Performance Bottleneck of 2023: Your Old TV

[David Mills 4,774]

     Whenever users suffer performance issues with MSFS, the first diagnostic question is usually whether the bottleneck is the CPU or GPU. We've seen users with older CPUs buy a new and expensive GPU -- perhaps a 4000 series card -- but still endure disappointing fps due to their old CPU being unable to calculate data as rapidly as their GPU needs for the display. We call this being "CPU limited" (or sometimes "Main Thread Limited").

    We also see many instances where users have robust CPUs in their computers, but they're still using antiquated graphics cards (GPUs) from years past. The CPU is churning out the data quickly enough, but the GPU struggles to produce a display as resolute and detailed as the simmer hopes. We call this being "GPU limited."

    Due to the remarkable programming achievement that is MSFS, however, we're now seeing a new form of bottlenecking in 2023. Many users now have both powerful CPUs and GPUs. But an often-unforeseen, novel "problem" has now arisen that limits fps when using MSFS. The new "problem" is that the highly-efficient coding of MSFS, combined with a powerful CPU and GPU, now produces more fps than many TVs can properly display. In other words, MSFS is giving us too many fps! This "problem" is almost comical to consider, but it is nonetheless a problem that must be addressed for top performance of MSFS.

   This is the problem I myself currently face. My primary MSFS display is an aging Sony 4K TV, which I purchased way back in 2015. At the time, it was truly state of the art. And, as a TV, its performance still shines. But this Sony TV, like most TVs currently in use as computer displays, was never designed to produce more than 60fps. TV displays (in America at least) were originally designed to sync their standard 30fps (for TV shows) to the frequency of the incoming electrical current of 60Hz, recalling that there are/were actually two interlaced images being displayed as a single frame. (Many European nations use 50Hz electrical current and therefore 25fps for TV broadcasts.)

    So what happens if MSFS and your computer are outputting more than 60fps to a standard 60Hz TV? Nothing catastrophic happens, but the display suffers noticeable issues such as screen tearing, discoloration, herky-jerky performance, and various other graphical anomalies. The casual observer may not even notice these quirks. But the fact remains that you're never going to get more than 60fps from a TV that can only display 60fps. Period. So in 2023, you can now be "TV Bottlenecked." This is an entirely new curveball for flight simmers.

    What, then, is the solution to TV bottlenecking? I personally just lock my refresh rate (in the MSFS options) to Full Monitor Refresh Rate, which, in my case, is 60fps. (You can also cap your fps in various other ways, such as your Nvidia MSFS profile.) And I'm absolutely thrilled with the performance I get. I run MSFS at full 4K resolution with all sliders on Ultra, locked at 60fps. I don't even turn on Frame Generation even though I have a 4090. I get a perfect, stutter-free, 60fps display even on my dilapidated TV.

    But if 60fps just isn't enough for you, you'll need to buy either a dedicated computer monitor with variable refresh rate or a newer TV with a variable refresh rate (VRR). These displays are often called G-Sync or G-Sync Compatible, or Freesync, or just VRR. These displays adjust themselves dynamically to the video input signal they receive from the computer, rather than bottlenecking the video display to a standard 60fps due to their own hardware limitations.

   Five years ago, who would have thought that a new challenge for flight simmers would be too many fps? Funny but true, thanks to the efficient coders at Asobo.
 

Edited July 6, 2023 by David Mills

[sfgiants13 83]

I currently use a tv as well. Problem is certain scenarios it doesn’t want to hold 60fps so I get stutters. But, if I run it unlocked in the same scenario I get 100+ fps which gives me the aforementioned problems like micro stutters.

Bottom line is I’m waiting for a good sale on a 4k gsync monitor. 

Edited July 6, 2023 by sfgiants13

[sidfadc 1,345]

Interesting topic because I just dropped some serious cash on a 7800X3D + 4090.  The biggest headache was buying the Monitor!  I went for the Gigabyte M28U 144hz "GSync Compatible".  Yea I know before someone jumps in this is terrible because I should have bought a GSYNC Ultimate 4k monitor..........but during my research these are a) few and far between b) ridiculously priced!

So I'm going to take my chances with my *cough cough* budget £600 monitor!!!

 

Edited July 6, 2023 by sidfadc

[cianpars 1,262]

I have a G Sync compatible 2k monitor which will run at 164.84 Hz but I still choose to run at 60 Hz with V Sync limited to 30 FPS as this is what gives me the smoothness and performance I really want without causing my system to overheat in the summer.  You do make an interesting point about using a TV as a monitor though which ispartly the reason I went for the 2k monitor rather than a small 4k TV.

[GSalden 4,737]

Here in Europe most TV’s are 50 hertz. Because I wanted large displays I choose for Sony Bravia 4K 100 hertz TV’s. 

They are 5-6 years old. I have them running at 60 hertz. No GSync of coarse.

MSFS runs quiet smooth ….
 

[FBW737 530]

I'm doing 23hz for 46fps on screen or 29hz for 58fps on screen depending on the scenario with maxed out setting in MSFS on my $500 Samsung UN55NU6900 all thanks to frame interpolation for a perfectly smooth and brilliant flight sim experience. So in my case its the TV that provides the magic not the 10900k at 5.2ghz or the 3090!🤪

[CarlosF 1,273]

Why would anybody need more than 60fpm in a flight simulator. In the days of FSX and even P3D, 60fps was considered to be the Holy grail and people could only dream of one day be able to have hardware capable of it.

I'm one of those that upgraded my CPU and kept my good old and antiquated 1070. Locked at 1/3 refresh rate (40fps on a 27inch 120mhz curved monitor with most settings in Ultra) I have the smoothest sim (almost everywhere) and that is without breaking the bank on a $1200 card. Waiting for Gen5 cards and for the prices to come down a bit before I park my 1070.

Edited July 6, 2023 by CarlosF

[sidfadc 1,345]

I was rocking an i7 4790k and 1070, I couldn't upgrade my CPU without a new MB anyway and to be honest, I've had my money's worth over the last 8 years.  I'm in a fortunate position that I had some dollar to spend and decided to treat myself to a new rig.  Since I started simming back in the FSX days about 2015 I've always had an underpowered PC.  When my new rig arrives I look forward to cranking up some settings and being an FPS junkie (hopefully!) 🙂

[Bob Scott 7,848]

If you have a 60Hz fixed-rate display like a TV and your PC is producing frames faster than that, setting V-Sync should sync the video card's output with the hardware and lock the frame rate at 60.  That works well--but only provided your PC can reliably exceed 60 fps all the time.

If, however, your frame rate intermittently drops below 60Hz, then you'll see stutters, tearing etc when it does.  This isn't a bottleneck caused by the TV, it's the known behavior of a mismatch between the display's refresh rate and the output frame rate, and made worse when the rate isn't stable (e.g. high frame time variance).

When using a TV as a monitor, I prefer to use VSync and set the refresh rate to 30Hz, which I know my computer can easily exceed, with only the very, very rare excursion below that. 

[lwt1971 8,077]

Pretty much in the same situation as you David, waiting on a monitor for my new system. Given my needs for accurate SRGB/ARGB color accuracy (i.e. for photography work) had to go with a 60hz monitor, and decided on 1440p given my desk view distance. Still need to set up the system but assuming the 13900K + 4090 should be able to maintain 60fps in most situations. Given that, my questions to you and others:

1) setting regular vsync in nvcp is better than in-game frame limiting I'm assuming?

2) is nvidia adaptive vsync better? Think this is better when fps drops below 60?

3) is nvidia fast sync better? good for latency I guess but also will overwork the cpu/gpu for 60hz 1440p wouldn't it

 

Edited July 6, 2023 by lwt1971

[turbomax 3,455]

59 minutes ago, CarlosF said:

1) 40fps on a 27inch 120mhz curved monitor with most settings in Ultra)

2) Waiting for Gen5 cards and for the prices to come down a bit before I park my 1070.

1) you mean 120 Hz. MHz is Hz x 1.000 - 120 MHz is wireless, VHF radio frequency. 😀

2) Gen 5 cards not before 2025 according to industry insiders.

[David Mills 4,774]

6 minutes ago, lwt1971 said:

1) setting regular vsync in nvcp is better than in-game frame limiting I'm assuming?

On my system, I've never been able to discern a measurable difference between in-game vsync and nvcp vsync. Both work equally well on my setup. As for adaptive vsync or fast vsync, those options don't seem to be available to me when my card is connected to the old Sony TV. Perhaps I've just overlooked them. There's a part of me that hopes this TV will bite the dust and I'll get a new one with G-Sync. This will be a fairly expensive proposition, however, since I want at least a 75" OLED with the variable refresh rate capability. I must say, though, that I agree with what @CarlosF asked above -- questioning why anyone would need more than a steady 60fps for MSFS. At any (refresh) rate, I'm a very happy camper with MSFS. 

[Whiskey Tango Foxtrot 6]

11 hours ago, David Mills said:

     Five years ago, who would have thought that a new challenge for flight simmers would be too many fps? Funny but true, thanks to the efficient coders at Asobo.
 

One thing my poor "old" RTX-2060 will never suffer from is too many FPS. If I could always get a locked 30 no matter where I went, I'd be extremely happy, and that's at 1080p. I agree with those who suggest anything over 60 is overkill for flight simming, but then how would I know? 😂

[Ricardo41 6,029]

11 hours ago, CarlosF said:

Why would anybody need more than 60fpm in a flight simulator.

I'm running MSFS on a 1440p monitor with all settings to high and am getting 30-50 fps even at complex airports.

Works for me. 

I stopped worrying about performance and frame rates a long time ago.

[virtuali 4,577]

15 hours ago, GSalden said:

Here in Europe most TV’s are 50 hertz. Because I wanted large displays I choose for Sony Bravia 4K 100 hertz TV’s. 

That would only be valid for live TV broadcast and/or PAL DVDs but, it has been many years that most of the TV sold in Europe are compatible with 60hz signals.

This happened already in the early 2000s, when European CRT TVs, when connected through Scart/RGB, could work in full color with US/JPN game consoles., and this was valid even for TV which weren't really fully multi-standard, thanks to the RGB Scart connection but, even back then, some TVs (usually from Sony, Panasonic, Toshiba) were truly multi-standard, so they could accept an NTSC signal even from Composite or S-Video.

When the HDMI came out, together with Blu-ray (BD are encoded in 24p, so they require either a TV that supports true 24p, or at least a TV that supports 60 hz so it could use 24->60 with pull-down), and then video streaming, there are virtually no TVs being made anymore that doesn't support 60hz.

I believe the "100 hz" indication in Sony TV can be a bit misleading, since it doesn't really refer to what input signals are accepted, but rather what kind of refresh rate the TV uses to add its own processing, since Sony refers to it as "Motionflow XR 800Hz (uncompressed 100Hz)", which is not very clear, but suggest it's something done at the last stage, to "smooth" motion, something you'd want to disable anyway in a flight sim, because it will surely add extra lag, it's like an additional "frame generation", made by TV, which I'm sure it's way slower than what the 4090 can do internally.

Edited July 7, 2023 by virtuali