The last few builds (including 982) I've been turning Sim Processor Thresh on just because multi-threaded physics sounds cool and why not? I haven't had any problems and I can't really tell any difference between on and off. Is there any advantage to having it on? Any disadvantage?
I've set my Threshold to 1, 2, 3 and 4, and the simulator automatically restore the PLR file to "3". In all cases I have horrible results, so I left it "255", no need to chance it for me (4970K btw)
I used it a few weeks with 946, but encountered problems with task switching (ALT & TAB). So i took it off again. Maybe i give it a go with 982 now.
It didn't make any difference for me. Haven't benchmarked build 982 yet. [Hah! Have done very little with build 982 yet, other than install and confirm I could drive.]
255 is default and means rf2 uses 2 threads, value 3 equals the multithreaded physics that were enabled in build 930 and caused lots of people issues. I think the potential advantage was mainly on old quad-core CPU's that fell out of realtime sometimes with many AI.
I was in a league race last night and starting toward the back of the grid with 34 opponents, I dropped graphic settings to cope with such a large field and my FPS stayed above 60. However when any opponent car was in close proximity, I had terrible jitters/stutter from their cars, not lag or warping but something else. Once they were 10+ meters away the stutter stopped, It ruined my enjoyment tbh. I have a QuadCore AMD A10 7700K Black Edition 3.4GHz Socket FM2+ APU 4MB Cache cpu. So this morning I decided to try some stuff in single player. I changed the Sim Processor Threshold to 3, capped my frames in the .json to 60 and vsynced to the GPU ( amd R9 ) Now can anyone confirm running with AI puts far more strain on the CPU than running with Human opponents ??? Because with those changes I could run with 29 AI from the same position on the grid as last night, with higher graphical settings, without any stutters/jitters or problems. I can't bring up the fps or cpu widget in sim ( ctrl-f ctrl-c ) because my bezel correction with eyefinity hides them. The next league race is in 2 weeks so I hope that one will be smooth with those changes, if not can I put it down to lag.
Yes, sure and absolutely logical that AI eats CPU-power! Human physics online is calculated at the clients machine, while with AI your machine has to compute your physics and AI-physics and AI behaviour.
Thanks Peterchen, So in my tests I can run 29 AI without issue, I should easily be able to run with 30 Humans and use less cpu power, not taking into account lag.
My un-scientific testing with Fraps tells me that sim processor thresh ON = 7-10 more fps on my machine. Also, pre-rendered frames set to default in control panel gives me more fps than if it's set to 1. Your mileage may vary.
I dunno. There were multiple threads around here that setting it to "1" reduced stutters and gave more fps. Never bothered to test it until now. Leaving it to "game controlled" in the nV control panel gives me slightly more fps.
Due to the limited info provided by ISI on this option, I'll ask here. Is this option only usable on processors with hyperthreading enabled? I have a 2500K which does not have hyperthreading, so will it be pointless for me to enable it? And why the values 255(off) and 3(on)? Why not 0 for off and 1 for on, or true/false? Struggling to find the logic of using 255 and 3.
Because the description say something like :" set number of processors avaiable to allow ... setting 3 you are saying : IF number of processors > 3 (quadcore) THEN... Setting 255 is a way to be sure to never meet the TRUE condition.
Not directly related to hyperthreading, unless you had a dual core with HT (?). But I doubt enabling it would be a good idea anyway. I would suggest the value is the decimal representation of a bitmask. 3 = 00000011, so 'on' for two cores only. 255 = 11111111, so 'on' for all cores. My guess (which might actually be backwards for the current logic... ah well)
Apparently someone had huge problems having it off in one of my leagues. And others who followed his advice to turn it on seem to have had good results to turn it on as well. So I'm guessing you mean leaving it off would be a bad idea? It is a weird one, I guess what Comante said may be the most logical explanation.