Low CPU usage?

[sjb5001]

I was wondering if anyone else experiences this: when I'm running a DCS World simulation, my CPU usage is only 15-18% and my RAM usage is about 50%, yet I experience quite a bit of stuttering in major cities or if I have CPU intensive options selected, such as CIV TRAFFIC. I know it's not a GPU bottleneck because I get the same results no matter what resolution or graphic selections I run the game with.

 

Why isn't the program utilizing my processor to it's fullest capacity? Is it because I have a multi-core processor? I'm a little disappointed that my processor is barely idling when running DCS World. Anyone have any solutions?

 

PC specs:

 

3.5 GHz AMD-FX 8320 (4-cores, 8-logical cores)

8.0 GB RAM

AMD 7870 w/ 2 GB of RAM

Windows 8 Pro, 64-bit

[Devrim]

I realized it too. My system is in my sign.

As you said, CPU doesn't exceed %15...

[EtherealN]

yet I experience quite a bit of stuttering in major cities or if I have CPU intensive options selected, such as CIV TRAFFIC.

 

For cities, this is most likely load-stutter. Your CPU and GPU can only handle data when it has been loaded into memory from your hard drive. If the hard drive is slow (or the file system fragmented etcetera etcetera), both CPU and GPU will sit there having to wait for their data, and you get what is called a "load stutter".

 

I know it's not a GPU bottleneck because I get the same results no matter what resolution or graphic selections I run the game with.

 

While I agree with your analysis (it probably isn't the graphics card), please remember that there are more components than the GPU on your graphics card. There are several options, like the "scenes" setting, that can have a considerable impact on vRAM, at which point your graphics card's memory controller can be a bottleneck - at which point you'll see low utilization on your GPU since it doesn't have enough to do.

 

The above mainly for future reference, I agree that you probably don't have to worry about the graphics card here.

 

Will note though that the 7870 and it's siblings have unfortunately been a bit spikey lately on their own, though this varies greatly with specific games.

 

And finally to make sure everyone understands this is not a problem exclusive to AMD:

 

So it is possible that this could cause some of your problems, though I doubt it.

 

Why isn't the program utilizing my processor to it's fullest capacity? Is it because I have a multi-core processor? I'm a little disappointed that my processor is barely idling when running DCS World. Anyone have any solutions?

 

PC specs:

 

3.5 GHz AMD-FX 8320 (4-cores, 8-logical cores)

8.0 GB RAM

AMD 7870 w/ 2 GB of RAM

Windows 8 Pro, 64-bit

 

Your processor's design is, unfortunately, not really designed for computer games, IMO. Also, your classification of it as "4-core with 8 logical cores" is incorrect. It is a CPU with 4 "modules", where each module has two integer cores but fetcher, FPU, decoder etcetera are shared. Thus it becomes sort of incorrect to say that it's an 8-core, but it is also sort of incorrect to say that it's a 4-core. What can definitely be said though is that there's no differentiation between real and logical cores on that processor.

 

The probelm then is that we have two threads to play with, on a sort-of-8-core processor. This means that the maximum theoretical utilization you'll ever see on that processor is somewhere between 25% and 50%, depending on how the resources land (and how utilization gets interpreted*). It would only be 50% if two "modules" have their instruction pipeline fully saturated to feed the FPU or something like that, but that is extremely unlikely.

 

Anyways, for those stutters you have described I am afraid that the most interesting component was not on your hardware specification: your hard drive. If it's a re-used mechanical drive of some age, you might want to consider replacing it with either something that is simply faster, or an SSD. If you already have an SSD on there and this is what you are using, then we'd have to consider some other things.

 

* Most utilization meters are not very good at giving proper information, since they have to work through proxies. For example, it is entirely possible for my i7-2600K to be completely and fully saturated but still only show 50% utilization; if HyperThreading is active, I have 4 threads running (thus on 8 logical cores but only 4 actual cores), and said 4 threads saturate one core fully each. If I ran the same task with HyperThreading turned off, the exact same situation would report as 100% utilization.

[SkateZilla]

just call it hardware hyperthreading and call it a day.

[sjb5001]

It's possible it's the hard drive. It's brand new, but it's a WD 250GB Blue Drive 7200RPM, in case anyone is wondering. Not exactly a performance hard drive, but for whatever it's worth, it's the only thing that substantially holds back my Windows Experience Index lol.

 

After fiddling with the settings, I've noticed that turning VISIB RANGE from HIGH to MEDIUM is the only thing that makes a considerable difference with performance on my system. With the setting on MEDIUM (resolution at 1920x1080, 8xQ AA, CIV TRAFFIC on HIGH, and MIRRORS on), the game runs smooth as glass except for those darn rocket and cluster bomb explosions!

 

I guess that's the sweet spot for me. :thumbup:

Edited January 12, 2013 by sjb5001

[doveman]

So what rate does DCSW need to be fed data by the HDD at on full settings?

 

I find it interesting if it needs more than the average HDD can supply because I was reading a thread on the X-Plane forums the other day where they were saying that a SSD was a waste of money and wouldn't be necessary until the (imaginary) day when it had centimeter photo-realistic scenery (which would require petabytes to store) and I imagine X-Plane probably has more complex scenery to load than DCSW.

[doveman]

Will note though that the 7870 and it's siblings have unfortunately been a bit spikey lately on their own, though this varies greatly with specific games.

 

 

And finally to make sure everyone understands this is not a problem exclusive to AMD:

 

So what's causing this problem (I'm not sure what problem they're showing, just that it's called "Time spent beyond 50ms"), because they seem to show that practically every current and last gen card, both AMD and Nvidia, suffer from this problem in some games. It would seem unlikely that both companies have messed up their drivers at the same time, so is it a Windows Update that's caused it?