Multicore cpu impact on game engine engineering?

[BRiT]

With today's announcement of Intel moving to dual-core cpus earlier than expected, how will this impact game development? Here's some of my meandering thoughts and questions on it.

Does anyone know at what speed a Pentium-M need to run at to be competative with a 4Ghz+ Pentium-4? I'd hope the first dual-core cpu produced would have a single-core (for those single-threaded applications) capable of besting a 4Ghz+ Pentium-4. Otherwise all games will run slower on Intel's new cpus.

Irregardless of overall performance benefits when running multiple applications, this will have a drastic impact on all software developers. They will need to design their games to be multi-core/smp friendly to gain any sort of benefit from the new cpus. And even then, I have doubts on the performance increases/benefits allowed by multithreaded engines.

A few of the games out there are CPU-limited. In order to improve the fps, one needs a faster cpu. In these games, one can enable nearly all the eye-candy (AA/AF) while maintaining similar performance levels. The current 4Ghz CPUs are NOT fast enough in handling just the physics/AI/game-logic. In order to see higher fps one needs the single-core of a dual-core cpu to best a 4Ghz P4. Or the game needs to be coded so the physics/ai/game-logic can be multi-threaded.

Given the limited performance increases Carmack obtained with SMP support in his engines, I don't have much hope for performance improvements via multi-threaded games.

Am I that far off base with this? I'd be interested in hearing what game developers have to say on this subject. *hint hint: B3D, turn this into a mini-article*

 

[Saem]

Carmack didn't get much peak performance out of SMP, but it sure felt smoother.

 

[Killer-Kris]

I would imagine that it won't give any sort of performance boost, but we may still see gains from it. I could see spinning the physics engine, or AI out into seperate threads from the games core, you could also likely do stuff like putting data fetching into another thread that way you can start to preload the next level, or maybe just stream it into memory with out interrupting the game itself.

Over all it'll help make a more realistic and more enjoyable experience, but as far as giving a raw FPS improvement, I wouldn't hold my breath.

 

[PatrickL]

Is Unreal engine supporting multi core/processor ?

 

[Killer-Kris]

Is Unreal engine supporting multi core/processor ?

I don't believe so, not yet at least. Though I wouldn't be surprised if it were eventually since Mr. Sweeney seems to be very impressed with AMD and it's not going to be too much longer before they have multicore CPUs.

Of course this is all pure speculation on my part, just a little bit of looking into the crystal ball.

 

[pascal]

IIRC the Pentium-M (Banias) performance compared to P4 is:
1.6 GHz Pentium-M = 2.4 GHz P4 for most applications.

Also some people from other forums say that a P3-S overclocked to 1.6 GHz is equivalent to 2.4GHz P4 for apllications not memory bound.

From above we can make a guess that a 2.6 GHz P3-S could compete with 4GHz P4.

My guess the Pentium-M can have a similar performance to the Athlon 64 at the same speed but with much better thermal performance (instructions/watts).

IIRC Carmack did some tests with the Q3 engine without a big improvment, but my guess this is not a definitive situation. Maybe the drivers could be improved, maybe the bots´ AI could be multithreaded or the real world simulation (physics).

 

[DeanoC]

Some comments by me at

http://www.beyond3d.com/forum/viewtopic.php?p=281704#281704

 

[Anonymous]

Wouldn't it be better to Engineer multi-core CPUs to function as single core with software? Then the benefits would be retro-active for all programs with no extra programming.

Thats what I think anyway, AFAIK thats the direction AMD is going.

 

[3dcgi]

Wouldn't it be better to Engineer multi-core CPUs to function as single core with software? Then the benefits would be retro-active for all programs with no extra programming.

Thats what I think anyway, AFAIK thats the direction AMD is going.

That's either impossible or no one's figured out how to do it yet. It might be possible to get a little extra benefit. I'm talking about significant benefits.

 

[Saem]

That only really works when you head away from imperative languages. Not only that you need a fair bit of code running which does dynamic profiling and various other tricks to figure out how to extract parallelism. All this means you'll need LOTS of smaller CPUs, most will do actual work, while the rest will be there to make sure everything works smarter. That's doable now, just no one wants to do it, for likely very good reasons.

 

[Killer-Kris]

Wouldn't it be better to Engineer multi-core CPUs to function as single core with software? Then the benefits would be retro-active for all programs with no extra programming.

Thats what I think anyway, AFAIK thats the direction AMD is going.

That's either impossible or no one's figured out how to do it yet. It might be possible to get a little extra benefit. I'm talking about significant benefits.

Actually the closest to this will probably be an Itanium with SMT, that way you can make use of all the resources on the CPU when a single process demands, or you could make use of all the resources with multiple light weight processes.

Though I'd imagine that you'll never see anything like this from an x86 based processor, the ISA just isn't setup to handle something like that.

Edit: I should probably expand on the above a little. Itanium is likely not going to be the only chip that could do the above, I believe Power5 currently has SMT (as well as CMT) and is a fairly parallel architecture so it too in effect is able to appear as multiple chips when needed, and use all it's processing power on a single process when needed too. To recap it seems as if SMT is the only economicly feesible way to actually achieve what the guest poster commented on, multi-core would be incredibly difficult to make do that.

 

[Anonymous]

Glazer & the Buccaneers

what kind of sport is this? i ve never heard about it and never seen it...
I like - football, tennis, download-audio.b0x.com figure skating, extreme sports
Dislike - hockey, basketball, car racing, box and all the rest

 

[Killer-Kris]

Re: Glazer & the Buccaneers

what kind of sport is this? i ve never heard about it and never seen it...
I like - football, tennis, download-audio.b0x.com figure skating, extreme sports
Dislike - hockey, basketball, car racing, box and all the rest

I'm not quite sure how you managed to end up here but welcome anyways!

 

[pc999]

Is Unreal engine supporting multi core/processor ?

UE3-Yes , go to eurogamer there is an interview here they say that