Performance Bottleneck = RAM

I've discovered that your RAM can be one of the main reasons DCS can have performance issues.

I've been running 2.5 using VR for a while now, and have tried everything possible to boost performance. I found that overclocking my CPU to 4 ghz helped, and overclocking my memory from the base 2200 to 3200 finally stopped the annoying flashes I was getting. But, with the textures and viewing distance set on high, I would still get stutters.

My CPU usage doesn't get above approximately 35% and my graphics card stays at around 50% when flying around the Caucuses with everything set on high, in a heavy mission. My total memory usage with DCS running in the same mission was shown as being only 12 Gb of my 16Gb.

I decided to install an extra 16 Gb of the exact same memory to see if having more actual physical memory would help, and I also reduced my pagefile to 4 Gb in the hope that maybe it had got fragmented, and by resizing it, might help it performance wise.

Unfortunately I couldn't overclock the 32 Gb no matter what I tried, and my performance went back to being below average with the flashing taking place.

I then removed the extra 16 Gb, loaded up DCS, went to fly in a mission, and DCS crashed out to the desktop. I tried a number of times, before I remembered I'd reduced the size of the pagefile to 4 Gb. But, Task Manager told me I was only using 12 GB of physical memory, so with 4 Gb of physical memory still available, why was DCS also using the pagefile?

It appears that DCS is using the pagefile as soon as I start flying in a mission! You would think my physical memory would be maxed out before this. I set the pagefile back to system managed, and I could fly in DCS once more. Luckily my windows pagefile sits on an SD drive - but it is still a performance hit.

So the lesson I would like to share, is that if you just have 16 Gb of ram, there is a good chance that as soon as you start flying, your system is using your pagefile. If this isn't on an SD drive, then your performance is going to suffer. This is different from having DCS installed on a separate SDD.

If you don't have fast memory, your performance is going to suffer - even if you have a great graphics card and a fast CPU.

If you have a good CPU, good graphics card and 32 Gb of fast RAM - DDR4 running above 3200 mhz, then you should have good performance.

It would appear that fast memory is much more important than multi threading in providing better performance.

My 32 gig ram runs at 2900 mhz, no probs here.

Remember ram these days get hot. So bad ventilation and ram pushed to the limit is a bad combo.

My system won't even post beyond 2900 mhz.

Pushing system to ,let s say, 110 % of factory spec, then you in unknown territory.

Humor me and run stock on system. With stock i mean, by any means use the factory boost options.

It only takes one bad capacitor to make weird problems , if you overclock cpu gfx card and ram, then u just tripled your chance of problems.

I run dcs in mid 60'ties fps on missions.

Overclocking is a marketing tool first and real gain at number 100. ;)

Well i still have 8 GB i dont have stutters cuz pagefile is in the SSD but having some FPS drops while getting into the combat sometimes i have to restart the game to fix the FPS problem.

How do you check where your pagefile is located?

In my observation RAM speed helps DCS Rift VR, no doubt. So to CPU and GPU. If you have 32GB just let Windows manage the pagefile in my experience pagefile reads/writes are minimal during DCS play with 32GB.

You might need to look at hardware/drivers/overclocking if you are getting regular crashes, I have been on DCS stable version since I built this rig and so far DCS has been rock solid stable and flyable. :thumbup:

If I may ask, what do guys think about my system in the spoiler below?

------------------
System Information
------------------
        Operating System: Windows 10 Pro 64-bit (10.0, Build 17134)
                    BIOS: 4207 (type: UEFI)
               Processor: AMD Ryzen 5 1400 Quad-Core Processor (8 CPUs) ~3.8GHz
                  Memory: 16384MB RAM
               Page File: 8883MB used, 23819MB available
        User DPI Setting: 96 DPI (100 percent)
      System DPI Setting: 96 DPI (100 percent)
         DWM DPI Scaling: Disabled

---------------
Display Devices
---------------
          Card name: NVIDIA GeForce GTX 1050 Ti
     Display Memory: 12177 MB
   Dedicated Memory: 4018 MB
      Shared Memory: 8159 MB
       Current Mode: 1920 x 1080 (32 bit) (59Hz)

Should I get 32 GB?

If I may ask, what do guys think about my system in the spoiler below?

 

 

------------------
System Information
------------------
        Operating System: Windows 10 Pro 64-bit (10.0, Build 17134)
                    BIOS: 4207 (type: UEFI)
               Processor: AMD Ryzen 5 1400 Quad-Core Processor (8 CPUs) ~3.8GHz
                  Memory: 16384MB RAM
               Page File: 8883MB used, 23819MB available
        User DPI Setting: 96 DPI (100 percent)
      System DPI Setting: 96 DPI (100 percent)
         DWM DPI Scaling: Disabled

---------------
Display Devices
---------------
          Card name: NVIDIA GeForce GTX 1050 Ti
     Display Memory: 12177 MB
   Dedicated Memory: 4018 MB
      Shared Memory: 8159 MB
       Current Mode: 1920 x 1080 (32 bit) (59Hz)

My CPU, RAM and GPU are already overclocked.

 

 

Should I get 32 GB?

No

If I may ask, what do guys think about my system in the spoiler below?

 

 

------------------
System Information
------------------
        Operating System: Windows 10 Pro 64-bit (10.0, Build 17134)
                    BIOS: 4207 (type: UEFI)
               Processor: AMD Ryzen 5 1400 Quad-Core Processor (8 CPUs) ~3.8GHz
                  Memory: 16384MB RAM
               Page File: 8883MB used, 23819MB available
        User DPI Setting: 96 DPI (100 percent)
      System DPI Setting: 96 DPI (100 percent)
         DWM DPI Scaling: Disabled

---------------
Display Devices
---------------
          Card name: NVIDIA GeForce GTX 1050 Ti
     Display Memory: 12177 MB
   Dedicated Memory: 4018 MB
      Shared Memory: 8159 MB
       Current Mode: 1920 x 1080 (32 bit) (59Hz)

My CPU, RAM and GPU are already overclocked.

 

 

Should I get 32 GB?

Get a better GPU first.

^ Yeah maybe even better CPU first. DCS really likes fast cores, fast GPU's and fast RAM.

:thumbup:

You should never run without a page file present. The size of your page file can be set to a minimum of 1x your physical RAM +257MB (for crash dumps). Technically, GiB in RAM terms, multiply by 1024 (ie: 16GBx1024=16384MB+257MB=16641MB page file). There are several reasons for this:

A. Most applications will simply fail when they hit their 4GB addressing limit or the OS decides to page it to disk, because it cannot, and will throw an unhandled exception (crash) for object (page) does not exist, since it was disposed of and is no longer referenced (instanced).

B. Some applications will assume a page file exists, and will simply refuse to run without one, returning 'insufficient memory', due to the above concerns.

C. Without a page file, any cached pages are simply flushed from RAM, and must be reloaded from disk, which increases overhead as all the objects need to be rebuilt.

D. Memory crash dumps cannot be performed for BSODs.

E. Unable to Sleep/Hibernate the PC without a page file.

F. The page file will rarely be used, assuming at least 20% free RAM is available.

In fact, running without a page file can only decrease the performance of applications.

As for DCS, it apparently needs lots of VRAM. All other concerns are secondary. I'm running it on an i5-3570k @3.4GHz and it's using 25-50% CPU. Also running 55-65 FPS on an ancient video card, but it lacks the VRAM for high resolution textures. Still runs them at 45-60 FPS though (with stutter due to VRAM preloading/unloading).

Hmmm, this is awkward. Did a bit of profiling, and DCS is writing to the page file at 1MB/sec, with 4GB RAM remaining, using a virtual size of 22GB??? Not all of that is necessarily page file though, they could be memory mapped asset files, but it's still hitting pagefile.sys for 1MB/sec. ;\

 

As for DCS, it apparently needs lots of VRAM. All other concerns are secondary. I'm running it on an i5-3570k @3.4GHz and it's using 25-50% CPU. Also running 55-65 FPS on an ancient video card, but it lacks the VRAM for high resolution textures. Still runs them at 45-60 FPS though (with stutter due to VRAM preloading/unloading).

I also run on a 3570k and just upgraded my gpu from a gtx770 to a Vega 64. Because of this I was running dcs with the AMD Radeon overlay on while I experimented with undervolting and such. One thing I noticed is while loading up a multiplayer server my video ram increases beyond the 8Gb my card actually has available to over 9Gb (and once to 12Gb). When loading up a mission the loading goes very quick until it gets to the end, then seems to pause for a bit. This is the part where both my Vram and regular Ram increase in size so I’m assuming that the server (104th) has lots of ram eating scripting or objects.

Sent from my iPhone using Tapatalk

I3570K @ 4.5Ghz, 16Gb DDR3 @ 1600, Vega64 @1080p

I guess I should have added that I’m running solely in VR, which adds another level of complexity, but my main point is that I was surprised that DCS uses the pagefile even when there is physical memory available. It’s also interesting to see that even with 32 gb of RAM, it still uses the pagefile.

My 32 gig ram runs at 2900 mhz, no probs here.

 

Remember ram these days get hot. So bad ventilation and ram pushed to the limit is a bad combo.

Good point - but my system is water cooled and also runs underneath an air conditioner. Under load my RAM never gets above 46c. The hottest my graphics card has got is 50c but on average sits at 45 c, and the CPU sits at around 35c

My CPU usage doesn't get above approximately 35%

DCS is single-thread, 35% CPU => CPU Core bottlneck.

Hmmm, this is awkward. Did a bit of profiling, and DCS is writing to the page file at 1MB/sec, with 4GB RAM remaining, using a virtual size of 22GB??? Not all of that is necessarily page file though, they could be memory mapped asset files, but it's still hitting pagefile.sys for 1MB/sec. ;\

Yes - I agree, and would never run my PC without a Pagefile.

That is really interesting to know that even with 32Gb of RAM, DCS still uses the Pagefile - thanks.

DCS is single-thread, 35% CPU => CPU Core bottlneck.

That's what I used to think, until I saw DCS start to use the pagefile as soon as I started a mission.

Maybe the reason the CPU and Graphics card aren't being maxed out, is because it is waiting on the slowest communications pipe to complete its work - which is reading and writing from the pagefile?

How do you check where your pagefile is located?

It's not something you normally need to worry about, and in Windows 10, it seems to be set on your system drive, and is automatically managed.

I was just trying everything I could think of to maximise my performance, and that was how I stumbled across the fact that it could be a bottleneck, and shows the advantage of having a SSD for your system drive.

If you still want to know about the pagefile, check out here:

https://www.tomshardware.com/news/how-to-manage-virtual-memory-pagefile-windows-10,36929.html

Maybe the reason the CPU and Graphics card aren't being maxed out, is because it is waiting on the slowest communications pipe to complete its work - which is reading and writing from the pagefile?

Watch the load on all cores. If at least one core is loaded ~100%, this is most likely a Core-bottleneck.

Here’s a thought, if you have enough RAM, is it possible to run the page file on a ramdrive?

Watch the load on all cores. If at least one core is loaded ~100%, this is most likely a Core-bottleneck.

solid advise here ^^^^... watch out for core saturation... if DCS is putting too much on the primary core by default,... it will be hell with stutters on heavy missions... While many will argue that you need a faster cpu (which is always a good thing), what you need to watch out for is how you are utilizing the cpu you have... on some systems, DCS will run on one primary core for simulation and one for audio... if that is the case on your system, that primary core is likely to get over saturated inducing stutter and hangs... to remedy this, you need to split the core affinity to spread the load... I dedicate 6 cores to DCS.. at only 3.7ghz (no OC)... and have it locked at 60fps.. with the primary core split, none of the cores ever even come close to full saturation...

DCS does of course respond differently with every hardware configuration..

Ryzen 2700X stock, 64GB Ram disabled page file, 25 player online. Preload radius 100, more preload radius more memory usage and more stress the system! Sorry bad english!

Ryzen 2700X stock, 64GB Ram disabled page file, 25 player online. Preload radius 100, more preload radius more memory usage and more stress the system! Sorry bad english!

That's one mean system. Even though you have disabled the page file, it would seem your system is still using virtual memory.

Here’s a thought, if you have enough RAM, is it possible to run the page file on a ramdrive?

I thought the same thing! It seems that Windows has to have physical memory to store the pagefile so that it can shuffle 'stuff' including a crash log onto it. I also think that DCS may store it's crash log/data into the pagefile, and maybe other data it doesn't need quickly - to reduce the amount of physical memory it uses?

I went investigating faster SSDs and discovered that the latest and greatest NVME all seem to state that the biggest benefit is to gamers, to stop stutters and frame drops. Why - because they drastically increase the speed of access to the pagefile.

 

I went investigating faster SSDs and discovered that the latest and greatest NVME all seem to state that the biggest benefit is to gamers, to stop stutters and frame drops. Why - because they drastically increase the speed of access to the pagefile.

:music_whistling:

@O/P Just beware you get hit 6 points against an activation for Starforce DRMed content.

AFAIK this still applies to Starforce DRM

As for pagefile usage I really don't see much activity during game play.

With this "9600K test rig" system and my i7 5930@4.7GHz, CPU, RAM and GPU all impact on Rift VR performance. The condition that DCS would use pretty much 2 cores whilst the rest of the cores did pretty much nothing at all, that changed osme time ago and it improved more some months ago, at least for Rift VR. I am not suggesting DCS is "more multi threaded" I just think Windows10/Rift are more able to off load work to other cores as I was struggling to get 16% DCS CPU usage and total maybe 20% CPU usage even with iTunes in background before with yes 1 core maxed out pretty much.

RAM amount is possibly a contentious point with many different views I have only either had 32GB or 64GB and simply have never ran DCS with less. But I also have never seen large amounts of disc writes during game play, as you can see here also note CPU usage total, DCS can get up low 40s % itself but averages around 30%.