Low CPU & GPU use but low FPS?

[757 Fanatic 0]

Alright, so to test things further, I went to a really remote airport with little to no building data in X-Plane. YPKA - Karratha, Australia.

GPU usage is around 25% on each... should be able to reach 50% on each if X-Plane is not SLI friendly. If it is, then 100%.

CPU total usage is about 9%. Highest usage on a single thread is about 40%, rest have very little usage, around 5%.

FPS is about 28, which in my opinion is dismal for how little it has to render. I'm sure you'll agree when you see my settings;

NOTE: I am not actually running 5760 x 1080 at the moment, only 1920 x 1080 in windowed mode.

 

An i7 4790K processor would be better than the one you have. It is FASTER, which is all that matters for X-plane/FSX. I have mine overclocked to 4.7GHZ and am getting 30-60 FPS in highly detailed areas like London Heathrow with addons.  This is at 4K resolution. Like you, I am also using a GTX 970. What is the base speed of your CPU? I advise you to turn down number of cars to Siberian Winter, as this will take a huge load off your CPU. I would also change the shadow settings to overlay or static. I would turn on HDR rendering and set screen anti-aliasing to 2X.

 

You can see my settings/FPS here:

 

 

forum.avsim.net/topic/468892-4k-monitor-gives-higher-fps-with-no-noticeable-loss-of-quality/

[Old_As_Dirt 160]

CPU Mark Relative to Top 10 Common CPUs
As of 31st of May 2015 - Higher results represent better performance

 

Intel Core i7-5820K @ 3.30GHz

12,956

Intel Core i7-4790K @ 4.00GHz

11,238

Intel Core i7-4770K @ 3.50GHz

10,208

Intel Core i7-4770 @ 3.40GHz

9,865

Intel Core i7-3770K @ 3.50GHz

9,608

Intel Core i7-3770 @ 3.40GHz

9,371

AMD FX-8350 Eight-Core

8,982

Intel Core i5-3570K @ 3.40GHz

7,160

Intel Core i5-2500K @ 3.30GHz

6,470

AMD FX-6300 Six-Core

6,356

Intel Core2 Quad Q6600 @ 2.40GHz

2,992

PassMark Software © 2008-2015  

[Blakeman 0]

My CPU is OC'd to 4.5Ghz, and even though it has 200mhz slower clock speed, it has 6 physical cores and probably slightly better single-core performance and better power consumption.

I have messed around with all sorts of different settings, starting with the default ones for X-Plane. Nothing performs anywhere near as well as I feel it should. There is something wrong.

[Old_As_Dirt 160]

 

 

I have messed around with all sorts of different settings

 

Have you tried it without any OCing?  I have seen some who said that OCing presents some problems.  I use a plain Jane i7 4770 and a GTX 770  and get much better FRs and my renderings are set much higher.

 

John

[Slayer 190]

I wonder if this is the bug with having threaded optimization turned on or auto in Nvida control panel. Have you tried turning it to off yet?

[Blakeman 0]

Neither thing helped. I have no idea how the poster above can even get close the frames he suggests in a dense area at 4k when I barely touch 30fps in a desert at 1080p. The moment I try to spread out onto all three of my monitors (still only 3/4 the pixels of 4k), my frames halve.
I guess I'll just go back to the constant OOMing that is 32 bit P3D... at least it runs with a decent amount of FPS.

[Slayer 190]

If nothing helps then disable SLI and give it another test.

[Blakeman 0]

If nothing helps then disable SLI and give it another test.

 

Tried that, still identical frame-rates. After some more testing and tweaking, I'm feeling more and more like this issue is CPU-related.

Is X-Plane known to not play nicely with multiple cores? Will turning hyper-threading off improve the situation, you think?

[MikeMJD 2]

Was it better before xplane updated to 10.36 ?

[Longranger 148]

My CPU is OC'd to 4.5Ghz, and even though it has 200mhz slower clock speed, it has 6 physical cores and probably slightly better single-core performance and better power consumption.

Well, OC doesn't necessarily help X-Plane. X-Plane puts more load on the connection between the subsystems. if the system can't keep up with the data transfer its performance will suffer. My first try on a OC#d system would be: deacivate the overclocking and observe.

[Slayer 190]

XPX can hit your hardware hard, are you absolutely sure your CPU isn't throttling? Previously my 4.8 Ghz OC that I used on FSX and P3D was no good on XPX - The CPU started cutting clocks due to heat and I'm on liquid cooling. I had to drop to 4.4 for XPX.

 

As far as core usage I can't say for sure. I run all 6 with hyperthreading on, not sure if its so sensitive to affinity masks like FSX etc.  You can always go into task manager after it's running and manually set affinity to see if there is a change. Right click the process and pick set affinity.

[rdb 44]

Is X-Plane known to not play nicely with multiple cores? Will turning hyper-threading off improve the situation, you think?

 

 

I run 3930k @ 4.2 Ghz with HT on (12 threads) and haven't encountered any problems.

There is definitely something wrong with your setup. I get waaaay better performance even with complex 3rd party planes and sceneries on my system (GTX 980, 3440x1440).

 

[Blakeman 0]

So today I made a few discoveries - turning off hyperthreading helped a little. Gave me a small performance boost (5 or so fps in a dense area).

However, I've always run relatively low FOVs when I fly, to try have a more realistic sense of scale. I've noticed that having a higher FOV DRAMATICALLY increases my FPS. I'm not sure why. Perhaps its because %-wise, my screen is taken up by more of the cockpit. I'm not sure.

[mdavis 10]

Systems that have been upgraded in pieces often show bottlenecks between components, especially the mobo transfer rates, RAM limitations and other factors.  In other words, an older component (mobos especially) don't always support faster GPU and RAM transfers.

 

Having said that, I backed my i7-4790K down to default 4.0GHz for a quick framerate test.  Since this beast automatically shifts to turbo mode under load, it was always at the 4.4GHz speed whenever I checked it with XP 10.36 loaded, so that is the actual default for that CPU.  (It's only 4.0GHz at idle.)

 

I'm using a single 1920x1200 monitor, running in windowed mode, a GTX980 Superclocked GPU (4GB VRAM), Win 8.1 on an SSD and XP on a fast 4TB HD with 64GB cache through a SATA3 6GB/sec cable, and 32GB of RAM.

 

I do NOT compress textures to conserve VRAM.  Textures are "extreme", trees "filled in", objects "mega-tons", roads "tons", cars "Siberian winter" (which I find plenty), world detail distance "very high", airport detail "extreme", shadow detail "low", water "default", all special effects ON, HDR "FXAA" (higher settings show me almost no improvement and suck framerates), anisotropic 2X, and cloud detail is irrelevent because I use SkyMaxxPro2.0 which doesn't use the XP setting.  Set this very low if you're using default XP clouds - maybe around 20-40%.

 

In the nVidia control panel, the only changes I've made is Power Management -> Prefer maximum performance and Threaded optimization OFF.  I don't know if either of these really matter but someone said they did, I changed them and haven't bothered to test for improvement.  They work fine so, if it ain't broke ...  The "big boys" tell us that extra cores only facilitate scenery loading and AI traffic.  The real factor is CPU speed.

 

I have played around with increasing some of the Rendering settings, but this is the sweet spot where things look fantastic and I have a big reserve of framerates when entering extremely dense scenery areas, flying complex aircraft or doing anything that loads the system.  I have HD and UHD mesh where available.  I have never seen framerates below about 35 fps at major airports with lots of moving 3D objects.  Typical enroute frames run from 55-85 fps depending on what's loaded below, and I've seen well over 100 fps in many remote areas.  I can push a couple of these settings, but the gain is effectively nil.

 

As I mentioned, I run SkyMaxxPro2.0 for clouds.  I also have either FS Commander or Plan-G loaded at the time I'm flying.  Using XP in windowed mode (I've never tried full screen to see if that is better or worse on framerates) and use their moving maps as a toggle from the taskbar at the bottom of the screen.  The i7-4790K handles those in the background with no apparent framerate hit, and I have plenty of RAM to keep them active, something I couldn't do in full screen mode.

 

If you have multiple monitors, you really need to watch VRAM loading.  If you push rendering settings, you really need to watch VRAM as well.  And your monitoring should be done in those areas in which you have the maximum scenery load - complex 3D panels, big complex airports, lots of heavy weather/clouds, etc.  Weather is a huge factor.

[Old_As_Dirt 160]

Very good write-up mdavis,

 

I have built and added to many computers since the early 90s, and have found what you said about partial builds to be true.  It is always best to get all new components and build from scratch.  I think that you can get around some of the problems by buying the best compatible motherboard you can find for your existing components, if money is a factor - and it usually is.  These are relatively inexpensive (but require a total tear down) and will assure the fastest transfer of data across the busses and is often overlooked when upgrading.  The poster has a pretty good match of CPU (even though there is some question) and GPU (I don't recall DRAM being mentioned), so there has to be a bottleneck between the two. 

 

John.