Gaming on multicore CPUs

BAMBI · 30 Jun 2007 at 17:08

Are any games multithreaded yet? or do all dual cores simply use one core to run games?

Alex UK · 30 Jun 2007 at 17:27

Most new games take advantage of Dual Core these days.

Oliet_No1 · 30 Jun 2007 at 17:56

Doesnt Supreme Commander use 4 iirc?

sulli · 30 Jun 2007 at 18:00

Crysis will make use of muti cores when it comes out

t31os · 30 Jun 2007 at 18:14

sulli said:
Crysis will make use of muti cores when it comes out

That's the one i'm looking forward to most, going to upgrade when the price drops come into effect ready for this game....

snowdog · 30 Jun 2007 at 18:21

Supcom has support for upto 16 cores.
Most games have dual core patches now, modern games anyhow (fear, quake4, etc...).
New games seem to come with dual core support now too.

mattyrigby00 · 30 Jun 2007 at 23:05

even on games which arent for dual cores, say for example a 2.2ghz dual core will be better than a slightly higher single core because of all the random processes for services etc being split between the 2 cores

mentalist · 30 Jun 2007 at 23:25

Quake 4 and ET:QW use already

BAMBI · 1 Jul 2007 at 10:06

Thats good to know, took them a while to make the move though!

Raves · 2 Jul 2007 at 07:50

IMO the support for dual cores is pretty rudimentry atm. The mostly you get and another thread for physics or AI - but thats about it.

Heres a good summary that can be found here.

Because the synchronous function parallel model does not require special changes to engine components, and is really just an enhancement of a regular game loop, it is well suited for adding some amount of parallelism to an existing game engine. The model is not suited for future use because of it's weak scaling support and low amount of parallelism.

The asynchronous function parallel model can be recommended for new game engines because of the high amount of possible parallelism and the fact that existing components need only few changes. This model is a good choice for game engines aimed at the generation of multicore processors that have a relatively small number of cores. The only drawback is the need to tune thread running times to minimize the impact of worst case thread timings. More research is needed to know how this timing fluctuation actually affects game play.

The data parallel model is definitely something to think about for the future. It will be needed when the amount of processor cores increases beyond the number of tasks available for a function parallel model. For current use the increased scalability doesn't offer enough benefits compared to the trouble of coding custom components to support this type of data parallelism.

The current trend seems to be towards creating engine components that use some internal form of parallelization. While this allows engine developers to not worry about threading issues, it may leave large parts of the program sequential, which results in poor performance. The view presented in this article has been that whole game loops could be parallelized, not just some parts of them. The models presented here can be a good starting point for developing specialized game engine architectures.

We are currently seeing the type of programming described in paragraph one.

Vertigo · 2 Jul 2007 at 07:53

SupCom does use more than 2 cores but not efficiently. From what I understand, it uses extra cores for separate tasks which may not fully utilise the cores so you don't get very good scaling as the number of cores increase.

The situation may get better with future patches but I don't think quads are showing much of an advantage over duals in SC right now, especially when you consider duals usually clock better.

Cyber-Mav · 2 Jul 2007 at 11:28

Vertigo1 said:
SupCom does use more than 2 cores but not efficiently. From what I understand, it uses extra cores for separate tasks which may not fully utilise the cores so you don't get very good scaling as the number of cores increase.

The situation may get better with future patches but I don't think quads are showing much of an advantage over duals in SC right now, especially when you consider duals usually clock better.

http://enthusiast.hardocp.com/article.html?art=MTMwNiwsLGhlbnRodXNpYXN0

jaykay · 2 Jul 2007 at 12:00

Vertigo1 said:
SupCom does use more than 2 cores but not efficiently. From what I understand, it uses extra cores for separate tasks which may not fully utilise the cores so you don't get very good scaling as the number of cores increase.

The situation may get better with future patches but I don't think quads are showing much of an advantage over duals in SC right now, especially when you consider duals usually clock better.

Yer you are correct

BAMBI · 2 Jul 2007 at 12:16

Thanks for the links guys, I never went dual core because there wasnt enough of a performance advantage in games up till now.

Vertigo · 2 Jul 2007 at 15:35

Cyber-Mav said:
http://enthusiast.hardocp.com/article.html?art=MTMwNiwsLGhlbnRodXNpYXN0

Very interesting, the game obviously scales much better than I'd been led to believe.

When choosing between dual and quad core, however, a couple of other things do need to be considered.

Firstly there's the issue of being graphics limited. At higher resolutions, games will become far less dependent on processor speed. This was evident in the above test when SC was cranked up to 2560x1600, the quad core making less of a difference as the graphics system struggled to keep up.

Secondly, dual-cores generally clock higher than their quad core equivalents at a given price point so, when making a purchasing decision, you're rarely comparing apples-to-apples. Yes, a quad core will always be at least as fast as the equivalently clocked dual core but how would a 3Ghz dual compared to a 2.4Ghz quad (E6850 vs Q6600, which will be priced the same)? Even in games which do support quad cores, such as SC, the difference would be greatly reduced plus you'll have better performance in games which only support single or dual-cores. Yes a quad is more forward thinking and more games will support them but then by the time this happens you'll probably be in the market for an upgrade anyway.

I'm shifting from AMD at the end of this month and am currently going through the E6850 vs Q6600 quandry. Currently I'm thinking the former would be a better choice (even though I play a lot of SC) as I reckon it'll give me 80% of the performance of the Q6600 in SC and better performance in most other things.

Opinions?

Lanz · 2 Jul 2007 at 16:30

BAMBI said:
Thanks for the links guys, I never went dual core because there wasnt enough of a performance advantage in games up till now.

Well there still isnt any real benefit from dual cores, even in the games that are meant to support it. Unless you're running at 800x600 then most modern (dual core) games are GPU limited.

So right now, with every game, you certainly dont need dual core. Performance increases are minimal at beat.

mikeo · 2 Jul 2007 at 16:51

Interesting.

Have been trying to decide whether to move from my single core AMD 4000 to an Opteron 180 (available for slightly less than £100 if you shop around)... or to finally buy myself a decent 19in LCD monitor. I think the comments here have made my mind up. So the new monitor it is ... and do a total upgrade back end of this year / early 2008... now just to decide which one!

Kace · 4 Jul 2007 at 14:45

Games are starting to be optimized for dual cores, depending on the game and how it's optimized you might get upto a 75% speed increase with using two over one core. The more cores you have after that the performance increase drops off rapidly. That's why I think Quad Cores are a bit pointless for gamers at the moment.

Raves · 4 Jul 2007 at 16:23

Which game yields a 75% increase?

Lanz · 4 Jul 2007 at 16:26

None will... ever with dual/quad core, as it's all about GPU nowadays. You can run all of todays games on a 2Ghz Northwood P4 if you had a good enough graphics card.