Hyperthreading will it make a huge difference with DirectX 11 in games?

Nelly · 8 Sep 2009 at 20:17

As topic, does anyone have any links/source to know if it will?

Also will a card that uses DirectX 11 benefit older games using DirectX 9 or 10.1 i.e. quadcore + hyperthreading?

I guess its a case of "no one knows. . . " but you never know. :confused:

VonScar · 8 Sep 2009 at 20:25

I have heard that Windows 7 has better coding for multi CPU's, however I have not heard of many games that use Hyperthreading (Supreme Commander?).

The general rule of thumb with DX cards are, 1st gen DX card sucks, e.g DX 10 cards suck at DX 10, but excelled in DX9 performance.

I forsee a simlar situation with DX11 cards.

Buckster · 8 Sep 2009 at 20:26

not many games make full use of Quads .. so would be interesting to know this too

VonScar · 8 Sep 2009 at 20:35

Because DX11 had not been released, we can only surmise what it can do. Guess basically. Hyperthreading is unlikely to be utilised by many if any games for some time. Games developers try to produce games with maximum accessability, how many people buy I7's, also AMD does not have their own version.

I have read an article on DX 11, but I think that no true evidence exists, all we will get is a DX11 card from 10th September which will run DX 10 games for some time.

Cheers

Von

Lightnix · 8 Sep 2009 at 20:38

One thing that DirectX 11 is supposed to do is to split the software-end of the DirectX workload (remembering that DirectX isn't just about graphics, it also does input handling and more) up into threads in a more granular fashion. That should give a speed boost on multi-core CPUs, just by having developers implement DX11 (the work has already been done by Microsoft in that regard).

Rroff · 8 Sep 2009 at 21:09

I think generally it will make things a little more smoother and maybe there will be some shaders or physics effects that have a more complex version for systems with lots of threads... but I don't think there will be a dramatic performance shift for awhile.

Also with games, specially mmos, where you enter a new section and your fps drops for 10-20 seconds while it loads in new stuff, maybe a couple of pauses, on machines with lots of threads you might see a lot shorter period of lower performance or maybe even no drop out at all... but once loading is done you'd prolly get similiar performance.

Big.Wayne · 9 Sep 2009 at 02:56

Nelly said:
Hyperthreading will it make a huge difference with DirectX 11 in games?

Is there any difference between a logical core and a physical core? :confused:

I would have thought if a game responds well to multiple cores than it makes no difference if its logical or physical?

So to answer your question, if DirectX 11 benefits from multi-core it should benefit from HT! :cool:

Nelly · 9 Sep 2009 at 03:49

Big.Wayne said:
So to answer your question, if DirectX 11 benefits from multi-core it should benefit from HT!

Thats the thing though is their any limitation on how many DX11 will take advantage of i.e. 4 cores? 4 cores + 4 threads? eventually 6 cores etc.

topbanana · 9 Sep 2009 at 07:41

DirectX 11 is a lot more multithreaded than 10. For the first time the rendering will take place using multiple threads when appropriate. Games themselves are also beginning to take more advantage of multiple cores.

EvilOne · 9 Sep 2009 at 08:45

Big.Wayne said:
Is there any difference between a logical core and a physical core?

HT logical core's run at around 20% of the speed of a normal physical core. Not as good as real core's but it all adds up for free performance, especerly on quad core's.

derkaderka · 9 Sep 2009 at 08:58

I tried some things out with Arma2 ( I know its not dx 11 )
The Arma2 is multi core aware and uses multiple threads for different jobs within
the game engine.
I did some tests on my i7 system to see what effects HT ON or OFF would make
With HT on the 3d mark was higher 5-10% on average

When using HT on in arma2 the framerate was worse , my only guess why this is
You only have 4 "real" cores so if your trying to run 2 threads on 1 the physical
core the CPU spends loads of time doing context switches between threads
wasting a lot of CPU time doing this.

mmj_uk · 9 Sep 2009 at 13:07

If games utilise multicore heavily then yes the Hyperthreading will help, most current multithreaded games like Arma 2 use 25-50% of each of the four cores so it doesn't really matter if you have a 2.5ghz quad or a 4ghz quad with HT only difference will be your cpu utilization!

derkaderka · 9 Sep 2009 at 13:13

Yeah with Arma2 with HT off I get about 50-70% CPU utilisation
With HT on it about half of that , with worse actual framerates

Rroff · 9 Sep 2009 at 16:22

HT can be quite varied in performance... i.e. for folding. SETI. etc/ you can often increase your work load by over 50% - in some games you get closer to the performance of proper extra cores and in other games as people mention above you can end up seeing worse performance.

When COD2 was patched for multi threading - I got an automatic 50% boost in performance on the old P4 (800FSB + HT) - likewise with ETQW HT units gave around 30% increase in performance.

Tute · 9 Sep 2009 at 16:26

Does a game need specific patching for HT or will it help anything that's multi-threaded?

Broken Hope · 9 Sep 2009 at 16:26

Big.Wayne said:
Is there any difference between a logical core and a physical core?

I would have thought if a game responds well to multiple cores than it makes no difference if its logical or physical?

So to answer your question, if DirectX 11 benefits from multi-core it should benefit from HT!

Hyperthreading basically makes use of unused parts of a CPU core, so yes there is a difference between a logical and physical core. Having said that if a game is multithreaded then yes hyperthreading should increase performance, but not as much as if it was extra physical cores.

reflux · 9 Sep 2009 at 16:29

Just about all new titles use quad cores to some extent, so this is good news - the more the merrier.

mmj_uk · 9 Sep 2009 at 16:37

Tute said:
Does a game need specific patching for HT or will it help anything that's multi-threaded?

No it's OS controlled the game just needs to support up to 8 threads.

Some games (like WoW) might try to override the OS though and you can get a situation where a game is using 1 physical and 1 logical core (effectively 1 processor) instead of 2 physical processors which could affect performance.

It's generally better if game developers to just let the OS handle it.

derkaderka · 9 Sep 2009 at 17:48

Broken Hope said:
Hyperthreading basically makes use of unused parts of a CPU core, so yes there is a difference between a logical and physical core. Having said that if a game is multithreaded then yes hyperthreading should increase performance, but not as much as if it was extra physical cores.

Not exactly true , there are only 4 real physical cores
You just have an extra set of additional registers which can be switched between the processing part of the chip.

Big.Wayne · 9 Sep 2009 at 17:57

Tute said:
Does a game need specific patching for HT or will it help anything that's multi-threaded?

mmj_uk said:
No it's OS controlled the game just needs to support up to 8 threads.

That's what I believe to be correct, the game asks the O/S for resources and the O/S gives it cores. AFAIK the game just sees a core and can't tell the difference between Physical and Logical.

The performance difference may be different depending whether a Physical and Logical core is used but apart from that it should all be the same! :cool: