Use all cores in ue4 build

[ki11roy]

How to use all the cores in ue4 build? It seems that it uses only two by default:

12:57:00]	[Step 2/3] Reflection code generated for juydEditor in 15.2554895 seconds
[12:57:02]	[Step 2/3] Using Visual Studio 2017 14.16.27023 toolchain (C:\BuildTools\VC\Tools\MSVC\14.16.27023) and Windows 10.0.17763.0 SDK (C:\Program Files (x86)\Windows Kits\10).
[12:57:02]	[Step 2/3] Building 31 actions with 2 processes...

[adamrehn]

Under Windows hosts, process isolation mode will use all available CPU cores, whereas VMs spawned by Hyper-V isolation mode only have access to two CPU cores by default. Are you using process isolation mode or Hyper-V isolation mode?

[ki11roy]

Correct, I am in Hyper-V mode.

[adamrehn]

In that case the behaviour you're seeing is expected. For maximum performance I would recommend using process isolation mode if possible, since Hyper-V isolation mode suffers from a number of issues in addition to the CPU core limit that make it poorly suited to building large, complex container images such as those produced by ue4-docker. Process isolation mode will be used by default if you're running the latest version of ue4-docker with Docker 18.09 under Windows 10 version 1809 or newer.

[ki11roy]

Thanks!