The hitching in question seems to be related to shadow quality, or perhaps the way recent NVIDIA drivers handle shadows.
It is possible to eliminate all hitching by fiddling with shadow quality, either in game or via 'gr_init_dx11.lua'. I ended up altering the 'Medium' shadow quality preset in 'gr_init_dx11.lua'. This requires that you un/repack '~\Steam\SteamApps\common\MGS_TPP\master\0\00.dat' using MGSV_QAR_Tool. I settled on a shadow resolution somewhere between 'Medium' and 'High' but pushed the range scale ('CascadeShadowRangeScale' property) out further than 'Very High' to eliminate draw in.
So, these are the troubleshooting steps you should try, in order of effectiveness, if you're experiencing hitching:
- Lower shadow quality (also consider increasing the 'CascadeShadowRangeScale' property, which can be found in 'gr_init_dx11.lua')
- Disable/enable 'Shader Cache'
- Revert to NVIDIA GeForce driver v347.25
I thought to provide the solution to my question here. Apologies for the noobieness, but for me it was quite a steep learning curve :
- Diagnosis: I found out that when temperatures exceeded 90oC, the framerate drops. I used the freeware GPU temp to monitor my GPUs. The dedicated graphics card showed 0oC when not playing the game and I found out that the switchable graphics turns on the M7 dedicated GPU only when a full-screen application like a game is started.
- The problem: issue of the slowing was a drop in frame rate due to overheating.
- The solutions, in order of importance:
1) Cap the frame rate to 60 Hz (equal to the refresh rate of my monitor). In half life this can be done with fps_max [fps] in the console. I now use RivaTuner that comes tagged along with the freeware MSI afterburner to globally limit the framerate. Capping frames to the monitor's refresh rate doesn't impact gameplay. The gain in temperature is in the order of 10oC, likely due to the dynamic framerate of HL2 that peaks at rates exceeding 100 fps at times.
2) Disable HDR - I use a BenQ gaming monitor that also corrects for dark areas, and I see not much of a difference when turning high dynamic range off in HL2. Saves perhaps a few oC.
3) Lower water detail to simple reflections; I don't notice too much of a difference really and it saves quite a few oC when in watery environments.
4) Lower shadow detail to medium: may or may not help, but I do it anyway as it goes pretty much unnoticed, at least to me.
5) I replaced my mediocre laptop cooler with a Cooler Master Notepal XL. It features a fan airflow of 89.8 CFM, which is pretty good (as opposed to ~20 CFM of my previous cooler), However, the benefits of laptop coolers, other than raising the laptop from the bench, are disputed and so it's on the bottom of my list. I didn't check out whether it truly makes a difference. If any, it won't be much more than a degree or two.
My prime contributor to gameplay is texture details and that's left intact at very high.
In all, no loss in gameplay and a stable 75-85 oC with no drops in framerate.
Best Answer
In low settings, it is likely that graphical effects, and algorithms used for them are less demanding, to reduce the use of the GPU.
Because of that, it is possible that the CPU gets an extra pile of calculations in low settings. Mind you, probably much less complicated than the original ones going to the GPU, but still.
In your configuration, since the CPU is the bottleneck (being a bit old), it could explain this special case where the "low" preset is actually slowing your game down.
Now I'm only speculating, and talking about a general case. It might be caused by something else, for Fallout 3.