Thinking about improving FPS, a path to optimizing?

Emery

Emery

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As the cars have become more detailed, fps has become impacted (see GT3 pack). That's exasperated by DX11 features and trying to run at higher DX11 levels.

Detailed cockpits are needed for VR, so there's little desire to reduce detail there. Models made for multiple games (e.g. Assetto Corsa and rF2) means we'll continue to see higher detail on the exterior as well.

Short of a coding miracle, I think the only way to eke more fps out of rF2 is if the switch from LOD A to LOD B (and maybe from LOD B to LOD C) happens sooner. As far as I know, this adjustment is not available to the player. You might think the LOD switching is tied to Opponent Detail, but Opponent Detail only changes the textures rather than the LOD distance (which is what used to happen in older games).

In favor of this approach is that new LOD B models are about as detailed as the older LOD A models. Those older LOD A models have been fine for the majority of rF2 players over the years, so I don't think we'd be losing much by having LOD switching happen sooner.
 
Guimengo suggested that maybe 4k skins play a role in reduced fps with the newer cars. I tested that this morning with the GT3 pack (easy enough to try your own tests), but 2k skins do not improve fps for me. Lowering opponent detail from Full to Medium nets about a 10% improvement.
 
Emery said:
As the cars have become more detailed, fps has become impacted (see GT3 pack). That's exasperated by DX11 features and trying to run at higher DX11 levels.

Detailed cockpits are needed for VR, so there's little desire to reduce detail there. Models made for multiple games (e.g. Assetto Corsa and rF2) means we'll continue to see higher detail on the exterior as well.

Short of a coding miracle, I think the only way to eke more fps out of rF2 is if the switch from LOD A to LOD B (and maybe from LOD B to LOD C) happens sooner. As far as I know, this adjustment is not available to the player. You might think the LOD switching is tied to Opponent Detail, but Opponent Detail only changes the textures rather than the LOD distance (which is what used to happen in older games).

In favor of this approach is that new LOD B models are about as detailed as the older LOD A models. Those older LOD A models have been fine for the majority of rF2 players over the years, so I don't think we'd be losing much by having LOD switching happen sooner.
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You are right, LOD optimization can bring a lot (more FPS with low visual impact), it is a very long and tedious process because it differs for all the different level of detail settings in game.
Cheers.
 
"Shadow quality" is the highest fps taxing currently, possibly especially in conjunction with GT3. Anything above "low" has a big performance hit, in particular on startup with several cars in front of you. The problem is that at "low", game looks bad.
 
Interestingly none of the EGT 2015 URD models have a performance issue and they look as good as any of the GT3 pack cars.

I'm sure S397 will undertake the necessary optimisations.
 
Travis said:
Interestingly none of the EGT 2015 URD models have a performance issue and they look as good as any of the GT3 pack cars.
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If you look with a critical eye, you can tell the EGT models were made with fewer polygons. Look to the round air vents and what should be smooth curves on the mirrors; EGT models show polygons & GT3 models do not. There's also less going on in terms of textures inside the EGT cockpits.

Note I'm not saying one is better than the other; merely pointing out there are tradeoffs for performance vs. appearance. I can remember when those of us with borderline video cards thought the EGT mod was a bit heavy for GPU performance, too!
 
Agree. I can't open the encrypted GT3 GMT's to compare, but I'm pretty sure they are higher poly than URD. Also GT3 pack is using 4K textures, I don't think URD is. The other point is these new cars have to be made look good in VR. What looks good on a monitor might not be sharp enough in VR, hence the need for the 4K textures for instance.

The McLaren is provenly the same model as used in AC, so I'm doubtful how much performance can be improved from optimizing the cars. Maybe truth is that previous ISI/S397 cars were made in less detail to deal with the low FPS, but I don't think this is a good path. I notice from Afterburner that PCI Express 2.0 bus gets more or less saturated at start of race with 10 GT3 cars, so for me there is no point in buying a more powerful GPU, as it would still give the same FPS. The game engine is the part that needs optimization.
 
Emery said:
If you look with a critical eye, you can tell the EGT models were made with fewer polygons. Look to the round air vents and what should be smooth curves on the mirrors; EGT models show polygons & GT3 models do not. There's also less going on in terms of textures inside the EGT cockpits.

Note I'm not saying one is better than the other; merely pointing out there are tradeoffs for performance vs. appearance.
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Perhaps a lesson can be learnt from the URD models. As of right now, the GT3 cars from the GT pack look amazing, they are bringing all but the most powerful systems to their knees.

I'm running a single Asus ROG GTX 1070 on a MB with a PCIe 3.0 x16 slot with an OC'd i5 and I can't run 20 AI cars at anywhere close to 60fps; even with the default graphical settings as one has with a new user profile, I still get sub 60fps when at the back of a grid of 10 cars (9 being AI) at Suzuka. It's a shame as the actual cars are a blast to drive and I want a 20+ car grid without dips from 60fps.

In comparison, all of the URD mods (I own them all) run beautifully with rF2's graphical settings at their respective max settings with a 35 car grid.
 
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Emery said:
You might think the LOD switching is tied to Opponent Detail, but Opponent Detail only changes the textures rather than the LOD distance (which is what used to happen in older games).
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That is incorrect. There is a reason why you can fix the texture detail of oppents, but still make use of lower poly dense LODs.
 
I have not had any fps problems with the GT3 pack specifically.
Last night in our Apex GT3 race people reported low fps.
Most if not all of the trouble I have seen people having (low fps, crashes to desktop, servers freezing) seem to be tied to the 1.09 version.
Of course the mod may be heavier but I would wait for a version update fixing the bugs before anything else.
1.09 is not very stable atm and does not seem to be well optimized either.
 
@Travis Is that single or triple screen? If it's single screen, then I'm almost certain the GPU is not being utilized properly, because even my GTX 1050 Ti runs at 50ish FPS with 20 GT3 AI cars (post FX @ low), and 1070 should be over 2X the performance of 1050 Ti. This would prove that performance does not scale with GPU power.
 
stonec said:
@Travis Is that single or triple screen? If it's single screen, then I'm almost certain the GPU is not being utilized properly, because even my GTX 1050 Ti runs at 50ish FPS with 20 GT3 AI cars (post FX @ low), and 1070 should be over 2X the performance of 1050 Ti. This would prove that performance does not scale with GPU power.
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I run a single ASUS ROG 1080P screen.

I have a friend who has a i7 and a GTX 1080 setup and he too was mentioning a sub 60 frame rate using 30 GT3 cars at the start of a race and rising to 90+ fps as the field stretches out over the course of a race. He is using ultra PP; the 1080 is between 25-30% faster that a 1070 and I'm not surprised he has a better frame rate than I do.

At Suzuka with all settings on max, AA at level 2 (should be 4xMSAA) and PP on medium with a 32 car grid (I'm starting at the back), the starting frate rate is 50fps, rising to 90+ fps as the field stretches out.

In contrast, I can run a field of 32 Nissan GT1 cars with the exact same settings without dropping below 60fps. I can also run any other ISI and URD made vehicles without dropping below 60fps.

For a comparison, R3E runs 52 AI cars at Spa at 60fps at near max settings (the AA is set to 4x), Assetto Corsa at max settings averages 127fps in the 16 car benchmark and pCARS 2 runs a 31 AI grid in the dry around Spa without dipping below 60fps.
 
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Again, this is "Shadow quality" that kills fps with GT3 cars when there are many of them in view (thus on race start specifically). If you set it to "Low" (vs "Medium" or higher) you will gain maybe 20-30 fps on the startup grid.
This huge performance loss is definitely not normal and should be fixed.
 
bobbie424242 said:
Again, this is "Shadow quality" that kills fps with GT3 cars when there are many of them in view (thus on race start specifically). If you set it to "Low" (vs "Medium" or higher) you will gain maybe 20-30 fps on the startup grid.
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I tried this and medium didn't make a whole lot of difference. The low shadow setting helped lower the GPU load from 100% with max shadows to between 80%-85% while racing (the GT1 grid GPU usage hovered around the 65% mark) and the frame rate never dipped below 60fps with a 32 car GT3 grid.
 
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Low shadows is only using the 'baked' shadow under the cars, Medium is using low poly cast shadow gmts, dynamically.
 
Travis said:
I tried this and medium didn't make a whole lot of difference. The low shadow setting helped lower the GPU load from 100% with max shadows to between 80%-85% while racing (the GT1 grid GOU usage hovered around the 65% mark) and the frame rate never dipped below 60fps with a 32 car GT3 grid.
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Didn't try it but the performance gap between low and medium may also be associated with the opponent car detail setting, with more detail incurring more performance loss (because of more complex shadows). And also the max number of car visible setting.
 
Travis said:
Interestingly none of the EGT 2015 URD models have a performance issue and they look as good as any of the GT3 pack cars.

I'm sure S397 will undertake the necessary optimisations.
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I am not so sure because they know it since releasing the 650S GT3 but nothing changed with the other cars.
 
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