Virtual-Chris

This sim is so frustrating. Two steps forward, one back with every release. Although I guess it’s better than the early days where it was one forward and two back 😛

I had a very similar issue tonight by the sounds of it. I’ve been away from the sim for a month, and got a new 4090 today, so updated the sim, drivers, disabled all add-ones (except GAIST which I forgot was in my actual community folder and not symbolically linked). I then flew a 30 min VFR flight in the Kodiak, and for the first time ever, experienced an episode of 15-30 seconds of single digit frame rates. I seriously thought the sim had crashed and was about to bail, but it came back to life. It was the oddest thing. I was very concerned my new GPU was borked. 🥵 So I ran a number of other benchmarks and games this evening without incident. I hope it’s something in the sim. Maybe GAIST? But if so, this software is such an unpredictable mess. 🤬

I think as a 4090 owner, you have the luxury of doubling your FPS with frame generation, which requires DX12. So even though DX12 offers less FPS, after you double it, you’re way ahead of DX11.

Would be interested in your FPS in both cases.

What FPS difference do you see between DX11 and DX12? Back when SU10 launched, I noted that DX12 wasn’t noticeably better than DX11 but ran with it. I just got a 4090 and did some more testing (with my 5800x3D). I actually get 5-10FPS less using DX12 with 4K Ultra and LOD 300 or 400 (TAA). Drone view goes from around 86FPS to 78FPS (using LOD 300) with the Kodiak on the runway. Am I alone in seeing FPS go down with DX12 now?

Yeah, I guess if time is money on a heavily multi-threaded task, the added investment in a 12-16core CPU is worth it, but if it’s just a hobby PC, that does a variety of workloads, the 5800x3D will do pretty much any multi-threaded task and give you the best performance in MSFS - it’s good bang for the buck. My guess is the sheer volume of data that MSFS has to process, even at low LOD to render the scene is why memory latency, and thus cache size, is so helpful.

More insights in this thread…

But multi-core performance means very little in this sim. Cache and singe-threaded performance is king. I actually get better performance by turning off SMT (hyper-threading) as it just means less cores competing for the same precious cache.

Why is that?

@Watsi can you comment on the possibility of VNAV ever making it out of the experimental version?

In my case, I want to be able to have the plane fly the glide slope on an RNAV approach, which I would expect is pretty common?

I'd also like to know.

If it’s on bright scenes, that’s probably some other issue. OLED G-sync flicker should only be noticeable on dark scenes. If I was you, I would start with a baseline of settings and only turn on additional settings one at a time after thorough testing. For example, try your display on its native refresh, no vsync in game or NVCP, no g-sync, and no frame limiter. Your only issue should be tearing. If you have other problems, then it’s probably time to try another game. It may be hardware, Windows, or drivers. Then enable Vsync fast in NVCP and tearing should disappear. Then try g-sync and check dark scenes for OLED flicker.

It's important to note that the flickering issue I had is the result of a combination of a dark scene, g-sync, and low FPS. This issue is a well known problem with OLED displays. In a bright scene, no VRR, or higher FPS, you shouldn't have an issue. I think the solution is a 4000 series Nvidia card with frame generation to increase FPS up to the 100+ range. Then the flickering shouldn't be an issue with G-Sync enabled. Until then I will run with VSYNC set to FAST in NVCP and G-Sync disabled. I don't have any issues with this.

Last gen, the 3080 was a relative bargain. The 4080 is now double the 3080s launch price. I think if you can stomach the cost of the 4080, you might as well just spend marginally more for the 4090 to get the best. It has substantially more cores and vram. The 4080 is 2/3rds the capability of the 4090 for 3/4 the price. It’s not a good value. Certainly not like the 3080 was. It’s in stock for a reason. Few are buying it. Get the Nvidia FE 4090.

I guess my point was that if you can afford the 4080 at £1,300-1,500, what's another few hundred for the 4090?... either one is basically an admission that money is no object when it comes to your graphics card - just get the best.

Lots of reports on Reddit of 4080s in stock at many retailers. So I think people are smartly avoiding this card. It’s not good value. If you can afford a $1200USD graphics card, you can probably also afford the 4090 or just save a bit more for it.

Sounds like it’s largely down to owners not seating the cable in the socket fully... User error.

That wouldn’t surprise me. When the 30-series released, there were reports of some cards locking up at high boost clocks… so they lowered the max boost in a driver update. I expect they will solve this the same way: Lower performance to reduce the fire hazard rather than fix the connector.

Not surprisingly, on my iPad they look the same. I don’t think you can just take a screen shot of HDR and share it here and expect the difference to be visible. But also make sure you are using the Windows HDR utility to calibrate the white point to the max luminosity of your display. Your settings or lack of proper settings could be creating a tone map that doesn’t take full advantage of your display. Then look for blown out highlights vs more definition in the highlights… like the sun and clouds lit up by the sun.

Do you have a 4000 series car with DLSS3?

I don't feel that input lag or response time are a major factor in my enjoyment of the flight simulator like it can be in a competitive shooter. I think DLSS is ideal for situations where the engine is main thread limited, struggling to feed your GPU, and as a result you're getting slide show like FPS that starts to look like a movie shot on film. If the GPU can smooth panning in these situations, that's all that matters. I don't need better response times, just smoother rendering of the response I have. 🙂 In fact, I can't think of a better application for DLSS than a flight simulator... lag is inconsequential, the rendering can be largely main-thread limited, and any (artificial or otherwise) boost in the FPS is a welcome improvement.

@Cpt_Piett would you care to comment? I recall you stating that DLSS3 was a saviour in these situations where the FPS tanked at large airports.

As I mentioned in another thread... It seems that AMD has announced something similar to DLSS3 but it won't be here until next year, and it remains to be seen what kind of support is required from games and how well that will take off. I think for flight simulation, DLSS3 seems to be a saviour for those moments when FPS goes down the toilet with study level airliners and demanding airport scenery packages so Nvidia seems to be the smart investment for now.

It seems that AMD has announced something similar to DLSS3 but it won't be here until next year, and it remains to be seen what kind of support is required from games and how well that will take off. I think for flight simulation, DLSS3 seems to be a saviour for those moments when FPS goes down the toilet with study level airliners and demanding airport scenery packages so Nvidia seems to be the smart investment for now.