CPUs and DCS CPU Usage

I currently have a 6 core 12 thread Intel Core i7-8700K. I’m considering upgrading to an 8 core 16 thread i9-9900K. If I went ahead and made that upgrade, would DCS make use of the extra cores/threads or does DCS not make much use of multithreading?

According to Afterburner, the CPU often appears to be at 80% overall usage, but I’ve also read things in these forums that suggest DCS makes little use of multithreading, so I’d appreciate any clarity you can provide. Thanks :thumbup:

DCS does not use multithreading and only actually uses 2 physical cores. A well overclocked 8700K is a good chip. Including the cost of the new motherboard and possibly RAM is a big expense for a relatively small bump in performance. If you use Adobe Premiere or Blender or some kind of productivity software it might be worth it, but for DCS probably not.

Do you have anything else on your wishlist like pedals or peripherals? New monitor of gaming TV perhaps? If you are serious about the hobby I always recommend buying stuff that is not subject to Moore's law first, then upgrade your rig. I have a sim chair and pedals that will probably never break and no temptation to upgrade them every year or two. A good chair, pedals, monitor, and HOTAS are good investments for the immersion you get.

DCS will use the cores. You just don't need anymore than 4 for DCS right now as far as I can see and some good ghz.

I can saturate a 1080to or 20880ti with the 7700

Tested dropping back a core to 3 using process lasso and DCS does not like it at all.

Quick test for the other thread about VR. Watch Hardware monitor.

No Hyper threading on. Only 4 cores

Jump to 0:35 then full screen

Whatever ED is doing it's working better from what I can see.

Quick test

Need to test with a large mission with plenty of AI and scripts to really test the single core I guess...

F-14 take off Nellis

Max Settings @1440p Stock GPU clock

Plus

MSAA x 4

SSAA x 2

30 fps

Min pre set Settings @1080p Stock GPU clock

130+ fps

Hey Dave,

DCS only uses 2 cores. The Windows hardware monitor can be deceptive. Windows 10 has a cool feature where it will hop between different cores faster than a human can perceive. This prevents one core from getting too hot to prevent throttling. Give your test another try with Afterburner set up as a real time on screen display showing utilization similar to how I have it set up on the screen shot I uploaded. No Track IR was running, just DCS, Afterburner, GeForce Experience Overly, and normal background processes.

As you can see in the OSD it shows all 16 logical cores of my physical 8 core chip. The alternating 0% are the logical hyperthread cores that aren't being used. And as you can see on Core 15 there is 98% utilization. That's the single core that DCS really uses. Core 13 is at 33%, this is the core that DCS uses for audio if I remember correctly. BIOS for Intel motherboards is usually set to use the fastest cores by default, but you may have to manually enable it depending on your vendor. Core 11 at 23% is most likely the core that Afterburner or Geforce Overlay is running on. But it might be vice versa for core 11 and 13, hard to say without assigning affinity in ProcessLasso.

The OSD doesn't show it but I'm actually running a 5.2 GHz overclock on 2 cores while the rest are @ 5.0 GHz and it's stable because it requires less voltage and puts out less heat than trying to OC all 8 cores to 5.2.

FYI: An Intel 7700K only has 4 cores so it would be impossible to test on your system if it uses more than 4. It is also likely that your GPU is bottlenecked by your 7700K. I used to have a Titan Xp paired with a 7700k in my last build. When I built my new rig I tested the Titan Xp with the Z390 chipset and a 9900k and got about a 10% performance bump in frames. Trying to determine bottlenecking from percentage utilization of your GPU isn't necessarily accurate. The CPU is sending the GPU the draw calls, but the GPU does the work for the resolution and AA settings you have. Dropping down to 3 cores most likely resulted in background processes and other programs like TrackIR having to share the 3 cores which would give poor performance. I play in VR now so I have the framerate limiter in Riva Tuner set to 90 FPS. My gaming monitor goes up to 165 Hz and would show higher GPU utilization at those framerates. The 2nd GPU is showing 12% as I don't have my DCS SLI profile enabled in Nvidia Profile Inspector so that reading is kind of a red herring. Also, when you take screenshots outside of full screen with multiple windows that can show a higher utilization as the computer is multitasking more applications.

P.S. What do you use to record in VR?

The more apps you have running aside from DCS, the more more cores do matter to keep it smooth. Tho I dont think you see a noticeable difference between a 8700k anda 9900k at same Ghz. Those extra 2 cores + HT will not matter imho.

A 8700k 6c/12t is plenty for DCS even if you use OBS and others simultaneously.

Save those bucks until it really makes a difference imho.

Hey Dave,

 

DCS only uses 2 cores. The Windows hardware monitor can be deceptive. Windows 10 has a cool feature where it will hop between different cores faster than a human can perceive. This prevents one core from getting too hot to prevent throttling. Give your test another try with Afterburner set up as a real time on screen display showing utilization similar to how I have it set up on the screen shot I uploaded. No Track IR was running, just DCS, Afterburner, GeForce Experience Overly, and normal background processes.

 

As you can see in the OSD it shows all 16 logical cores of my physical 8 core chip. The alternating 0% are the logical hyperthread cores that aren't being used. And as you can see on Core 15 there is 98% utilization. That's the single core that DCS really uses. Core 13 is at 33%, this is the core that DCS uses for audio if I remember correctly. BIOS for Intel motherboards is usually set to use the fastest cores by default, but you may have to manually enable it depending on your vendor. Core 11 at 23% is most likely the core that Afterburner or Geforce Overlay is running on. But it might be vice versa for core 11 and 13, hard to say without assigning affinity in ProcessLasso.

 

The OSD doesn't show it but I'm actually running a 5.2 GHz overclock on 2 cores while the rest are @ 5.0 GHz and it's stable because it requires less voltage and puts out less heat than trying to OC all 8 cores to 5.2.

 

FYI: An Intel 7700K only has 4 cores so it would be impossible to test on your system if it uses more than 4. It is also likely that your GPU is bottlenecked by your 7700K. I used to have a Titan Xp paired with a 7700k in my last build. When I built my new rig I tested the Titan Xp with the Z390 chipset and a 9900k and got about a 10% performance bump in frames. Trying to determine bottlenecking from percentage utilization of your GPU isn't necessarily accurate. The CPU is sending the GPU the draw calls, but the GPU does the work for the resolution and AA settings you have. Dropping down to 3 cores most likely resulted in background processes and other programs like TrackIR having to share the 3 cores which would give poor performance. I play in VR now so I have the framerate limiter in Riva Tuner set to 90 FPS. My gaming monitor goes up to 165 Hz and would show higher GPU utilization at those framerates. The 2nd GPU is showing 12% as I don't have my DCS SLI profile enabled in Nvidia Profile Inspector so that reading is kind of a red herring. Also, when you take screenshots outside of full screen with multiple windows that can show a higher utilization as the computer is multitasking more applications.

 

P.S. What do you use to record in VR?

I don't go that far into it with msi, don't need to as I'm locked all the time at 60 fps for track ir and can hold that max settings on one of the largest servers @1440p. I only use VR for messing about. Don't like keeping it on for to long. Case 1's are fun now and then.

I don't think the 7700 @4 x 5Ghz would be a bottle neck for DCS with the 1080ti, perhaps some other multi-core games yes or until DCS gets vulkan fully implemented and can use all the cores with a battle of 1000s of units.

The setup and cost is not need for me from where I stand. Also waiting for the next real step up in VR. Then I might build a new complete rig from the ground up.

This was also about the OP and 6 cores. Just showing what you can still do with 4

Edit

That was just a quick desktop screen record. I use action for full screen and vr https://mirillis.com/en/products/action.html

I must of misunderstood your post. When you wrote "DCS will use the cores" I interpreted your post as saying DCS will use all the 8 cores of a 9900K. My mistake. I wish it did though.

Afterburner is really handy. It only takes a few minutes to set up the OSD. Good for keeping track of temps in real time. You can set the OSD to a hot key. The frametime graph comes in handy if you think your eyes are playing tricks on you with microstutters. If the frametime graph (16.6ms @ 60 fps for TrackIR) is smooth your eyes will perceive the animation as smooth. And if you think you saw a hiccup or stutter but you are not sure, it will show as a dip in the graph. Good for trying out new settings.

I don't think we are seeing a Vulkun build anytime soon, although I hope I am wrong. There is a popular GA sim that is converting to Vulkun and it's taking a long time.

Thank you all for your help. Wish I could +rep you because I’m leaving this conversation knowing a little more than I used to. I was persuaded to stick with the 8700 but my old mobo got damaged on reinstallation, so I wound up with the 9900K, but I’m glad to have reasonable expectations now :)

too soon to replace the 8700K.

I was persuaded to stick with the 8700 but my old mobo got damaged on reinstallation, so I wound up with the 9900K, but I’m glad to have reasonable expectations now :)

:music_whistling:

Well, the 9900k is not a bad decision. I am not sure if you had the 8700 or 8700k. For the K version, you could have kept it and replaced the broken board only.

Anyway, now overclock that little beast up and beyond 5G :smilewink:

CPUs and DCS CPU Usage

DCS will use the cores.

this is correct.

DCS creates many, many threads and they are NOT hamstrung and NOT pinned to a small limited set of cpu cores, unless you do it yourself.

that rumor was thoroughly debunked years ago.

this is correct.

 

DCS creates many, many threads and they are NOT hamstrung and NOT pinned to a small limited set of cpu cores, unless you do it yourself.

 

that rumor was thoroughly debunked years ago.

I'm not sure where you are getting your information from but DCS does not use multithreading or more than 2 cores. I wish that weren't the case but we have to wait for the new engine that uses the Vulkan API.

If you are referring to Afterburner, that can be deceptive because Win 10 can switch between cores faster than a person or the polling software can perceive to keep the CPU cool. It's still just 2 cores though.

Every chip no matter how many cores will have a core that is faster. That's what Intel's turboboost is. With Turboboost enabled DCS's graphics thread will settle on that core. On my machine it's core 8 or logical thread 15 usually but can vary from processor to processor.

If you are still skeptical of this you need to check with Big Newy or Skatezilla and they will confirm this. And they've both stated multiple times that DCS only uses 2 cores. That's where I am getting this information from.

Edit: Here's the best thread I found with a quick search.

https://forums.eagle.ru/showthread.php?t=201530

Conclusion: DCS still only uses 2 cores at any given time and does not use multiple threads within the same core. Single threaded IPC is still the limiting factor for CPUs in DCS currently, i.e. you won't get higher FPS with more cores.

And here's Skatezilla's first post on the Test: Setting CPU Affinity thread (no pun intended :music_whistling:)

https://forums.eagle.ru/showpost.php?p=1959076&postcount=1

And to make it even more confusing:

https://www.intel.com/content/www/us/en/architecture-and-technology/turbo-boost/turbo-boost-technology.html

I'm not sure where you are getting your information from but DCS does not use multithreading or more than 2 cores. I wish that weren't the case but we have to wait for the new engine that uses the Vulkan API.

Yes, and its really easy to check that DCS is very high on one core only and the other mostly no usage.

My 9900KS shows a total of 8% load, but logical core 15 is 70-100%.

Earlier with an i7@4.7ghz GTX1080 the CPU was the limiting factor for my settings and increasing the CPU frequency made a big inprovement in FPS. Despite this, most of the cores showed low usage and only one core 70-100%.

I'm not sure where you are getting your information from but DCS does not use multithreading or more than 2 cores.

That's not 100% correct.

Heatblur planes use a different core for their radar. So that would be three cores when playing the F-14 and Viggen.

Maybe the current ED planes use that feature, too - I don't know.

I've upgraded from 8350k @ 5ghz (4 cores) to a 9700k @5ghz also (8 cores) and not any fps difference.

CPUs and DCS CPU Usage

not sure where you are getting your information from but DCS does not use multithreading or more than 2 cores.

to limit the number of cores, the computer user, or the exe process has to set the core affinity mask and limit the core usage.

we know that DCS does not do this itself (you can check for yourself by looking at the DCS cpu mask when it’s running).

i’m not suggesting it can’t be limited to only two cores, but it’s not programmed to do that out of the box. it’s something a user would have to do manually with a tool (like process lasso)

I've been running DCS for over a year on my 8700K and 1080Ti with 32gb or DDR4 3000mhz RAM and everything runs great on ultra and high with excellent 1440p/144hz settings and they have been improving the optimization...I agree with Pilotasso, it's too soon to replace the 8700K.

But in your situation, you could build someone a decent rig with a new MOBO. Good Luck!

That's not 100% correct.

Heatblur planes use a different core for their radar. So that would be three cores when playing the F-14 and Viggen.

Maybe the current ED planes use that feature, too - I don't know.

Oh wow, I didn't know that, thanks for sharing.

Oh boy, now I have another variable to test and benchmark LOL

I had settled on just using the TF-51 on the Caucasus map because it's free but I might run a few comparison's with Heatblur's modules. I own the Tomcat and the Viggen.

This is why I love these forums and flight simming and gaming in general. You can never stop learning how to get the peak performance out of your system, there's always something new to explore. I honestly spend more time building, tinkering, and testing than I do just gaming.

It's not unusual for me to start a new game, get the graphics and mods installed and tuned, and then get bored and start tuning a new game. :huh:

to limit the number of cores, the computer user, or the exe process has to set the core affinity mask and limit the core usage.

 

we know that DCS does not do this itself (you can check for yourself by looking at the DCS cpu mask when it’s running).

 

i’m not suggesting it can’t be limited to only two cores, but it’s not programmed to do that out of the box. it’s something a user would have to do manually with a tool (like process lasso)

Not necessarily,

I use ProcessLasso but I don't set core affinity with it or any Windows utility. And if you use ProcessLasso to turn HT on or off you won't see any difference in FPS. I maybe see a little smoother line in the frame time graph with HT off but we are talking fractions of millisecond. It's not noticeable with your eyes. This was under test conditions with no TrackIR, Tacview, recording, streaming, etc. I think Bit mentioned all the stuff going on that might be influenced by HT but that's just more variables to test.

I set a 2 core ratio overclock in Asus BIOS to 5.2 GHz for DCS. Trying to OC all 8 cores requires more voltage and puts out more heat and you won't see any benefit in DCS. You can OC 2 cores higher and still stay stable versus OCing all 8 cores. I have a custom loop and a good chip from Silicon Lottery that was rated at 5.0 on all cores so YMMV. I think I might be able to push it to 5.3 or 5.4 GHz on 2 cores and stay in a safe voltage but haven't tried yet. I can stay stable playing DCS on OCs that crash Cinebench and other stress tests, DCS does not use AVX so you can usually push it pretty high and still stay stable.

If Intel Turboboost is enabled in BIOS, as it usually is by default, it will put demanding programs and games on the best core without the user doing anything manually.

https://www.intel.com/content/www/us/en/architecture-and-technology/turbo-boost/turbo-boost-max-technology.html

This should be transparent to most users as it's usually enabled by default and you would have to manually turn it off in your BIOS which I do not recommend.

CPUs and DCS CPU Usage

i’m not taking about overclocking, i’m saying that if you or DCS does not set core affinity in a way to limit the number of cores that can be used, then the task scheduler in the windows operating system will schedule any “ready-to-run” thread onto any available cpu core it wants to use.

(i.e. it will not limit the “ready” threads to specific cores)

thats the whole point of the core “affinity mask” setting in the windows kernel

nothing to do with overclocking

Oh wow, I didn't know that, thanks for sharing.

 

Oh boy, now I have another variable to test and benchmark LOL

 

I had settled on just using the TF-51 on the Caucasus map because it's free but I might run a few comparison's with Heatblur's modules. I own the Tomcat and the Viggen.

 

This is why I love these forums and flight simming and gaming in general. You can never stop learning how to get the peak performance out of your system, there's always something new to explore. I honestly spend more time building, tinkering, and testing than I do just gaming.

 

It's not unusual for me to start a new game, get the graphics and mods installed and tuned, and then get bored and start tuning a new game. :huh:

I don't think it makes any difference, because it doesn't matter if you have 6 or 5 unused cores (in a 8 core cpu)

i’m not taking about overclocking, i’m saying that if you or DCS does not set core affinity in a way to limit the number of cores that can be used, then the task scheduler in the windows operating system will schedule any “ready-to-run” thread onto any available cpu core it wants to use.

(i.e. it will not limit the “ready” threads to specific cores)

 

thats the whole point of the core “affinity mask” setting in the windows kernel

 

nothing to do with overclocking

Intel Turboboost chooses that fastest cores automatically unless the user manually turns it off. And Turboboost is an automatic form of overclocking from the CPU's stock baseclock. I don't set core affinity manually, I never said I did. DCS's rendering thread settles on logical core 15 in my Afterburner OSD automatically with no intervention on my part. It's pretty easy to test this yourself. I recommend MSI Afterburner if you don't use it already. It's shareware and works with all graphics cards.

https://www.intel.com/content/www/us/en/architecture-and-technology/turbo-boost/turbo-boost-max-technology.html

Here's a screenshot from some SLI benchmarks that I'm doing. I just have the stock overclocks enabled in BIOS and the High graphics preset for these tests as a baseline. As you can see Logical Thread 15 (Physical Core 8 ) is at 97%. That's DCS's rendering thread that's sending draw calls to the GPU. The one GPU being used is also at 97%. This is how you know you are at peak performance. The CPU's limiting factor is single thread IPC. A 9900K will slightly outperform a 8700k or 9700K (no hyperthreading), but not because of more cores or HT, it just has faster single thread performance. AMD's newest line matches or surpasses an average 9900K in single thread performance. The recent KS "special edition" is just a high binned 9900K as over time they perfect the lithography processes and QC and get better chips from when they were first released. That's why I buy my processors from Silicon Lottery. They test and bin processors for higher clocks.

https://www.cpubenchmark.net/singleThread.html

CPUs and DCS CPU Usage

that’s interesting.

do you know if all DCS execution threads are taking turns on core 15 (97% utilization) or do they run concurrently on the other available cpu cores?

it seems unlikely they would take turns. the developers would have to add explicit synchronization boundaries and thread safe code sections to enforce that.