I'm currently trying to play the Mac version of Half-Life 2. My specs are: Processor: 2.5 GHz Intel Core i7 Memory: 16 GB 1600 MHz DDR3 Graphics: NVIDIA GeForce GT 750M 2048 MB There is a problem in the first chapter where you first enter the apartment blocks. The frame rate drops to a point where it is unplayable. All the parts up to this are fine and run smoothly. I tried at different resolutions, without AA, and without VSync, but still no luck. Other Source games like Day of Defeat: Source or Counter-Strike: Source run smoothly even at very high settings. I have no problem with Counter-Strike: Global Offensive at very high settings either. I tried redownloading Half-Life 2 and verifying the integrity of game cache, but this still occurs. Does anyone have a solution? Thanks.