Engine: 4.9.2-2707645
Operating System : Windows 10 Pro 64-bit (10.0, Build 10240)
Processor
Type : Intel Core 2 Duo CPU E8600 @ 3.33 GHz (2 CPUs)
Speed : 3333MHz
System Memory
Type : 2048MB Kingston @ 800Mhz (2 Planks)
Speed : 6400 MB/s
Display Device
Card : Sapphire Radeon HD 7850 1GB 256-bit
Driver : 15.200.1062.1003 (2015/07/28)
Preview window is work faster on the new hardware, but still not so fast as when any window is opened above unreal editor. Found that this is strongly associated with Use Less CPU when in Background option of the editor.