Hi, had a search around the forum but couldn't find anything on this topic. I'm experiencing very low frame rates (seems like about 2fps) in 3D games such as Ridge Racer 2 in SDLMAME, on Sierra 10.2.3. The 2D menu screens before the race work at full speed, but once into the actual race, performance is woeful. I've tried a bunch of versions of MAME (all 64 bit), with matching ROM sets. My old 0.153 SDLMAME / romset from 2014 works at full speed (with a little frameskipping), but I haven't found a newer version that does. What's weird is that the Windows version of 0.182 works fine on the same machine, even in Parallels! I'm using a dual 2.93GHz 2009 Mac Pro w/ 680GTX with a 1440p display, though have seen similar results on a 2012 Mac mini with a 2.5GHz i5 on 1080p TV. Emulators and front ends do seem to spray config files around in various places, so it's possible I've enabled some feature somewhere, sometime that's causing this performance issue, and I don't realise it's still enabled (e.g. V-Sync or something). There are no GLSL effects turned on. It occurs whether running straight MAME or via a front end such as QMC2. Could this be something to do with the SDL install? Is it worth uninstalling SDL and reinstalling it (not sure how to uninstall - just drag the framework to the Trash?)? Would running a 32bit version of MAME make a difference (one site seemed to think it was 'more compatible')? Does anyone know of any MAME-related feature that tanks 3D performance? I've tried everything I can think of, and am at a loss.