Quake4: Nvidia6800 vs ATI Xenon

[ihamoitc2005]

Blue-ray vs DVD

PS3 with a 50GB BR disc would not be any better. Streaming texture from disc? You must be jesting....LOL

50GB = much more space for textures than DVD no?

 

[Lysander]

Hmmm, that sounds a bit suspicious.

in which way

 

[TrungGap]

50GB = much more space for textures than DVD no?

However, it still need to fit into memory. Because texture streaming from disc is not viable. I'm not saying that the extra space on BR disc won't go to good use, but streaming texture isn't one of them.

 

[zidane1strife]

in which way

Sounds like an excuse or a PR response. If they're having trouble with the h/w or there are problems with their engine, etc this would be the best way to make any such shortcomings sound possitive. Definitely better than the way PGR3's possible 30fps PR was handled.

 

[TrungGap]

edit: dont want to throw this too far off topic.

Doom 3 was running at 60fps on my 6800GT well over 720p res. too. It must have something to do with the texture memory bandwidth?

This is a possibility, since your 6800gt the memory bandwidth (32GB) is dedecated to video, where as x360 (22GB) is shared. Though, there's the edram...sheesh, i just don't know enough...we just don't know enough about q4 say why.

 

[ihamoitc2005]

However, it still need to fit into memory. Because texture streaming from disc is not viable. I'm not saying that the extra space on BR disc won't go to good use, but streaming texture isn't one of them.

Why do you think the textures wont fit in memory?

 

[ihamoitc2005]

bandwidth

This is a possibility, since your 6800gt the memory bandwidth (32GB) is dedecated to video, where as x360 (22GB) is shared. Though, there's the edram...sheesh, i just don't know enough...we just don't know enough about q4 say why.

Are you saying CPU and GPU share 22GB/s to 512MB GDDR3 memory?

 

[swaaye]

We know a few things about both the new consoles and the Doom3 engine that are VERY applicable to Quake 4.

#1. Doom3 engine is extremely CPU dependent.
#2. X360's CPU is an in-order triple core. PCs these days are extremely fast out of order CPUs. In-order means it's going to take a lot more work to get the speed up. And they have to multithread the engine to get the speed up too.

So it's a highly CPU dependent game depending on a highly difficult to optimize for CPU. I think that is the answer.

 

[ihamoitc2005]

Xenon vs P4

We know a few things about both the new consoles and the Doom3 engine that are VERY applicable to Quake 4.

#1. Doom3 engine is extremely CPU dependent.
#2. X360's CPU is an in-order triple core. PCs these days are extremely fast out of order CPUs. In-order means it's going to take a lot more work to get the speed up. And they have to multithread the engine to get the speed up too.

So it's a highly CPU dependent game depending on a highly difficult to optimize for CPU. I think that is the answer.

Perhaps it will be interesting to do a comparison of theoretical P4 and Xenon capability since this can guide us in understanding how effective Xenon is at this time in product cycle.

 

[Richard]

We know a few things about both the new consoles and the Doom3 engine that are VERY applicable to Quake 4.

#1. Doom3 engine is extremely CPU dependent.
[snip]
So it's a highly CPU dependent game depending on a highly difficult to optimize for CPU. I think that is the answer.

One thing that B3D's reviews have shown is that D3 is actually one of the less CPU dependent games today. It's certainly less CPU bound than say, FarCry, which is often described (rightfully so) as the trully first D3D9 game. For instance, on my P4 3.2C paired with a X850XT PE D3 ceases to be CPU bound at 1280x1024 without using AA. And when using 4xAA the game becomes gpu bound right at 1024x768.

So even with a (what is now) a mainstream CPU, ATi's top of the line GPU still becomes the bottleneck without requiring ultra high resolutions. In comparison, FarCry remains CPU bound even at 1280x1024 4xAA/8xAF.

So, while I think you are right about the different in-order/out-of-order architectures playing a part, I think the primary reason is probably the lack of final hardware (by the time these Q4 previews were written) and the fact that Q4 for xbox 360 is a little behind the PC version and will be released later.

 

[ihamoitc2005]

bandwidth

One thing that B3D's reviews have shown is that D3 is actually one of the less CPU dependent games today. It's certainly less CPU bound than say, FarCry, which is often described (rightfully so) as the trully first D3D9 game. For instance, on my P4 3.2C paired with a X850XT PE D3 ceases to be CPU bound at 1280x1024 without using AA. And when using 4xAA the game becomes gpu bound right at 1024x768.

So even with a (what is now) a mainstream CPU, ATi's top of the line GPU still becomes the bottleneck without requiring ultra high resolutions. In comparison, FarCry remains CPU bound even at 1280x1024 4xAA/8xAF.

So, while I think you are right about the different in-order/out-of-order architectures playing a part, I think the primary reason is probably the lack of final hardware (by the time these Q4 previews were written) and the fact that Q4 for xbox 360 is a little behind the PC version and will be released later.

So are you suggesting a total memory bandwidth of 22.4GB/s is insufficient to run Quake4 at 720P? If so, do you think this is in part because of main memory and bandwidth used in tiled rendering from implementing AA?

 

[The GameMaster]

So are you suggesting a total memory bandwidth of 22.4GB/s is insufficient to run Quake4 at 720P? If so, do you think this is in part because of main memory and bandwidth used in tiled rendering from implementing AA?

No because the majority of the most memory bandwidth intensive video functions was removed from the main system memory and instead will be performed on XENO's eDRAM, and that has a *LOT* more available memory bandwidth for those particular functions. Personally there should be *NO* reason why Quake4 on the Xbox360 would have less geometry compared to the PC version as the XBox360 is *FAR* more competent at pushing geometry with XENOS's unifed pipelines compared to conventional PC GPUs, and especially not after some of the games demostrated for the system shown to push *FAR* more geometry compared to the Doom3 engine (examples being PGR3 or Kameo). I tend to think it has to do with the fact the engine was unoptimized for the hardware the XBox360 is using and that will probably be addressed come the final product.

I believe everyone expected that PC ports to the XBox360 would be a bit more problemsome this time around due to the different architecture, and any problems that the XBox360 is having in regards to this PC ports will likely also be reflected on the PS3 for the same reasons.

 

[a688]

So are you suggesting a total memory bandwidth of 22.4GB/s is insufficient to run Quake4 at 720P? If so, do you think this is in part because of main memory and bandwidth used in tiled rendering from implementing AA?

He didn't suggest that at all. He is saying it isn't optimized for the xbox360, nor is it as far along in development as the PC version. He didn't say anything about the bandwidth the xbox360 has.

 

[ihamoitc2005]

Bandwidth: PC vs Xbox360

He didn't suggest that at all. He is saying it isn't optimized for the xbox360, nor is it as far along in development as the PC version. He didn't say anything about the bandwidth the xbox360 has.

He did say his GPU became bandwidth limited at 1024x720 with 4xAA no? Does not his GPU have better bandwidth than Xbox360? If so, would not the Xbox360 become bandwidth limited as well at or below that resolution?

 

[The GameMaster]

He did say his GPU became bandwidth limited at 1024x720 with 4xAA no? Does not his GPU have better bandwidth than Xbox360? If so, would not the Xbox360 become bandwidth limited as well at or below that resolution?

No... and again for the reasons I stated above. Dave's article on XENOS sould help clear up some of that confusion...

http://www.beyond3d.com/articles/xenos/

I know on my Geforce 6800 the performance hit using 4x FSAA is as much as 20-30% at 1024x768, but on XENOS the performance hit using similar resolutions is only a few percent at 1280x720 (what performance loss is attributed to the tiles that are bined out to memory). PC GPUs become bandwidth limited a lot sooner than XENOS would...

As stated previously the majority of the most memory bandwidth intensive video functions was removed from the main memory and instead performed internally on XENOS's eDRAM.

 

[ihamoitc2005]

Why poor performance?

No... and again for the reasons I stated above. Dave's article on XENOS sould help clear up some of that confusion...

http://www.beyond3d.com/articles/xenos/

I know on my Geforce 6800 the performance hit using 4x FSAA is as much as 20-30% at 1024x768, but on XENOS the performance hit using similar resolutions is only a few percent at 1280x720 (what performance loss is attributed to the tiles that are bined out to memory). PC GPUs become bandwidth limited a lot sooner than XENOS would...

As stated previously the majority of the most memory bandwidth intensive video functions was removed from the main memory and instead performed internally on XENOS's eDRAM.

So youre saying the reason the Xbox360 version is less than half the performance of the 6800 version is not because of GPU but CPU? Why would they create new lower polygon models?

 

[Richard]

He did say his GPU became bandwidth limited at 1024x720 with 4xAA no?

No. All I said was the game became gpu bound at those resolutions. Whether that boundness is due to pixel fill-rate, or another GPU factor, I can't say.

 

[ihamoitc2005]

Msaa?

No. All I said was the game became gpu bound at those resolutions. Whether that boundness is due to pixel fill-rate, or another GPU factor, I can't say.

If its MSAA so the meaningful hit would be bandwidth no?

 

[The GameMaster]

So youre saying the reason the Xbox360 version is less than half the performance of the 6800 version is not because of GPU but CPU? Why would they create new lower polygon models?

A good question... unless it has to with something in regards to their method of collision detection. I am not familar enough with the Doom3 engine to answer why that is the case, but I am very sure it has very little to do with the GPU in this particular case. Again I am looking at the differences between the architecture the engine was made for (x86 OOE) to the architecture of XENON (PPC IOE), the other difference could be in the conversion of the OpenGL API that Doom3 was made on to the DirectX API that the XBox360 is based on.

Again I am not completely sure why they had to reduce the geometry as I know the Xbox360 is a lot more competent in pushing geometry than conventional PCs and this was demostrated in games like Project Gotham Racing 3 or Kameo where they have well over a million polygons per frame versus Doom3 that is pushing around 100k-200k polygons per frame at highest settings. I believe I said previously in another thread on another forum about this particular subject about the Xbox360's Quake4 that it is a bit unfair compairing a unfinished PORT of a PC game to a more finished PC version of the same game. I would much rather compare final products, but even still how PC games perform on both the XBox360 and the PS3 is not exactly the best way to compare either system's performance versus the PC.

In this particular issue... I blame the software instead of the hardware, or in this case the quality of the port.

 

[ihamoitc2005]

PGR3 and Kameo

A good question... unless it has to with something in regards to their method of collision detection.

Collision detection model need not be same as drawn model. I agree that its odd that they created new lower polygon models.

Again I am not completely sure why they had to reduce the geometry as I know the Xbox360 is a lot more competent in pushing geometry than conventional PCs and this was demostrated in games like Project Gotham Racing 3 or Kameo where they have well over a million polygons per frame versus Doom3 that is pushing around 100k-200k polygons per frame at highest settings.

Even if PGR3 and Kameo are 1M/frame (screenshots & videos not convincing), at 30fps, thats still only 30M/sec. Old consoles with 233mhz and 300mhz GPU = 10-20M polygons/sec.

For PC's, Doom3 was very low polygon most of the time. PC version of Far Cry was maximum of 500,000 polygons/frame, typical scene=200,000 polygons/frame. Whats typical frame-rate of 6800 running Far Cry in max detail with no AA?

Look at Gears of War, only 10,000 polygons for character model and not very impressive environments. More I look, more I think Xbox360 not so good at polygons.