Frame rate limits?

[asboyd]

Maybe it's the 1080 that is reporting the wrong rates (something in the GPU and firmware maybe). My son is O/S at present so cannot get hold of his 1080 to try it out.

Cheers,
Alex B

[evaamo]

Hi, Alex. Don't know about that... I haven't changed my hardware setup in 1 1/2 years, so I doubt the fps "loss" is related to a device or hardware configuration change. I even tried modifying my settings in the Nvidia panel to see if there's any chance - there isn't -  since Java uses the GPU's  "acceleration" to draw its graphics, regardless of you using OpenGL or not (in PSX's case it's Java2D).

Anyhow... 68fps in 4k is A LOT more than the 25fps I get using the FSLabs A320 in P3Dv4. 

cheers
-E

[Hardy Heinlin]

Maybe it's the 1080 that is reporting the wrong rates ...

The FPS indication in PSX is in the PSX code and indicates the truth. It's just a counter that is reset every 1000 ms. PSX's milliseconds stream comes from the PC's system clock.

The high speed thread in PSX is started whenever the last thread is finished and at least 14 ms have passed since the last start.


Cheers,

|-|ardy

[Phil Bunch]

I have updated all drivers and software etc. The only thing I have changed is the hdmi cable...
I know this is all trivial, I just can't understand what's causing it.

Perhaps you've identified something that is important in this context. 

The HDMI cables come in various versions, helping to manage copyrights, encryption, etc of the digital video stream.  My limited understanding is that an HDCP cable, used in an HDMI interface, is *not* a simple passive collection of copper wires but is instead an active electronic device.  There are several different versions of this cable design, each version probably having different internal electronics. 

Therefore I wonder if changing the video cable as you mentioned in your post might cause frame rate and other issues.  Maybe max frame rates require the latest version of the HDCP cable with at least some video cards under at least some circumstances.


Just a thought/suggestion.

I found the Wikipedia entry for HDCP cables to be a little helpful here. 

https://en.wikipedia.org/wiki/High-bandwidth_Digital_Content_Protection

[asboyd]

HDMI differences only come into effect if the cable run is longer than 2 metres. It is a bit like data network cables Cat 5 and Cat 6 only make a difference over long runs and at different rates. Most V1.2 V1.3 cables will carry 4K OK, also based on Hardy's email the frame rate is calculated before it leaves the video card.

Cheers,
AlexB

[Toga]

I've changed hdmi cables and it didnt't make any difference. All i can think of is a win 10 update or gpu driver update that's causing it as once upon a time it said 72.

[frenia]

Hello,

I have the exact same issue.  I left a question about it previously.  I used to get 72 FPS, then it dropped to 67 and stays fixed there.  Running Windows 10.  No big deal, just happened one day.

[Hardy Heinlin]

I think it's a feature in Java's economically optimized multitasking system.

PSX sets the time frame length to 14 ms. So the exact limit is 71.43 Hz, not 72.00 Hz. I guess in such busy time loops Java rather likes to add a fraction of a millisecond than to subtract it. E.g. with 14.7 ms the rate is 68 Hz. And that's just a difference of 700 nanoseconds.

I just tested it with 1 ms instead of 14 ms. Now I get 80 fps in takeoff position in full screen, and over 500 fps when reduced to 300 x 300 pixels. So it's clearly just a relative round-up effect in that 14 ms multitask "sleep" management, and not an absolute hard limit. I don't think a higher rate would make any sense aside from generating more heat in the box, and drawing power from other programs.

As far as I recall, the real EFIS screens get their high speed data updates via the ARINC busses at 50 Hz.


Regards,

|-|ardy


P.S.: When I set 13 ms, which corresponds to 76.92 Hz, I get max 73 FPS. Is anyone keen on that additional boost? I'm seeing no difference on the monitor.

[Jeroen Hoppenbrouwers]

Config option! Config option!

And then we will find a way to bypass your articifial arbitraty minimum and overclock PSX like real flight sim enthusiasts   :-D


Hoppie

[Will]

I'll upgrade my Mac to one of those water-cooled gaming rigs that looks like the creature's head from Alien...

[Hardy Heinlin]

48 and 72 fps frame rate limits are now re-tuned so that they won't be blocked at 47 and 69 fps -- in PSX 10.50:

http://aerowinx.com/board/index.php?topic=4191.0


|-|ardy

[Britjet]

Thanks Hardy - a solid 72 for me now!
Peter.