low frame rates on higher end pc; better fps on weaker machine

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703m
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low frame rates on higher end pc; better fps on weaker machine

Post by 703m » 18 Oct 2017, 21:29

PC1 specs:
Windows 7 Sp1 Ultimate
CPU - AMD FX-8120
GPU - r9 290x Windforce 4GB
RAM - 14GB
Storage - 7200rpm 1TB HDD

Framerate: 2-40fps, but mostly hovering at 22 when walking about the world and around 43 in interior cells. 4-16 fps in most towns or densely populated areas, e.g. the Dren plantation

PC2:
OS Windows 10
CPU - Intel Pentium G3258
GPU - Nvidia GTX 950 2GB
RAM - 16GB
Storage- 7200rpm 1TB HDD

Framerate: 16-200fps mostly at 55 to 60 occasionally hitting 1-5 fps in Ebonheart. 60-180 walking about the world. Often has greater than 300 fps inside interior cells.



Both machines are running the exact same texture/model mods and plugins. The config files are also exactly the same sans some gameplay tweaks on the higher end one (Red cursor on theft, toggle sneak, etc.)

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raevol
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Re: low frame rates on higher end pc; better fps on weaker machine

Post by raevol » 18 Oct 2017, 21:54

Sorry, the "weaker" one is the one with more RAM, a newer video card, and a newer OS? Can you clarify?

703m
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Joined: 27 Dec 2016, 10:26

Re: low frame rates on higher end pc; better fps on weaker machine

Post by 703m » 18 Oct 2017, 22:10

The 290x outperforms the gtx 950 in every way besides power efficiency

http://gpu.userbenchmark.com/Compare/Nv ... 3510vs2166

http://cpu.userbenchmark.com/Compare/In ... 2434vsm173
The G3258 does have a dramatically higher single core speed, but the fx-8120 has a higher multi core speed.


One assumption I made was that openmw doesn't work well with processors with many cores in comparison to processors with faster per core speed similar to the original engine, but I didn't know for sure so I posted to see if anyone could give me any other reasons for the slower speed.

EDIT: as for the ram difference; I didn't think that a 2 gb difference would make a huge impact on performance, but again, I've posted here for a bit more info.

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AnyOldName3
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Re: low frame rates on higher end pc; better fps on weaker machine

Post by AnyOldName3 » 19 Oct 2017, 00:09

The Pentium will have a seriously significant single-threaded performance advantage, and it's likely that the part of the engine bottlenecking performance is the physics system, which can only run on a single thread. If you press F3 a few times, you should see a graph showing which things are taking the most time.

Because of how the physics system works, once simulation steps start being missed, the ones afterwards take longer, and so are more likely to be missed. If the physics system is working correctly, it runs at a fixed step time and then positions are interpolated to match when frames are drawn, but frames have to wait if the data required for interpolation isn't ready.

Morrowind's physics is the one thing it definitely does faster than OpenMW. Hopefully, we'll be able to sort it out before 1.0, but it's possible that the original engine does something weird like make unreasonable approximations that happen to work because of a weird combination of bugs (it's Bethesda, so this isn't unreasonable to believe this) or actually use some secret Dwemer tech to put an Elder Scroll in RAM and just look up the results of the physics simulation in that.

703m
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Joined: 27 Dec 2016, 10:26

Re: low frame rates on higher end pc; better fps on weaker machine

Post by 703m » 19 Oct 2017, 00:22

Ah, well I guess I'll have to get around to upgrading at some point. Is it possible that there is a way I can decrease the physics delay? I'm running Morrowind Rebirth so I'm guessing that only makes things worse. Is it possible that making edits to Morrowind Rebirth E.g. removing statics, container,etc. could work towards making the performance more acceptable?

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raevol
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Re: low frame rates on higher end pc; better fps on weaker machine

Post by raevol » 19 Oct 2017, 01:11

I think AON3 has you covered, but thanks for clarifying, I just wasn't sure about the question! Definitely fingers crossed that we can get some physics optimizations, but if you are not yet running the latest daily, try that too, as I know some optimizations have made it in over some value of recent commits.

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psi29a
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Re: low frame rates on higher end pc; better fps on weaker machine

Post by psi29a » 19 Oct 2017, 06:55

Just because it's newer, doesn't mean it is better. Things like L1, L2 and L3 cache sizes make a huge difference and Intel usually wins that. OpenMW will always do better on strong cores with higher clock-rate, even if there are fewer of them such as with Intel CPUs and Nvidia GPUs, even ones several generations older than the latest AMD offerings with many cores but lower clock-rate.

This might change in the future, but until a developer with AMD gear comes helping or someone donates AMD gear to developers, this won't likely change.

Having many cores is great if you have an application that can distribute the load evenly and predictably like streaming encoding/decoding or other problems involving lots of data that can be chewed on in parallel, games are typically not that kind of application. That being said, we're far from optimized. :)

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AnyOldName3
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Re: low frame rates on higher end pc; better fps on weaker machine

Post by AnyOldName3 » 19 Oct 2017, 13:51

AMD's single-threaded performance isn't actually that far behind Intel's any more now they've released Ryzen. It's just that Bulldozer and its derivatives sucked. A good Intel processor is still faster in OpenMW than a good AMD one, but potentially not enough to justify the extra cost per core.

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