On Gran Turismo 3 A-spec, I was driving on the Super Speedway circuit. I turned onto the main straight and the FPS dropped from perfect 60 to 40ish. As soon as I went round the next corner, the FPS went back to 60. Any ideas?
Specs:
CPU: Intel i5-8400H 2.8GHz
Graphics: Nvidia GTX1060
RAM: 16GB
Sounds like a straight up bottleneck. Does the EE or GS percentage reach 100% or very near when it slows? The Gran Turismo games are known to be hard hitters in a lot of places (though perfectly playable in others).
Are you using OpenGL hardware renderer? That should keep the fps at around 60 all the time since you have the same graphics card as me. I also have this game and it's totally fine, even when I race at graphic heavy courses like Special Stage Route 5 Wet and Monaco.
The GS percentage goes up to about 70-80 in cases, then straight back down to about 30. I also have this issue in GT4 on the Arcade Mode Car Selection menu (after manufacturer selection) the 3D rotating car model lags to around 30 FPS. Racing and viewing cars in the GT Mode doesn't change. I also get lag just before the race, during the countdown. I use the OpenGL hardware renderer at 4x native and 16x anisotropic filtering. I have changed settings both lower and higher- no dice. I am on a laptop though- does that change anything?
I haven't tried software mode, does that fix glitches?
Using a laptop really does changes a lot. Check GeForce Experience as it may have Battery Boost turned on. I got this issue until pandubz suggested this fix and it worked for me. Also, for me, I'm able to use the resolution up to 2x native so that too could be an issue and mine has 6GB of video memory.
Battery Boost would be a solid 30 FPS lock, at all times.
The GT4 arcade mode viewing thing does slow down a lot on underpowered GPUs, using OpenGL HW, if they are running too high of a Blending Unit Accuracy level. Higher internal resolution will only amplify this behavior. Best I can tell you are correct that this behavior isn't repeated ingame or in GT mode. As you've described it, it's pretty standard behavior, and I can't really suggest anything more than turn down Blending Unit Accuracy, or turn down internal resolution. OpenGL SW will look fine, but this puts all rendering work on to your CPU, and you will need several more CPU cores to run this reliably. An i5 may have trouble with this.
I have the Blending Accuracy at Partial and Internal Resolution at 2x and that did the trick for me.
OK, I'll try that gtgamer468. Cheers!
Software mode runs awesome but looks awful... I'm using 3x native right now. I'm not quite sure whether you'd class my 1060M with the 6-core i5-8400 as underpowered, but I'm new to this so ?
Geforce Experience is uninstalled.
Fixed! I simply turned off the Blending Accuracy and it works awesome with no visible frame drops. Thanks for your help!