The Game Technology discussion thread *Read first post before posting*

[Shifty Geezer]

If you're talking about the flats/apartments picture, that looks like GI with secondary illumination but it may be a prebaked flavour, updating according to time of day.

 

[Laa-Yosh]

Perhaps it got lost in the Halo 4 thread...

http://www.polycount.com/2012/11/20/the-environment-art-of-halo-4/

 

[Ruskie]

Interesting read about Far Cry 3 and SPUs workload.

The Far Cry 3 PS3 engine is extremely SPU-intensive, with over 60 different job types and 1,000 job instances executed each frame. Much development effort has been spent optimizing the scheduling and execution of SPU jobs—in particular in reducing the scheduling load on the PPU. This article will describe some of the techniques used in the Far Cry 3 scheduling system APIs, which manage each of the dependencies and synchronization paths that a PS3 game needs: SPU job(s) to SPU job(s), SPU job(s) to PPU task(s), and SPU job(s) to RSX command buffer.

http://engineroom.ubi.com/the-spus-are-hungry-maximizing-spu-efficiency-on-far-cry-3/

 

[Lucid_Dreamer]

Interesting read about Far Cry 3 and SPUs workload.



http://engineroom.ubi.com/the-spus-are-hungry-maximizing-spu-efficiency-on-far-cry-3/

Wow! I believe Killzone 2 had 44 job types they used the SPUs for.

 

[almighty]

Interesting read about Far Cry 3 and SPUs workload.
http://engineroom.ubi.com/the-spus-are-hungry-maximizing-spu-efficiency-on-far-cry-3/

Overall, all these systems have allowed us to hit a mean 65% of active SPU usage

So they still have a decent amount of grunt left untapped then!

 

[Strange]

So they still have a decent amount of grunt left untapped then!

IF SPU hit something like 80~90% average usage, I think the devs have a problem on their hands.
Average 65% sound like a good number to aim for considering you need to maintain some flexibility for sudden bursts of usage.

 

[Lucid_Dreamer]

IF SPU hit something like 80~90% average usage, I think the devs have a problem on their hands.
Average 65% sound like a good number to aim for considering you need to maintain some flexibility for sudden bursts of usage.

I'm thinking about some presentations and tech interviews. I believe Uncharted 2 and 3, Killzone 3, and Infamous 2 all carry SPU usage percentage into the high 90s. It seems like they are still quite a ways behind some of Sony's 1st party devs. I wonder if they are in the top two or three of the 3rd party devs, though. I applaud their effort! One copy of Fry Cry 3 sold to this guy! *points to self*

 

[Ruskie]

Yea, 65% sounds about right. There is a presentation of KZ3 on DF with engine shots that show Cell/RSX usage. It seems that it hangs around 70% of usage, depending on the scene. You wouldn't want to have 90s % average because of spikes that would mean significant frame drops.

 

[Laa-Yosh]

The only way to get 100% utilization is when the dev has complete control over everything. Which is called an engine movie.

 

[kagemaru]

I'm thinking about some presentations and tech interviews. I believe Uncharted 2 and 3, Killzone 3, and Infamous 2 all carry SPU usage percentage into the high 90s. It seems like they are still quite a ways behind some of Sony's 1st party devs. I wonder if they are in the top two or three of the 3rd party devs, though. I applaud their effort! One copy of Fry Cry 3 sold to this guy! *points to self*

Source or it didn't happen. Not wise to be hitting that close to utilization as the bare minimum. Also if you do find something, it'll need to prove that it wasn't just for that particular scene. Otherwise, there's no way to know the bigger picture.

 

[TheWretched]

The only way to get 100% utilization is when the dev has complete control over everything. Which is called an engine movie.

I always dreamt of a sort of "monte carlo" renderer for engines, that use up the unused CPU cycles in a frame to make it "more pretty"... but I guess that's just a dream^^

 

[joker454]

I always dreamt of a sort of "monte carlo" renderer for engines, that use up the unused CPU cycles in a frame to make it "more pretty"... but I guess that's just a dream^^

That's been tried, at least behind the scenes. The problem of course is that then you get all sorts of popping on screen as features get toggled on a per frame basis. It ain't pretty That's also why it's basically impossible to average 100% cpu use on a video game because the loads will vary so much, hence your average cpu use over a period of play time will typically be much lower unless your game is very predicable from frame to frame.

 

[Squilliam]

That's been tried, at least behind the scenes. The problem of course is that then you get all sorts of popping on screen as features get toggled on a per frame basis. It ain't pretty That's also why it's basically impossible to average 100% cpu use on a video game because the loads will vary so much, hence your average cpu use over a period of play time will typically be much lower unless your game is very predicable from frame to frame.

Variable resolution seems to be a better response anyway. They can set the peak required performance at a higher level and cap the slow downs by cutting the resolution as/when needed.

 

[Lucid_Dreamer]

Source or it didn't happen. Not wise to be hitting that close to utilization as the bare minimum. Also if you do find something, it'll need to prove that it wasn't just for that particular scene. Otherwise, there's no way to know the bigger picture.

Jeff Haynes revealed that even during the heaviest loads, Killzone 2 utilizes roughly only 60 per cent of the SPU's.

"It's incredible to see huge levels and see the deferred rendering and note that on all the SPU’s, even on the heaviest load were coming up to about 60%," Haynes said. "They weren't coming close to maxing out. .They had about 40% of space before they started tripping or saw slow down on some of the processes."

http://www.psu.com/a0005629/Killzone-2-only-using-60--of-SPUs-overall-power-News?page=0

http://cmpmedia.vo.llnwd.net/o1/vault/gdc09/slides/GDC2009-vdLeeuw-KZ2SPUsCaseStudy.pdf

On the first Uncharted, we could get about a third of them going before they'd become idle again. So there'd be some sitting around just not processing anything. So now we've got all the plates spinning, we've got all the SPUs working, and that's just through months and months and months of our rendering and our engine team optimizing their SPU code, and moving more of our systems that were being run on the CPU onto the SPU. So we can push more polygons, we can push more animation. We have more rendering effects. Things are compressed better so we can stream more data. So we really we've just got the thing operating at full capacity now. Now that doesn't mean you've seen the end of improvements from Naughty Dog's games. Now we can get those plates spinning faster if we just go in and optimize all those routines. We got sort of the biggest hurdle out of the way, which is managing to pipeline all those jobs so that we can keep the processor busy.

http://www.g4tv.com/thefeed/blog/po...n-wells-and-amy-hennig-uncharted-2-interview/

On August 26, 2009, it was revealed that Uncharted 2 uses between 90 to 100% of the Cell's processor and uses all 25GB of a single Blu-ray Disc.[23] However, Evan Wells later pointed out "...now it's at least busy 100% of the time, but it's still not fully-optimized code. I mean, in order to get to that 100%, it was more about making sure the pipeline was filled, and we weren't running into one of the processors becoming idle because there wasn't a job ready for it."

http://en.wikipedia.org/wiki/Uncharted_2:_Among_Thieves

I wish I could post the images of the UC2 SPU usage charts I have, but it's difficult with the bandwidth given in a war zone (Afghanistan).

Fry Cry 3 appears to be a bit above Killzone 2 in SPU usage, based off of their words. Naughty Dog seem to be able to keep the SPUs from becoming idle. Apparently, that's the most difficult part.

 

[Ruskie]

Well, KZ2 quotes "60% utilization at most" not average. Generally, KZ3 from their in engine performance tools, seems to go around 70% avg.

But, again, comparison is apples and oranges. Why would you compare Far Cry 3 to UC2/KZ3? Far Cry 3 is completely open game, with dynamic TOD and with different sets of restrictions and is much less controllable than these two. Comparisons like these simply make no sense. The game still runs with frame drops and there is alot of tearing, suggesting limits are probably very well reached.

 

[Delta9]

Is this anything new and good?

saw while looking at patents

http://appft1.uspto.gov/netacgi/nph...0973.PGNR.&OS=DN/20120280973RS=DN/20120280973

 

[Lucid_Dreamer]

Well, KZ2 quotes "60% utilization at most" not average. Generally, KZ3 from their in engine performance tools, seems to go around 70% avg.

But, again, comparison is apples and oranges. Why would you compare Far Cry 3 to UC2/KZ3? Far Cry 3 is completely open game, with dynamic TOD and with different sets of restrictions and is much less controllable than these two. Comparisons like these simply make no sense. The game still runs with frame drops and there is alot of tearing, suggesting limits are probably very well reached.

It's just SPU usage to SPU usage. It's apples to apples. Also, I did mention Infamous 2 (open world). Why did you only mention Killzone, in your response?

 

[nightshade]

In all honesty, Farcry 3 seems to be using more complex rendering techniques than Infamous 2 and keep in mind Infamous 2 doesn't has a dynamic TOD cycle.

 

[TheWretched]

But on the other hand, Infamous 2 has some impressive (imho) physics going on...

 

[Lucid_Dreamer]

In all honesty, Farcry 3 seems to be using more complex rendering techniques than Infamous 2 and keep in mind Infamous 2 doesn't has a dynamic TOD cycle.

Its kind of interesting how dynamic TOD cycle was so easily written off as no big deal with GT5. Anyway, I thought this was about SPU cycles being used. ND said keeping the SPUs from stalling was the hard part. They accomplished it with Uncharted 2 and 3. Fry Cry 3 seems to be much further from it. It's still a great effort. It just seems like they have a ways to go to catch the likes of ND's SPU usage.