Denis Dyack: On PS3 & Xbox 360

["Nerve-Damage"]

Forgive me if this was already posted.

Denis Dyack: On PS3 & Xbox 360

Asked about our favorite topic on the graphics power of the new consoles, Dyack said, "The 360 and the PS 3 are equal in power in my eyes. Maybe the PS 3 has more processing power. The 360 has more available memory. It's pretty much a net, net. The public perception of the PS 3 was that it was much more powerful. To developers, they look even."

1) Does he mean total usable memory after OS usage? Or is he directly referring to PS3 VRAM memory size?

2) Will this be PS3 major Achilles Hill?

There is potentially more power in the PS 3, he acknowledged, but it is harder to tap.

Dyack says that he believes that HDMI cable interfaces will make a difference in visual quality. That gives an edge to the PS 3. But he noted that authoring games in 720P resolution "looks nice." He adds, "It is questionable if there is a difference between 1080P and 720P. All of our games are likely to be 720P because of the faster refresh rates. There are all kinds of trade-offs. It takes a lot more RAM to do 1080P. You'll reserve RAM for the textures. 720P is just less pixels. There is definitely a huge difference from 720P and analog."

 

[Gholbine]

Memory consumption by the OS is something that could be reduced in future firmware updates, right? 96mb seems very excessive.

 

[Rangers]

Memory consumption by the OS is something that could be reduced in future firmware updates, right? 96mb seems very excessive.

Nobody will confirm that it is 96. In fact it's more likely to be 48 (OS memory is supposedly often doubled in Sony dev kits, so in retail units it might be half the reported 96). Still a bit more than X360's 32, but less important (if indeed it is 48).

So that leads me to believe in a sense devs seem to be treating the 360 like one big huge 512MB graphics card, while the PS3 gets treated like a 256 MB one (yes I know somebody will jump on me). Why this is, etc could be discussed.

And it's a bit funny because ms mentioned this as an advantage of the unified memory that there is not an arbitrary split. But I never thought it would actually matter, because they didn't really play it up. But devs keep mentioning it.

What's also interesting to me is repeatedly devs mention the PS3 having more peak power. I keep wondering if they are reffering to Cell vs XCpu or RSX vs Xenos, or both. I wish they would clear that up.

 

[Acert93]

Well, besides TH being bankrolled by MS... hint hint: PR!

That said, a 1080p framebuffer is going to be larger than a 720p one (with same level of MSAA of course). Also, since Xenos tiles from the eDRAM (where the multi-sampling takes place) the finished framebuffer in the UMA is smaller on Xenos than if this occured in the UMA itself. 720p w/ 4xMSAA is nearly 30MB, but on the 360 is like like a third or so of that. 20MB savings I guess, nothing to sneeze at, but not huge. If the OS on the PS3 is quite larger (uncomfirmed) I guess it could add up. Probably the biggest hurdle is on the PS3 you have a split memory configuration and unless you are exclusive or have middleware designed to deal with this, you either may not have the time and resources to effectively maximize the memory situation on the PS3 or, even worse, go the route of XDR for Cell and GDDR3 for RSX and call it a day.

But Sony has been doing a good job of getting exclusive titles to work toward the PS3 strengths, so I wouldn't worry too much about it. I am actually more concerned with MS's heavy reliance on middleware and the lack of effort put forth for things like tiling. Maybe Dennis would like to tackle that one... oh wait, he is using UE3 and won't be tiling at all

 

[RobertR1]

Before we begin the usual back n' forth, I think what you can take away from this is that both systems are very close. The skill of the development studio, their budget and the tools available to them will determine the outcome of a game.

 

[Jesus2006]

Well, besides TH being bankrolled by MS... hint hint: PR!

Yeah, I think this comes out of the split memory pools, so for him (no programmer!) it may be like "only 256MB on PS3"...

Before we begin the usual back n' forth, I think what you can take away from this is that both systems are very close. The skill of the development studio, their budget and the tools available to them will determine the outcome of a game.

But how do you emulate on Xenon when all SPEs are fully utilized on CELL? You can't do magic I think there will be a distinct difference between the two, mainly when it comes to first parties though (imo already visible in some FP launch titles)...

 

[LightHeaven]

What's also interesting to me is repeatedly devs mention the PS3 having more peak power. I keep wondering if they are reffering to Cell vs XCpu or RSX vs Xenos, or both. I wish they would clear that up.

They also always mention something like that "potential power" that Denis said... That makes me wonder wether they are comparing them by specs when drawing those conclusions. (and since aparently they can get more of 360 with more ease they say Ps3 is more dificult to tap, considering its supposed to be a more powerful machine)

 

[LunchBox]

I'm assuming that since the 360 is UMA there would be less copying between memory pools if done on the PS3?

 

[nonamer]

Has Dyack even touched a PS3 devkit yet?

And why would tiling save a whole lot of memory? Don't they still need a back buffer in main memory too to prevent flickering?

 

[assen]

Has Dyack even touched a PS3 devkit yet?

And why would tiling save a whole lot of memory? Don't they still need a back buffer in main memory too to prevent flickering?

Acert already explained it: if you're rendering at, say, 4xMSAA, you need 4x the back buffer. When tiling on Xenos, only the single tile that fits inside the eDRAM is 4x, and it is resolved ("downsampled") when transfered to main memory, so the main memory backbuffer is 4x smaller than it would be on a PC GPU or on RSX.

 

[pipo]

Nobody will confirm that it is 96. In fact it's more likely to be 48 (OS memory is supposedly often doubled in Sony dev kits, so in retail units it might be half the reported 96).

Not sure this is true, but I've heard the OS needs 64 MB main ram and 32 MB Vram. FWIW.

 

[StefanS]

This thread is getting closed. For some time now, we've been seeing an ever increasing onslaught of PR and consequently PR threads. Frankly, it's getting tiresome because everyone can tell how the thread will in fact end up.
So unless the interview actually contain valid and reasonable material, they're very likely to get locked.