Disabling some cores to get more overclock

[chiliwili69]

I just wanted to share one thing we tested at work with one PC, where we needed to squeeze as much as possible in single-thread performance.

 

The PC specs are:

Mobo: ATX Z390 ASUS ROG Maximus XI Apex 
CPU: i9 9900K 
CPU cooler: Noctua NH-D15S
RAM: 32 GB DDR4 a 3600 MHz. Kingston HyperX Predator 

 

The PC was provided by a company who provide mounted PCs with overclock and warranty.

The initial OC was 5.0 GHz for all 8 cores with 1.26V with no AVX offset and hyperthreading ON.

 

We then explained to them that our application run just in only one core, so we might not need HT or many cores to run.

 

Then we tested to disable HT and also disable 6 and 4 cores and increase the freq:

 

2 cores enabled: 5.3 GHz (both)

4 cores enabled: 5.2 GHz (all 4)

 

All this with 1.26V and temps around 60 celsius and stress CPU app running.

 

So, if you only use your PC for IL-2 (single-thread dependent) you can squeeze a little bit more your CPU by disabling  some cores and get some more stable OC. In the case of IL-2 I think you should always maintain at least 4 cores active, since we know IL-2 VR has at least 4 threads, being one of them the heavy one. You will also save some dollars in your electricity bill.

 

You can also use the i3-9350K (4 cores) or i5-9600K (6 cores) to do that, but those have less L3 cache. (we don´t really know the influence of L3 cache in IL-2 VR)

 

 

[HogMenTheHog107]

Thanks!  I have a new i9 9900K and would not have thought of this, I'll have to try it out.

 

 

[BroGrimm1tkcamp]

should we still turn hyper threading off for VR? I am running a 8086K with  Pimax 5k+

VR

Also wondering about the AVX offset,  on or off?

 

Edited October 7, 2019 by BroGrimm1tkcamp

[dburne]

No need for hyper threading in games, I have never used it.

I myself run with no AVX offset.

 

In observing my CPU core usage while gaming, it would seem to me it can vary which cores it uses on my 9900k during the game , but I really do not know this to be factual.

[chiliwili69]

22 hours ago, BroGrimm1tkcamp said:

should we still turn hyper threading off for VR? I am running a 8086K with  Pimax 5k+

VR

Also wondering about the AVX offset,  on or off?

 

With the 8086K you have 8 physical cores, 6 physical cores and if you activate Hyperthreading then every physical core creates a "virtual" core so you have 16 12 cores in total (6 physical + 6 virtual). Apparently this could create a very little bit more power , so more heat, so more temp, so less stable, so very little bit less OC.

 

But for IL-2 VR you will not need more than 4 cores, so there is no real reason to activate Hyperthreading.

 

Regarding AVX instructions, IL-2 make use of AVX instructions, so it will use the offset if you activate it. And those Ghz will be discounted to you clock speed.

So, best is to put offset to zero.

 

Edited October 8, 2019 by chiliwili69

[dburne]

With Hyperthreading on they are considered threads, so an 8 core processor with HT = 16 threads.

4 core processor with HT - 8 threads.

 

Main benefit to HT is doing things like video processing, etc - heavy lifting/computation.

Gaming no real benefit.

Edited October 7, 2019 by dburne

[ironk79]

16 hours ago, chiliwili69 said:

 

With the 8086K you have 8 physical cores

 

 8086k has "only" 6 cores

[BroGrimm1tkcamp]

Thanks Guys I have been wondering this for a time now. I'll stick to my current setting. Although I have never looked at the AVX and don't know what the default is, I may have to change this one.

[Alonzo]

On 10/7/2019 at 9:39 AM, chiliwili69 said:

So, if you only use your PC for IL-2 (single-thread dependent) you can squeeze a little bit more your CPU by disabling  some cores and get some more stable OC. In the case of IL-2 I think you should always maintain at least 4 cores active, since we know IL-2 VR has at least 4 threads, being one of them the heavy one. You will also save some dollars in your electricity bill.

 

Last time I was looking at my performance figures, on Kuban map with some AI flying around, my CPU frame time was about 5-6ms on my 8086K @ 4.9ghz. I think the game is better multicore optimized this patch. Do we know if it still needs the high core clocks?

[chiliwili69]

3 hours ago, Alonzo said:

I think the game is better multicore optimized this patch. Do we know if it still needs the high core clocks?

 

We knew from the past that there were only 4-5 threads in IL-2 VR:

https://forum.il2sturmovik.com/topic/29322-measuring-rig-performance-common-baseline-for-il-2-v3010/?do=findComment&comment=499246

 

The red thread was the heavy one which bottleneck the whole thing.

You can run now Perfmon utility to see if load is more distributed than in the past.

 

Regarding the core clock, this is a good question. In the past we saw clearly the influence but I don´t know now.

You could just create a flight record and run it in Monitor or VR at different clock frequencies and record the fps and compare.

I did that in the past, look here:

 

[Jaws2002]

On 10/7/2019 at 4:35 PM, dburne said:

With Hyperthreading on they are considered threads, so an 8 core processor with HT = 16 threads.

4 core processor with HT - 8 threads.

 

Main benefit to HT is doing things like video processing, etc - heavy lifting/computation.

Gaming no real benefit.

 I look at this from a different angle. Game developers do hardware surveys when they develop a game engine. Up until last year, four cores was standard for gaming. Very few cpus had more then four, so game developers made the engines to only take advantage of four cores. It doesn't mean that they can't update the engines to take advantage of more cores.  Developers just didn't think it will be needed.

Now things are changing extremely fast. 

There are affordable eight and even 12 core CPUs out there and the first 16 core mainstream CPU comes out next week. I'm not even talking about the multi threading monsters like Threadripper or the Intel's HEDT processors that are pushing things really fast. Heck,  Even the new consoles coming out next year, will have eight cores!

Right now,  even  Microsoft is actively upgrading windows to better take advantage of more cores and threads and is optimizing windows to hit the fastest cores with more work. Things are moving fast.

 

So i think the gaming industry should feel the pressure to upgrade their obsolete game engines to actually use the available computing power, sleeping on user's PCs.  

It's not true that games can't efficiently use more cores/threads. It was a calculated decision to stick with poor multicore optimization, but now, with things changing so rapidly, i think that's  simply lazy programming.

   

[Dakpilot]

Expensive programming 

 

Cheers, Dakpilot