 comment because in the last year we have had swarms of threads (not just posts, but threads) about lack of AF, lack of MSAA, draw call overhead, broken tiling APIs, thread swapping latency, inability to MEMEXPORT and Tile, and so forth.

Cell and Xenos, both, take by far the biggest lashings -- but also the biggest praises -- on B3D. RSX and Xenon, due to the lack of disclosure by Sony and MS, respectively, has kept discussion on both to a lower degree than the other two, although I think we have a lot better understanding of Xenon now than 12 months ago and I think MOST have come to the realization of what RSX is (although a little late for any interesting discussion).

I think fans tend to pit extremes too often.

The reality is that for multiplatform development, and the issues multiplatform devs face codeveloping a titles for 2 or 3 platform targets and typically under tighter annual deadlines and funding restrictions are quite different from flagship AAA 1st party title.

Neither position invalidates the other, they are just different. A perfect example will be Motorstorm and Heavenly Sword. They will be some of the first games (along with Resistance) to use a bit of the SPEs. Thus far multiplatform devs, due to the nature of the industry, have not had that luxury. What is a perk to one is neutral to the other.

And these sorts of check and balances vary greatly, not only based on exclusive/multiplatform, but also the type of game and technology you are trying to leverage.

IMO, what observers may best glean from this discussion (hopefully it stays calm) is that the hurdles, troubles, and difficulties of development for some 3rd parties is different than those from some 1st parties. Some of the things will be absolutely true for all developers within a confined context, many won't.

Personally, from a business standpoint, I find the opinions of 3rd and 1st parties interesting because their business models are so very, very different and compete and coexist in the same market, but by doing things very differently.

I am not a developer, but from my browsing I think their are two main culprits most agree on:

1. Framebuffer. Since the eDRAM does all the heavy lifting for the buffers the GDDR3 pool primarily holds the finished framebuffer itself. On the PS3 your 720p 4xMSAA framebuffer is going to be about 30MB, on Xenos much of that data is stored on the eDRAM and tiled in to the system memory.

2. OS. Hard to get any hard figures from MS or Sony, but it seems nearly absolutely certain that the PS3 operating system is a bit larger than the Xbox 360 operating system.

I think those would explain your available memory resource differences. Those and different storage formats and such which you already mentioned.

I think the reality is depending on your enigne and shader code the 360 or PS3 can come out on top. Which would come out on top, most regularly, would be hard to tell even in an "ideal" world because even if one of the two chips was faster on 7 out of 10 shader codes, who is not to say that the 3 of those 10 are more common or important (in general or to a certain games design)?

We run into this problem all the time when benchmarking applications. What is better, GPU-A that edges out GPU-B by 5% in 7 out of 10 games, or GPU-B which edges out GPU-A by 25% in 3 applications? And when you dig deeper--like how many of those situations were at 30fps or below, and so forth--can make crowning a winner very difficult.

And the reality that you guys have hit on is there is more than 1 way to skin a cat. As you guys dig deeper into the consoles some of the different architectural decisions as well as featuresets may become more relevant. You may even find that to get a similar end result on screen you take competely different approaches and different technologies to get there. Personally, I expect over the next 2 years to hear stuff like, "We did ABC on an SPE" with a response, "We just used vertex texturing to do that on Xenos" and "We used tesselation on Xenos for this" with a response, "We didn't need RSX to do that because we did it on an SPE".

What really will matter is how the tools and hardware MS and Sony gave all of us makes for better games. The PS3 and Xbox 360 are so similar, yet frighteningly different. But in general performance envelope they are in the same general ballpark and most games with some adjustments will run on either, and should quite well. Of course, as your original thread vented and hit on, the time frame differences and price disparities and the obvious ****** attraction of every microcosmic event really blow things overboard and can make the discussion process, even in friendly disagreement, an act of frustration at times. For that I deeply feel bad for you devs! Almost as bad as I feel for myself

I think I can speak for everything when I say we appreciate having another developer here, especially a multiplatform developer (not many of those here who are vocal) and one who has worked on the Xbox 360 (before a couple months back ERP was pretty much it, but Cal and Fran have joined recently, but that is still a very small number compared to the number of PS developers here). Hopefully goodwill will prevail in the coming year and we can all learn something new, even if we have to agree to disagree.

It will be interesting to hear the results. SPEs are 'crazy fast' when you lean on their strengths. Please keep us updated for the sort of algorhythms you get up on the SPEs. It would be very neat to read a developer diary discussing the development process in detail, hurdles, false starts, restarts, and accomplishments (and dare I say compromises, corners cut, and failures) that occur from the planning, to designing, implimenting and finally to shipping stage.

Alas I am afraid that is a time consuming project and probably would not be NDA friendly.

 

I was only able to make it through the first paragraph before my translation part of my brain fried. I think I agree though

 

Your entire post was very well written. Glad to see how this thread turned out and to see more light shed on the truth between both systems. This is why I like to lurk here. A special thanks to Joker454 and the way you responded within this thread. If you never post here again thanks for breathing new life into the subject of console gaming in the B3D forums.

 

I've heard people say that Sony's OS reserves 64MB more ram than MS's. Additionally, ps3 doesn't have edram so it should have slightly less ram than the 360 anyway.

 

Damn... this thread really filled out in the course of my commute home from work.

Well, I'd think that much is a given because of the fact that there's just the framebuffer in VRAM as opposed to eDRAM and a split pool meaning there's probably some stuff allocated in both pools for the OS. In general, the PS3 OS is just plain bigger, but I'd have a feeling most of that reserved RAM at the moment is for "yet-to-come" features. I can only see Sony piling on more.

Hmmm... well, in my case, I've been working on a pretty massive set of tools for generating shader code from artist input in a graphical layout tool -- it's akin to what Unreal has for materials, but we let artists control a broader scope and also share their work more easily (basically everything that isn't "fixed function" for our purposes, the artists control). In any case, that ultimately means that the largest real estate in our shaders is full of independent fragments in their own macros/functions many of which have a nice mix of vector and scalar ops (or at least you'll have a mix of code fragments some of which are mainly vector ops, some mainly scalar ops), which makes the compiler very happy (though very slow to build) when it comes to optimizing. Everything pairs up nicely for co-issues and also gets both the (mini-)ALUs in each pixel shader pipe working pretty effectively in concert for almost every cycle. We also tend to use a lot of FP16 operations in our shader code wherever it works out usefully, which the Cg compiler optimizes into using certain "trickery" native to the RSX. The 360's HLSL compiler casts them all to FP32, so no harm done.

I don't know what you qualify as 'crazy expensive', but we have little trouble maintaining 120 fps on both machines even with shaders of a few thousand instructions and 8 textures minimum on everything. Can't say that we approach the 5-figures range yet, though.

I may eat my words when we actually get around to constructing *real* levels (as even our most complex levels at the moment are all mainly proof-of-concept creations), but for the most part, it's the software side of things that is the bigger hurdle for us. Rendering is still not a big concern -- the GPU is still very underworked as it is.

 

Isn't it true that sometimes Ati hardware is better a handling certain shaders and sometimes Nvidia hardware is better at handling certain shaders. Couldn't it be that your shaders are just more friendly to Ati hardware. I'm sure there are going to be games that pixel shaders are so optimized for the RSX that the Xenos would have alot of difficulty running them.

 

i agreed and that is why i did not say that the ps3 version is outright superior but i just want to suggested that the 360's version was not an outright superior compare to the ps3's version.

 

Why do people feel easier = more powerfull!?

Yes, the Xbox 360 dev tools maybe more flexible and rich than PS3 tools, but that doesn’t equate into having better hardware (Xbox 360). More or less it represents Microsoft already proven strengths, which is software development. So I can picture certain amount of developers stating and feeling the Xbox 360 is easier, faster, in getting better port-to-port code.

That being said, that doesn’t equate into the PS3 hardware being crippled or flawed by RSX GPU. Many developers have stated that the PS3 tools are a whole lot cleaner and more intuitive this time around, compared to the PS2 tools when they were released. And as some have said, the PS3 tools will only get better and become more refined as time passes.

So if nAo and the rest of the Ninja Theory clan aren’t seeing or experiencing any of these PS3 issues (not enough memory, memory bandwidth issues, RSX stalling, ETC…) which other developers maybe experiencing, then the Ninja Theory team should be commended. Developer’s who write their own straight to the mantel PS3 code, will undoughtedly yield better results than a developer porting multiplatform Unicode. And the same applies to the Xbox 360.