devices · FM3 · reference · The grid and CPU
the grid and CPU
The model
Blocks in slots, joined by cables
Presets are built on a Layout Grid: a framework of slots you drop blocks into and wire together with cables. Every grid space and every cable is stereo, so there is no separate left and right path to maintain. Not every block processes in stereo.
Axe-Fx III Owner's ManualAn empty slot does not pass signal on its own. Where you need to bridge a gap, insert a shunt: a block whose only job is to pass audio through. A chain that looks connected but is silent is usually missing one.
Making room
Four ways to free CPU
the CPU meter sets the limit
Fractal publish a Preset CPU Limits chapter. Line 6 cap particular block types. Fractal let you build what fits and stop you when the processor is full, so watch the meter.
Axe-Fx III Owner's Manualchannels cost little, extra blocks cost more
Four channels inside one block cost far less than four blocks. If you are duplicating a block to get two settings, use channels instead. It is the biggest saving on the platform.
Axe-Fx III Owner's Manualcabs are cheaper than they used to be
Cab blocks and IRs are among the lighter blocks on modern firmware. Amp blocks and pitch effects are the expensive ones.
Fractal Audio Blocks GuideBypassed is not free
A bypassed block still occupies its grid slot and still costs processing. Remove what you are not using instead of switching it off.
Axe-Fx III Owner's Manual