BizHawk 1.7.0 beta
In addition to
opengl rendering, the next release will feature a new core. This time it will be quicknes.
No, this isn't a replacement for neshawk, but instead, this will be the first official "two cores of the same platform" situation in BizHawk.
Why quicknes? Because neshawk is rather slow (170fps for me in smb, on an i7 2600), and it would be nice to have a faster alternative. Quicknes is built to be fast as well as accurate as possible while still focusing on speed. It is more accurate than fceux generally (and passes more accuracy tests). As such, I felt like it was the best option for a lightweight nes core.
Quicknes however, does lack the robust mapper support of neshawk, but does emulate the vast majority of USA games (which is the bulk of the TASed games on tasvideos). The only notable game I know of that it fails to support is Punchout (sadly). For games that quicknes fails to support, a user will need to fall back to neshawk (or cases where more extreme accuracy is needed).
Core speed comparison: neshawk: ~170fps, quicknes: ~1550fps
Toggling the cores is done by config -> core selection
Which core is used is recording in movie files, and loading a movie file will automatically switch BizHawk to the appropriate core.