As a Mac user I do not usually worry about things like drivers, but recently I took an interest after experiencing issues with my discrete graphic card.
Most of the time I use my computer for non graphically intensive tasks, but have noticed that for some time my machine appears to run hot, and this tends to happen when I launch an application that takes advatage of the discrete gpu. For some time I suspected something is not right, but a recent bench mark test on geekbench confirmed my suspicions after returned a rather surprising 0 benchmark result, with depth of field returning 0 on the detailed results. As it did not appear to be failing completely I decided to investigate further.
After some investigation I could see that the Geforce driver was installed, but it also looked quite dated. I had recently updated my Mac to Mac OS Mojave and this had a later version of the drivers installed. Also, there are still no response for Nvidia drivers, and the ones showing installed were compatible with mac os 10.13 only. Apparently there are issues with Nvidia supporting drivers on Mojave as Apple is looking for them to support metal with native support for CUDA being dropped. There is quite a long thread discussing the issue on Nvidia website and there does not appear any date when this issue will be addressed, much to the dismay of all those with Nvidia card owners. Hence for the purposes of this exercise I decided to downgrade to High Sierra, so I could at least try installing the Nvidia driver.
The first Nvidia driver I tried failed, however it did give me my Apples OS Build number which I was able use to to search for and download the correct driver. Upon install and restart I was then able to run the bench mark tests again, and low and behold get a decent opencl score, nearly 3 times better than the integrated IntelmHD4000 gpu. Not only that but I was able to run Fortnite albeit with the graphics turned down, something more or less impossible previously.