Multi Thread Games on Single Core

magick

just wondering how will games that are designed for multi core cpus operate on single core cpus? will their be a noticable effect?

SouperComputer

depends on the game and what hardware you are comparing.

Quake has been multithreaded since the begininng but has been running on single core\cpu computers for many years.

zilog_jones

Yeah what he said. There's multithreading, and there's symmetric multiprocessing - it's the latter that won't work too well on single core machines.

quozl

SouperComputer wrote:

depends on the game and what hardware you are comparing.

Quake has been multithreaded since the begininng but has been running on single core\cpu computers for many years.

I think Q3 was the first one of them that was multi-threaded and that was barely multi-threaded. There was the main thread and a second audio thread, so a second cpu didn't really make that much of a difference.

Magick I wouldn't worry about multi-threaded games and single core cpu's for a generation or two yet. The vast majority of commercial games are still single threaded, or token multi-threaded like Q3 and are likely to fair better on a single really fast core than on 2 significantly slower ones.

Besides multi-threaded programs run fine (though not as well) on single core machines, have you ever used a divx or other mpeg encoder?

Khannie

quozl wrote:

Besides multi-threaded programs run fine (though not as well) on single core machines

This is the key point. The OS schedules CPU time for each thread in a single CPU setup. It has an overhead, but it's not that noticeable. Intel chips fare better than AMD ones in this scenario though.

astrofool

I think Quake4 was getting a 10-20% boost from dual core setups.

It's funny now how people talk about Single core as if they didn't handle multithreading at all In terms of smoothness, a dual core cpu with multiple single threaded apps open will be very responsive, as less switches between threads for the OS are needed (which typically only take up 1-2% of CPU anyway). It'll be interesting as apps become multithreaded that smoothness of the PC may decrease as a result as you have an app using 100% of both CPU's.

DemonOfTheFall

astrofool wrote:

I think Quake4 was getting a 10-20% boost from dual core setups.

It's funny now how people talk about Single core as if they didn't handle multithreading at all In terms of smoothness, a dual core cpu with multiple single threaded apps open will be very responsive, as less switches between threads for the OS are needed (which typically only take up 1-2% of CPU anyway). It'll be interesting as apps become multithreaded that smoothness of the PC may decrease as a result as you have an app using 100% of both CPU's.

With a 7600GT or a 6800GT I've found the gains from dual core to be more like 50-60% with Quake 4, it's like a different game. That said I haven't seen any benefits as such with any other games, other than the loss of incredible slowness if any other app pops up.

TomCo

DemonOfTheFall wrote:

other than the loss of incredible slowness if any other app pops up.

Worth it for that alone, anyone else notice how GoogleTalk kills steam games?