Meta: MTVU compatibility issues #1669 - PCSX2/pcsx2 - GitHub 20 Nov 2016 —
When MTVU was introduced, it changed the hardware requirements for emulation overnight.
The term "upd" likely refers to the significant updates made to how MTVU functions in recent Nightly builds
Normally, VU1 emulation runs on the same thread as the main CPU emulation, creating a bottleneck.
Always download the latest nightly/dev builds rather than outdated stable releases.