Are the new consoles CPU limited?

[SickBeast]

Wouldn't even a 9700Pro be CPU limited in most games today? It's not a very high resolution at all.

It's making me wonder if the PS3 with its more powerful Cell processor will beat out the Xbox 360 using CPU power alone. Seriously, what can a 7800GTX NOT run at 1280x720? I'm sure it would even mangle FEAR without issue.

 

[daniel1113]

No... they are "TV" limited.

 

[Fadey]

uh not really a 7800gtx , the 256 one any way has problems running fear maxed out with softshadows etc or x16 aa , or really x8 even.

 

[Peter]

It's just that the TV sets common today are either 480- or 576-line standard resolution legacy TV, or HDTV units which most commonly are 720-line widescreens.

 

[GOREGRINDER]

so if you have an hd widescreen that supports 720p and you set the output on the xbox360to 720p and are using the component vid cables,...you will see the best the xbox 360 has to offer visually

 

[Peter]

Right.

 

[GOREGRINDER]

thats what makes consoles look good ,....

the system its developed for, is the same system the game will be played in no matter what,.no open ended compatibility,..fixed compatibility

they are developing games for fixed resolutions with fixed widths and hieght formats

and thats what makes them less costly than pc hardware,...they are just beefed up fixed integrated sub-systems

 

[dunno99]

No, all 360 games are required to render at 1280x720 with 2xFSAA (granted there is a rumor going around saying that PGR3 is rendered at 1024x600 and then upsampled in order to maintain 30fps). And because the 360 tries to push shader usage (which some types of shaders require very little CPU intervention, and are also the ones used most heavily), this results in a bottleneck in the graphics subsystem. If the PGR3 rumor has any shred of truth in it, then we know for a fact that we've already reached the limit of the 360's graphics capabilities, since we all know that increasing the resolution places the majority of pressure on the graphics subsystem. And since PGR3 is attempting PR, rather than NPR ((N)PR = (Non-)Photo Realistic), we know that the CPU isn't limiting but also can't help much in the rendering pipeline (360's CPU does about 20-40GFLOPS, and the GPU does about 140GFLOPS...of course, I don't remember any of this and I just pulled out my calculator on some approximations...so don't quote me on it).

On the other hand, the PS3 won't be much better off either, since the G70 GPU has performance around the same ballpark as the 360's GPU (might be better or worse, I don't know...but not too different, that's for sure).

 

[kylebisme]

Originally posted by: dunno99
If the PGR3 rumor has any shred of truth in it, then we know for a fact that we've already reached the limit of the 360's graphics capabilities...

Nah, give them a year or two and there are bound to be great strides in tapping the power of the system, this has been the way it is with every console.

 

[dunno99]

*Sigh*...that's the whole point of my post: there are no new "great strides" to be made with the hardware. Sure, there may be advances in general software algorithms that will improve visual quality, but that applies to all consoles/PCs, and does not in any way negate the fact that the limit of the console has been reached. Put it simply, the GPUs in the next gen consoles are already fairly well known...people programming for Windows have long long since been exposed to them, so there isn't much to "optimize" anymore. It's not as if the GPU documentation and architechture of the 360 is the same as the PS2's (or any GPU architechture different from mainstream OGL/DX hardware)...so there aren't really any "unknowns" to "explore" and take advantage of.

Of course, my arguments all depend on Bizzare's ability to write efficient code (so they don't use O(N^2) code where they could easily use O(NlogN)) in their shaders/rendering engine. But given that PGR3 looks better than all the other games that are coming out for the 360, I think the code is at least half-decent.

So basically, this next gen vs PC war will end rather soon, given that come April, the FX-62 + R580/G80 will beat the pants off of any next gen console. And a year after that, the PC will beat all released consoles in terms of price/performance.

 

[Pete]

Not CPU limited, as consoles will likely be shading most/all pixels on screen (just look at the Perfect Dark Zero gameplay video, just about everything is shiny). Console devs will no doubt make use of all available GPU power, as well as CPU power. The GPU is probably easier to maximize b/c of how parallel it is (one improvement may affect a lot of the screen, using up lots of GPU cycles).

 

[kylebisme]

Originally posted by: dunno99
*Sigh*...

I'm sorry I offended your intelect there, you are right. The Xenos's unified shaders and eDRAM framebuffer is exactly like modren GPUs, the RISC CPU buit to run 6 hardware threads, and the unified memory design of the system all make it nearly identical to what developers are already accustomed to programing for with modren PCs. Being as no different from mainstream hardware as the 360 is, the lanuch games obviously have to be showing the system at it's best; and the 360 will never be able to show anything near the vast impovement that the Xbox has with it's far more unsual Geforce3/Celeron combo. Thank you for helping me see the light.

Oh, and the launch games are not rushed by any means at all either, so there is no reason to account for anything like that.

 

[Todd33]

the RISC CPU buit to run 6 hardware threads, and the unified memory design of the system all make it nearly identical to what developers are already accustomed to programing for with modren PC

No. Developers have a hard time even working with two threads, none of the launch titles use four or six. Developers are used to long pipeline CPUs like the P4 and A64s, not the PPC. MS went cheap with the IBM CPUs, it will take time for developers to learn to use them fully if ever. Same goes with the Cell.

 

[Addle]

Doesn't the XBOX 360 support 1080p?

 

[kylebisme]

The 360 could render at 1080p, but highest avalable output is 1080i at least for now.

And yeah Todd33, my previous post was all sarcasm, there is obviously much to be learned about building games for any new console.

 

[Stoneburner]

So because supposedly the ps2 and Xbox took a while before showing its muscle the exact same thing will happen this generation. Brilliant argument. I'm checking through my list of logical fallacies and I don't see it there. Relying on the strength of an authority? Also not making my list. Your arguments are air tight.

 

[CalamitySymphony]

CPU limited? What are people smoking anyway. Everything is GPU limited. Oh not to mention, the CPUs on these beasts beat the crap out of every other CPUs available currently on PCs.

 

[MrDudeMan]

Originally posted by: CalamitySymphony
CPU limited? What are people smoking anyway. Everything is GPU limited. Oh not to mention, the CPUs on these beasts beat the crap out of every other CPUs available currently on PCs.

are you sure? id like to see some info to back that up. i find that hard to believe the CPU in the xbox can top an X2 4800+ at anything.

 

[darkswordsman17]

Originally posted by: Todd33

the RISC CPU buit to run 6 hardware threads, and the unified memory design of the system all make it nearly identical to what developers are already accustomed to programing for with modren PC

No. Developers have a hard time even working with two threads, none of the launch titles use four or six. Developers are used to long pipeline CPUs like the P4 and A64s, not the PPC. MS went cheap with the IBM CPUs, it will take time for developers to learn to use them fully if ever. Same goes with the Cell.

That was sarcasm on his part. He's saying that since developers are used to much different architecture that there is a lot of ground to be made up through just improving their code.

There's no way you can say that they've maxed the hardware of the 360 yet. Saying PGR3 already has would be ignorant ([Michael Jasckon]thats just ignorant[/Michael Jackson]). Remember that Bizarre isn't accustomed to programming on such an architecture. Even with the similarities between the 360 and a PC, Bizarre hasn't been programming on the PC, and thus they're in a heavy learning stage. Thats why a company like Epic (or whoever is the Unreal Engine 3.0 creators) has a leg up on most console developers because they were expecting such hardware to come into spec eventually and so they just have to adapt their engine to run on the 360 hardware.

Not only that, but I'm sure a lot of these early games are using quite a bit of middleware in order to make the release date. Once they have time to go back and optimize the code more and possibly start some parts over from scratch (instead of patching in a middleware solution) then they should be able to get more out of the hardware. I don't expect most developers to do this, but one's like Rare and Bizarre I would probably expect to.

Besides, how much time did they have with dev kits that actually had finalized hardware in them in order to optimize for them? Not very long. Less than 6 months probably. Considering a really good game typically has a development time of 2-3 years, and that some of these games (Perfect Dark for instance) were almost certainly started back with the original Xbox and it wasn't known when the 360 would be made, or else were developed with a PC architecture that is different enough that they can't really take advantage of the 360's specific strengths quite yet.

I'm not saying that PC hardware won't eclipse it fairly quickly (especially now that dual-core and 64-bit is gaining support), but there's still a lot to be pulled from the X360's hardware.

 

[darkswordsman17]

Originally posted by: Bigsm00th

Originally posted by: CalamitySymphony
CPU limited? What are people smoking anyway. Everything is GPU limited. Oh not to mention, the CPUs on these beasts beat the crap out of every other CPUs available currently on PCs.

are you sure? id like to see some info to back that up. i find that hard to believe the CPU in the xbox can top an X2 4800+ at anything.

Its difficult if not impossible to really compare the CPUs in the new consoles with something like an X2, as they're very different in how they work (well how you tell them to work) and thus, they're more dependant on the skill of the programmer.

 

[Todd33]

Originally posted by: CalamitySymphony
CPU limited? What are people smoking anyway. Everything is GPU limited. Oh not to mention, the CPUs on these beasts beat the crap out of every other CPUs available currently on PCs.

No, they are quiet weak. Games will be hard pressed to keep up with advanced AI and physics among the normal CPU stuff. On the other hand the GPUs are very advanced, disproportionately so.

I sat through a few NDA Cell discussions with developers (software, not hardware). The Cell will be weak as a general GPU but very fast at number crunching (good for physics, bad for AI). The Xbox360 is similar, but weaker at number crunching (no 8 SPUs) but better at general stuff (3 PPC cores not 1). Assuming developers never tap the full six threads at once (that's a tough job), it will just be a PPC like a G5, not powerhouse , but cheaper than a P4 or A64. In the end MS had to get the full rights to the CPU and GPU for cost reasons, so they had to compromise with the IBM CPU.

 

[MrDudeMan]

Originally posted by: Todd33

Originally posted by: CalamitySymphony
CPU limited? What are people smoking anyway. Everything is GPU limited. Oh not to mention, the CPUs on these beasts beat the crap out of every other CPUs available currently on PCs.

No, they are quiet weak. Games will be hard pressed to keep up with advanced AI and physics among the normal CPU stuff. On the other hand the GPUs are very advanced, disproportionately so.

I sat through a few NDA Cell discussions with developers (software, not hardware). The Cell will be weak as a general GPU but very fast at number crunching (good for physics, bad for AI). The Xbox360 is similar, but weaker at number crunching (no 8 SPUs) but better at general stuff (3 PPC cores not 1). Assuming developers never tap the full six threads at once (that's a tough job), it will just be a PPC like a G5, not powerhouse , but cheaper than a P4 or A64. In the end MS had to get the full rights to the CPU and GPU for cost reasons, so they had to compromise with the IBM CPU.

thats what i thought. no offense calamity, but you sound like you just spewed some trash you read online and really dont know how processors work. also, logic should tell you a console that costs 1/3 the price of a processor probably isnt as powerful. :laugh:

i understand there are differences inherent to the design of each processor, but to say they are unrelated is rubbish.

 

[dunno99]

Stoneburner: Hahaha...I'm still wondering which way to take your argument...I guess the subtle vocal nuances for speech isn't apparent in an online forum.

TheSnowman: Sorry about the "Sigh." That wasn't meant as an attack on anyone's intelligence (or didn't mean to invoke any such response). That was merely my response to the fulfillment of my own expectations that someone will eventually (but I didn't expect it to be the next post) point out "give it some time for them to mature" type of counter-argument (which is exactly what I'm trying to point out that isn't true for the 360). The point is that, sure, the 360 has unified shaders where each shader can perform either vertex or pixel calculations...but so what? Some of them will always be configured to be vertex shaders while others will be pixel shaders. The fact remains that ALL of the 48 shaders are used because the instruction dispatches to each of the shader units are automatic. We also know that the game isn't CPU bound or that there is some type of thrashing of memory because the only thing that Bizzare did to improve performance was to reduce the resolution (if it's CPU bound, then decreasing the resolution won't make a difference...also, the texture samples take up the same amount of memory no matter what the screen resolution is)...although higher resolution does take up more space in the framebuffer, but pinning all hopes on that as being the root cause is quite a leap of faith. Moreover, the eDRAM is just that...a fast framebuffer. For comparison, the eDRAM on the 360's GPU package has a throughput of 32GB/s, while the X1800XT 256MB edition has a throughput of 2(for DDR) x 0.75GHz x 32bytes/s = 48GB/s off of the card's main memory. Basically all the developers are coping with is a slower framebuffer than the current high end cards.

Again, I'm comparing the performance of the GPU, not the CPU. I believe I already ruled out that these games are CPU bound (at the moment). And knowing that the entire 360 CPU isn't nearly as good as its own GPU when pumping out pixels, we know that the CPU won't make a lot of difference when we talk about real-time rendering. So while the devs can optimize the CPU code like nobody's business (and resulting in better AI/physics/whatnot), the visual quality won't get major improvements until some new general graphics algorithm comes out of Academia.

 

[kylebisme]

I'm pretty sure Stoneburner was arguing on your side, but obviously he doesn't understand that I wasn't just speaking of the Xbox and the PS2, but pretty much every console, arcade board, or any other piece of gaming hardware that ever existed. Besides, the fact that it is the way it always works wasn't really my point anyway, but rather a side note on top of the reasons why it works.

As for your arguments about Xenos being no different in application that current PC hardware, with that you have exposed the fallacy behind your position. While launch titles have been almost surely designed with your suggested automatic instruction dispatches allocating loads that are similar to what we have in PC games; graphics engines built around the hardware can allow for developers to dedicate far more power to their choice vertex or pixel shading than currently available modern graphics cards.

Also, do you not realize that your comparison between the eDRAM on the Xenos and the main memory on the x1800xt is flawed? The 48GB/s on the x1800xt isn't just framebuffer, the r520 has to run everything though that while the Xenos has a separate bus to the unified memory for textures and whatnot. Most launch games probably were built to use the eDRAM as just a fast framebuffer like you claim it is, but engines built around the console will surely improve efficiency by using the eDRAM to tile back to main memory.

Finally, even if you were right in claiming that the GPU is tapped out already and the CPU is sitting idle, that idle CPU power could always be put to use in adding to the graphics as well. But all that is only a small part of what will make future games better capable of exploiting the power of the hardware compared to the launch titles which bickering over such details rather futile. As with any complex system, understanding the strengths and weaknesses of the 360 will take time and in that time the quality of the graphics will advance accordingly as they have with nearly every piece of gaming hardware in existence.

 

[EightySix Four]

I disagree dunno, there is always much to be learned about the hardware., none of the programmers have ever dealt with a 6 thread 48 pipe unified architecture. I honestly doubt the rumors are true about PGR3, I've played the game, and there is zero slowdowns at all... it's gorgeous. I will look forward to what's to come.