UDK 32bit slow D3DCREATE_MULTITHREADED
I always run the 64bit udk build because I have never had a reason to ever run the 32bit build before but today I accidently ran the 32bit bit build and it was running very very sluggish. So to make a long story short I found that d3d9 is throwing a warning and spamming it to the output window which is why its running so slow:
Direct3D9: (WARN): Device that was created without D3DCREATE_MULTITHREADED is being used by a thread other than the creation thread.
This problem does NOT happen with the 64bit version.
ATI Radeon HD 5700 - latest drivers.
Intel Core 2 Quad CPU Q8300
Probably it's not because of this but, do you have directX in debug mode?
For that you need to have the DirectX SDK installed, and check if the DirectX Control Panel is in debug mode.