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Nec_V20
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Getting something for nothing - yes that does exist

Mon Jun 10, 2013 8:02 pm

So you think you cannot get something for nothing? Let me change your mind.

OK here's the deal, you have overclocked your processor and the game you are running doesn't really get the performance boost you were hoping for.

Here is a bit of really OLD knowledge which those of us who used to work with SMP (Symmetric MultiProcessing) machines knew but it seems to have been forgotten since SMP machines have become single die "cores".

With this simple little trick you will - depending on the game and the processor - get a hell of a lot more performance (even without overclocking) and it may even cure a games propensity to crash to desktop (CTD) or BSOD the system.

Since Windows NT one has had the ability to not only adjust the priority of a process but with multi processor machines one could also set the affinity.

Getting to the point you first of all have to turn off hyperthreading in the BIOS

If you open the Task Manager and you right click on a process you will see the option "Set Affinity". What this does is it fixes the process to run off one of the cores in your CPU, and stay there.

Now you could do this manually but the pain is that when you reboot all the settings are gone. So there is a nice utility where you can store profiles and load them to automate this process. The utility can be found here:

http://www.koma-code.de/?option=com_content&task=view&id=88&Itemid=93

You are thinking to yourself, "Why the hell should I do this?"

The reason is that Windows left to its own devices will mess you and your game playing session around. The main acceleration to your processing power comes from your L2 Cache - a bit of super fast memory between your processor and your RAM.

Now what happens is that you have your game running quite happily on one of the cores of your CPU but Windows decides to swap the game over to another core which it deems to be underutilised. This will of course wipe the L2 Cache and it will have to be filled again from the incredibly slower RAM.

Also Windows works on the basis of pre-emptive multitasking, which means that processes (your game for instance) get a certain time slice on any one of the cores where it is running and then it is another processes turn - again this mucks about with your game and the L2 Cache.

So what you do is boot up your system and when it is up and running, start CPU-Control and assign all of the running processes to CPU 0. Now some games take well to multi processors and some games not so much. You will have to do a bit of research on the game engine to determine that.

If you have found that the game can only run on one processor then load the game and allocate it to one of the remaining cores. If the game can use multiple processors then simply assign the game to the other three cores (on a quad core CPU).

Assigning a game that really only runs on one core to three cores is counterproductive and you will not get the acceleration you were hoping for, so you have to do your research on the game engine.

It is not unusual to find that games which were unplayable all of a sudden feel very comfortable on your machine if your computer has a weaker CPU.

It is more of a "go faster stripe" than any overclocking will ever give you with regard to weaker CPUs, that's for sure.

I have looked around and from what I have been able to garner those games which do take advantage of more than one core will only use two cores maximum.

Thus allocating games to three cores as I mentioned above when they can only use two cores maximum will actually negate the performance gain due to core swapping by Windows.

Probably the best bet is to just allocate the game to one core, see what kind of performance you get and then allocate it to two cores and see if the performance increases.
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Yeats
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Re: Getting something for nothing - yes that does exist

Mon Jun 10, 2013 8:34 pm

 
Nec_V20
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Re: Getting something for nothing - yes that does exist

Mon Jun 10, 2013 8:40 pm

Yeats wrote:
http://www.youtube.com/watch?v=lAD6Obi7Cag


When I originally thought of the title of the thread that was the song that was going through my head.

Especially with regard to "We got to move these refrigerators, we got to move these colour TV's" :lol:
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Yeats
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Re: Getting something for nothing - yes that does exist

Mon Jun 10, 2013 9:05 pm

I'm going to try this with Crysis 3, see how it works. In my case, there's definitely some CPU limitations going on: when I replaced my X6 1090t @ 4.2ghz with an FX-8350 @ 5ghz, the avg FPS jumped from 41 to 47. I'll have to see if I can disable a module (2 "cores") in the BIOS and then compare with setting the Affinity.
 
LostCat
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Re: Getting something for nothing - yes that does exist

Mon Jun 10, 2013 9:13 pm

Nec_V20 wrote:
I have looked around and from what I have been able to garner those games which do take advantage of more than one core will only use two cores maximum.

It really depends which games.

You can see older games don't do a lot with more than two cores http://www.overclock.net/t/659536/conta ... ng-results

On those that do, note the minimum FPS changes a LOT more than the average or max FPS...and those game choices are fairly old.

Dual core doesn't fare so well here - http://www.broadbandreports.com/forum/r ... Multi-Core

Anyway unless you're using Windows XP or really crappy software/malware is taking a chunk out of core 1 I wouldn't see the point to messing with this.
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Yeats
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Re: Getting something for nothing - yes that does exist

Mon Jun 10, 2013 9:43 pm

Well, FWIW, I get the same FPS in Crysis 3 with 6 or 8 cores, then with just 4 the game becomes choppy. Maybe if I can dig up a CPU-hungry older game I'll be able to see an improvement.
 
Nec_V20
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Re: Getting something for nothing - yes that does exist

Tue Jun 11, 2013 2:21 am

Yeats wrote:
Well, FWIW, I get the same FPS in Crysis 3 with 6 or 8 cores, then with just 4 the game becomes choppy. Maybe if I can dig up a CPU-hungry older game I'll be able to see an improvement.


I have been using this over the past few years on Laptops or Notebooks.

I'm not into Crysis or games like that. I like things like X3, C&C, Warhammer 40K, AoE, Diablo, Starcraft etc.

The very first thing you have to do before trying this out is to disable Hyperthreading in the BIOS

Then you load CPU Control and assign all running processes to CPU0 (Core 0)

Then load the game, tab out into CPU Control and assign the game engine to one of the other cores. Play it and see what it plays like.

You will have next to no affect if you already have a pretty powerful CPU and the game mainly utilises the GPU.

What this does is prevent the drops and the hangs in a game when the L2 gets dirtied and the game engine has to wait for data to be reloaded from RAM.

As an example, my neighbour wanted to see what games he could run on his laptop. I installed Command&Conquer (I think it was C&C3). When it loaded it took forever for the mouse to react and then when I had chosen the troops they did nothing for a second or so and then there was some movement and then nothing again. I then assigned the game to run off one core on its own and the game was playable.

It's one of those "YMMV" kind of things.
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