Performance Issues and no GPU tracker (iMac)

Hi forum,

I’m having some trouble with my Unreal Engine development and finding out where the problem lies has been a little tricky for me. I made an AnswerHub topic about it here:
though I’ve had more luck posting my questions on the forum so I thought I might as well give it a shot here too.

I’ve detailed my problem thoroughly on the AH question, but here’s a summary anyway:

-I run an iMac - it has (to my knowledge) some pretty decent specs, except it has a crappy laptop-grade graphics card (oops)
-I experience some lag on a project that is literally as simple as “Build a small level 500x500 Unreal units with BSP brushes, add a BlueMan character, play”, which indicates to me that anything higher in complexity will make my framerate plummet dramatically.
-Trying to test my stats using the [FONT=Courier New]stat unit command as detailed here shows me that I run on average 22-23 FPS (46 ms per frame) when I maximise the window on my screen. However, I cannot discern where the bottleneck is (I expect GPU) since there is no ‘GPU’ statistic shown where there should be (according to that help article).
-And when I try to run the GPU Profiler with [FONT=Courier New]profileGPU, the window is empty and I see no statistics on my GPU load or usage.

My system specs are

  • iMac, 21.5-inch Late 2013
  • Processor: 3.1 GHz Intel Core i7 (I believe it’s a quad core)
  • Memory: 16 GB 1600 MHz DDR3
  • Graphics: NVIDIA GeForce GT 750M 1024 MB
  • Running OS X 10.9.5

I wish to resolve my lag or at least find out if my graphics card is indeed the one causing it (and running an iMac, then realise that I’m screwed because iMacs have non-upgradable graphics cards - sucks to be me I guess; shouldn’t have bought an iMac - I here ya).

Thank you very much for any help you can give me,

Or is there no real reason my setup shouldn’t be able to handle UE4 and should I look somewhere else than hardware to resolve this issue?

Your hardware actually isn’t bad, you have a more than capable CPU and while the GPU isn’t great, it’s much better than the integrated Intel stuff that most people have. If you’re running at the highest quality, then the performance is probably typical of what you’ll get. There’s things like Screen Space Reflections which can slow things down quite a bit along with motion blur and other stuff, so you might want to look into disabling those types of things. Also, if you’ve got the Retina screen then you’re running the engine at a higher resolution that what people typically run games, so be aware that might be an issue also.