Why to people say that the Xbox GPU is better than the PS3 GPU?

[Doopster]

Honestly I'm not trying to start a war but it seems everyone agrees that the Xbox GPU is faster but I don't see how.

Clock for clock the nVidia 7800 series was quite a bit faster that the x1800 series from ATI.

The PS3 GPU has a faster clock than the Xbox GPU.

So how could there be any dispute that the PS3 GPU has more theoretical horsepower?

Sure the x1800 had unified shaders but that didn't make it faster it just made it more flexible. Flexibility isn't actually that useful in a game console GPU.

Also the Xbox has on die memory but again this doesn't add rendering power it just adds memory bandwidth for anti aliasing.

Anyway not trying to upset anyone I just thought that the above was some pretty obvious facts.

 

[Mike Gayner]

It's not a matter of opinion - the Xbox 360 GPU is a lot faster than the PS3. There's a lot more to GPU technology than just clock speeds. Also, the X1800 doesn't have much in common with the GPU in the Xbox 360. I suggest you read some of the very good articles out there, starting with this one.

Here is some key info about the GPUs:

PS3:
500MHz
24 Pixel Pipelines
8 Vertex Pipelines
250M Polygons/Sec
12G Texels/Sec
8G Samples/Sec
20.8 GB/s Memory

Xbox 360:
500MHz
48 Unified Pipelines
500M Polygons/Sec
8G Texels/Sec
16G Samples/Sec
10MB Buffer (256 GB/s)
22.4 GB/s Memory

 

[crisium]

Thanks to the Cell CPU though, the 360 cannot match the PS3' visuals. Killzone 2 and Uncharted 2 look better than anything on 360. Something about twice as many CPU cores as the competition helps.

 

[Fox5]

The ps3's gpu is a much weaker gpu than the 360, at least in shader ability. Thankfully, the cell is powerful enough to make up for that somewhat, at the cost of being a pain to program. (I'm assuming it can't run opengl shaders, so a lot of functionality probably has to be duplicated onto the cell that would normally be handled by apis)

The ps3's gpu is an off the shelf pc gpu.
The 360's gpu was custom made for consoles. It uses a dual die approach, with a second die consisting of super fast 10MB of edram. This allows the 360 to target either SD resolution with 4x AA or 720p with plenty of usable bandwidth for special effects, lighting, and anti aliasing. The 360 gains a lot from having its gpu designed to target TV resolutions, and its gpu is more forward thinking/advanced anyway.

I read an article a while back that detailed the costs sony and ms put into their respective systems.
MS spent something like $100 million on their cpu (about what nintendo spent on the gamecube's cpu iirc)
Sony spent $2 billion on Cell.
MS spent ~$1 billion on their gpu.
Sony spent around $100 million on theirs.

Basically, MS has an off the shelf cpu fitted to their system with a custom gpu.
Sony has a custom cpu with an off the shelf gpu fitted to their system. The ps3 also came out a year later, yet manufacturing hadn't improved any (same process nodes), so both use hardware from the same generation of manufacturing tech.

The 360's cpu is about the size of a dual core.
The ps3's cpu is about the size of a quad core.
The ps3's gpu is larger, if you discount the secondary die of the 360.
Both the 360 and ps3 gpus are about the size of current high end integrated graphics, but with better memory bandwidth.

 

[Kabob]

Both get the job done, the 360 is just easier to program for. Yeah, it may be a bit faster but (personally) I can't tell much difference (and I'm a 360 guy).

 

[Cogman]

Thanks to the Cell CPU though, the 360 cannot match the PS3' visuals. Killzone 2 and Uncharted 2 look better than anything on 360. Something about twice as many CPU cores as the competition helps.

It also hurts, a LOT. The Cell processor doesn't just have an 8 core processor, it has 1 general purpose processor and 7 floating point crunchers. Now, given the right environment, this isn't a bad thing. If you have huge amounts of floating point information that you need to crunch, then the cell is a great way to go.

The sad thing is, games, while more floating point intensive then other applications, are not completely bound by floating point calculations. Further more, they are not easy to develop to begin with.

Cell is hard to program for (I mean, come on, they have a "prepare to branch" instruction...), And from everything that I've heard, sony's SDK was pretty crap when it was first released (This may have changed). So coupling a difficult to program for CPU with a bad SDK, and then wondering why nobody wants to develop games for your console, sorry, I don't have any remorse for them.

Now, cell can boast some pretty big numbers compared to most CPU's, but it does that at a cost. it was specifically design for high bandwidth, high latency operations. Think SIMD on steroids. However, that 100GFlops doesn't buy you anything if your data isn't in a nice sequential row. Whats worse is it is specifically designed for SP Floating point ops, It can do double, but with an order of magnitude penalty.

The cell is a good processor, but I don't think its premier should have been in a game console. (This is evidence by the really quite sad fact that one of the most popular programs for this game console was F@H)

Ok, I'm done with my OT rant... Just thought you would like to know why bigger is not always better.

 

[RyanPaulShaffer]

It also hurts, a LOT. The Cell processor doesn't just have an 8 core processor, it has 1 general purpose processor and 7 floating point crunchers

That's if all of the cores are turned on, which IIRC, at least one of the cores is turned off at the factory in order to boost the yield levels to an acceptable amount.

The Cell is a great general purpose processor, but it is ill-suited for games.

 

[Cogman]

That's if all of the cores are turned on, which IIRC, at least one of the cores is turned off at the factory in order to boost the yield levels to an acceptable amount.

The Cell is a great general purpose processor, but it is ill-suited for games.

It isn't a good general purpose processor, it is a good floating point cruncher. It kind of sucks for general purpose processing.

I looked it up, it looks like it has a total of 8 SPE's with 1 general purpose processor. Like you said, one is disabled, so 1 general purpose processor + 7 SPE's

 

[RyanPaulShaffer]

It isn't a good general purpose processor, it is a good floating point cruncher. It kind of sucks for general purpose processing.

I looked it up, it looks like it has a total of 8 SPE's with 1 general purpose processor. Like you said, one is disabled, so 1 general purpose processor + 7 SPE's

Ah...thanks for the info. I had always heard that for a regular computer or server or whatever, the Cell was great, but for a specific operation, such as games, the Cell was not so hot.

 

[Doopster]

PS3:
500MHz
24 Pixel Pipelines
8 Vertex Pipelines
250M Polygons/Sec
12G Texels/Sec
8G Samples/Sec
20.8 GB/s Memory

Sorry Mike but I've found a reasonably reliable source that says your 'facts' about the PS3 GPU are wrong. http://en.wikipedia.org/wiki/RSX_%27Reality_Synthesizer'

Also if the Xbox GPU has 48 unified shaders that makes in X1900 class chip. Take a look at this article and tell me if you think a 500mhz X1900 is faster than a 550mhz 7800.
http://www.theinquirer.net/inquirer...00-xtx-kicks-nvidias-7800-gtx-512-in-the-nutz

 

[Fox5]

Sorry Mike but I've found a reasonably reliable source that says your 'facts' about the PS3 GPU are wrong. http://en.wikipedia.org/wiki/RSX_'Reality_Synthesizer'

Also if the Xbox GPU has 48 unified shaders that makes in X1900 class chip. Take a look at this article and tell me if you think a 500mhz X1900 is faster than a 550mhz 7800.
http://www.theinquirer.net/inquirer...00-xtx-kicks-nvidias-7800-gtx-512-in-the-nutz

Err, the x1900 wins most of those...and the conclusion of the article says it does too.

But anyhow, the x1900 didn't have unified shaders. I'd say both the xbox 360 gpu and the ps3 gpu are cut down from their desktop counter parts, as they've generally sacrificed memory bandwidth and fillrate for shader power.
In which case, the xbox 360 gpu was barely midrange for its time in fillrate, but comes with more bandwidth than even current cards (for certain tasks, otherwise it still has more bandwidth than any card at the time), and has way more power for pixel shading or vertex shading (but not necessarily both at the same time) than any of its contemporaries did.
The PS3 gpu is practically integrated graphics as far as bandwidth goes, fairs better on fillrate (notice the 7800gtx's win in doom 3, which is a heavily fillrate limited game thanks to its shadowing), and still falls way behind in shading power.

 

[Kabob]

Sorry Mike but I've found a reasonably reliable source that says your 'facts' about the PS3 GPU are wrong. http://en.wikipedia.org/wiki/RSX_'Reality_Synthesizer'

Wikipedia as a "reliable source" = massive fail.

 

[Mike Gayner]

Sorry Mike but I've found a reasonably reliable source that says your 'facts' about the PS3 GPU are wrong. http://en.wikipedia.org/wiki/RSX_'Reality_Synthesizer'

If you have a reliable source, please post a link to it.

Also if the Xbox GPU has 48 unified shaders that makes in X1900 class chip. Take a look at this article and tell me if you think a 500mhz X1900 is faster than a 550mhz 7800.
http://www.theinquirer.net/inquirer...00-xtx-kicks-nvidias-7800-gtx-512-in-the-nutz

OK so obviously you missed my first post - THE XBOX 360 GPU DOES NOT HAVE MUCH IN COMMON WITH A X1800. The same is true of the x1900.

 

[erwos]

Honestly I'm not trying to start a war but it seems everyone agrees that the Xbox GPU is faster but I don't see how.

Anyway not trying to upset anyone I just thought that the above was some pretty obvious facts.

Whenever you have to begin and end with "not starting a flame war", thou doth protest too much.

 

[MStele]

What's sad is it really doesn't matter in the long run. Both systems are handicapped with a low amount of ram. The PS3 has 256MB system member and 256MB GPU memory and the 360 has 512MB shared. Regardless of how fast they are, they are limited to how large a texture load they can carry. Note that each has 512MB total ram and yet still has to run games. This is the major limiting factor as to why so few games are 1080P native (upscaling doesn't count). 1920X1080 textures take up alot of memory and neither console has memory space for them.

 

[sygyzy]

I am extremely impressed with how much you guys know about console CPU/GPU and development!

 

[Mike Gayner]

What's sad is it really doesn't matter in the long run. Both systems are handicapped with a low amount of ram. The PS3 has 256MB system member and 256MB GPU memory and the 360 has 512MB shared. Regardless of how fast they are, they are limited to how large a texture load they can carry. Note that each has 512MB total ram and yet still has to run games. This is the major limiting factor as to why so few games are 1080P native (upscaling doesn't count). 1920X1080 textures take up alot of memory and neither console has memory space for them.

Texture resolution =/= display resolution.

 

[Kromis]

Thanks to the Cell CPU though, the 360 cannot match the PS3' visuals. Killzone 2 and Uncharted 2 look better than anything on 360. Something about twice as many CPU cores as the competition helps.

LOL what? How the hell is this relevant? We're not talking about visuals, we're talking about the hardware itself. Flame bait right here.

 

[crisium]

Much more relevant than your post.

It's a way to explain how the PS3 can be more powerful than the 360 overall, despite having a slower GPU. And it lead to our good friend Fox5 sharing interesting facts on GPU/CPU spending by MS and Sony. Luckily don't have to limit discussion based on your own short sightedness.

 

[MStele]

Texture resolution =/= display resolution.

That's exactly my point.

 

[Fox5]

Much more relevant than your post.

It's a way to explain how the PS3 can be more powerful than the 360 overall, despite having a slower GPU. And it lead to our good friend Fox5 sharing interesting facts on GPU/CPU spending by MS and Sony. Luckily don't have to limit discussion based on your own short sightedness.

Reference: The Xbox 360 Uncloaked by Dean Takahashi

 

[Kromis]

Reference: The Xbox 360 Uncloaked by Dean Takahashi

Thanks for bringing that book up. I've always wanted to check it out but I totally forgot about it!

 

[Doopster]

If you have a reliable source, please post a link to it.

You post your source on the PS3 GPU that backs up your original specs. Wikipedia is more reliable than any random tech site with the exceptions of the big ones like Anandtech.

Err, the x1900 wins most of those...and the conclusion of the article says it does too.

Yes it does win but at 625mhz clock speed...

I was wrong about the x1900 having unified shaders sorry about that. Still I feel the comparison between the 48 shader x1900 and 7800gtx is valid.

Still I'd love to hear more about the magic and pixies that makes the Xbox GPU much faster than the ATi parts that came out nearly a year later and at much high clock speeds.

 

[Mike Gayner]

Doopster, you are clearly a fanboy. Personally, I don't give a crap about either console. But the speed of a given GPU has absolutely nothing to do with your desire or fanboyism. The Xbox GPU is faster. It's as simple as that. Why do you have such a hard time swallowing this?

 

[zerocool84]

You post your source on the PS3 GPU that backs up your original specs. Wikipedia is more reliable than any random tech site with the exceptions of the big ones like Anandtech.



Yes it does win but at 625mhz clock speed...

I was wrong about the x1900 having unified shaders sorry about that. Still I feel the comparison between the 48 shader x1900 and 7800gtx is valid.

Still I'd love to hear more about the magic and pixies that makes the Xbox GPU much faster than the ATi parts that came out nearly a year later and at much high clock speeds.

Just an fyi, clock speed means next to nothing in today's world when comparing different components from different companies.