Below is a table showing the CPU usage of each block. There are a few things to keep in mind:

  • These values are only estimates.
  • The CPU meter changes quickly, so all % are within +/- 0.1% or so.
  • These values were calculated with no audio running through the FM3 and no USB cable connected. Real-time audio and processing does increase CPU a bit.
  • Values are calculated using the hardware CPU meter, not FM3-Edit.
  • All blocks are at Default Values for each type, unless noted in the Details column – endless combinations of values could change the CPU level.
  • Approximate “CPU Limit” per preset is 80%.

As mentioned, these are just estimates. Adding numbers together that may work based off this sheet may not work on the actual unit by a few % due to many factors of running real-time processing. Some numbers move extremely quickly, so “best guess” is used at times. Again, just estimates for a general idea of CPU usage.

Click here to see the FM3 and Axe-Fx III Block CPU estimates compared

CPU usage subject to change when firmware is updated


BlockDetails1.021.01Difference
Base CPU11.610.90.7
Shunt0.20.20
Input 1 & 2Classic Gate3.63.8-0.2
Intelligent Gate4.84.70.1
Noise Reducer4.8----
Out 1 & 2220
Amp1.92-0.1
Cab1 Cab3.63.40.2
2 Cabs3.83.70.1
ChorusDigital Mono5.95.60.3
Digital Stereo5.95.70.2
Analog Mono6.76.40.3
Analog Stereo6.76.40.3
Japan CE-26.76.50.2
Warm Stereo6.56.30.2
80's Style5.85.80
Triangle Chorus5.75.50.2
8-Voice Stereo10.810.80
Vintage Tape6.360.3
Dimension 16.15.80.3
Dimension 26.360.3
Dimension 36.36.10.2
4-Voice Analog8.17.80.3
8-Voice Analog11.611.40.2
Stereo Tri-Chorus5.55.40.1
Dual Chorus4.64.30.3
CompStudio Comp44.1-0.1
Pedal Comp 12.52.50
Pedal Comp 22.92.90
Dynamics Processor32.90.1
Optical Comp3.130.1
Tube Comp3.33.20.1
Analog Comp3.63.50.1
DynamiComp2.6----
DelayDigital Mono1.91.90
Digital Stereo1.91.90
Analog Mono220
Analog Stereo220
Mono Tape220
Stereo Tape220
Ping-Pong1.92-0.1
Dual Delay1.92-0.1
Reverse Delay1.92-0.1
Sweep Delay1.92-0.1
Ducking Delay1.92-0.1
Vintage Ditigal1.92-0.1
2290 w/ Mod1.92-0.1
Ambient Stereo1.92-0.1
Deluxe Mind Guy1.92-0.1
Mono BBD1.92-0.1
Stereo BBD1.92-0.1
Lo-Fi Tape1.92-0.1
Stereo Mind Guy2----
DriveBB Pre8.98.60.3
Bender Fuzz5.55.10.4
Bit Crusher6.35.90.4
Blackglass 7K5.85.40.4
Blues OD8.88.50.3
Esoteric ACB8.98.50.4
Esoteric RCB8.98.50.4
Eternal Love8.88.50.3
FAS Boost8.98.50.4
FAS LED-Drive8.78.50.2
FET Boost5.65.50.1
FET Preamp5.65.50.1
Face Fuzz6.260.2
Fat Rat8.98.80.1
Full OD8.78.60.1
Hard Fuzz5.45.10.3
Heartpedal 118.88.60.2
Jam Ray8.88.60.2
M-Zone Distortion9.39.10.2
Master Fuzz6.35.90.4
Micro Boost5.75.30.4
Mid Boost6.35.90.4
OD 2508.9----
Octave Distortion5.65.30.3
PI Fuzz6.35.80.5
Plus Distortion8.98.50.4
Rat Distortion8.98.50.4
Ruckus Ge8.98.60.3
Ruckus LED8.98.70.2
Ruckus LED/Si8.98.70.2
SDD Preamp5.75.40.3
Shimmer Drive6.46.20.2
Shred Distortion8.98.60.3
Super OD8.88.60.2
T808 Mod8.88.60.2
T808 OD8.88.60.2
Tape Distortion6.160.1
Timothy 18.78.60.1
Timothy 28.78.60.1
Tone of Kings8.78.60.1
Treble Boost6.15.80.3
Tube Drive 3-Knob5.85.60.2
Tube Drive 4-Knob5.85.60.2
Zen Master8.88.40.4
EnhancerModern3.63.50.1
Classic2.32.10.2
Stereoizer3.43.30.1
FilterAll TYPES except...2.320.3
FF Comb3.130.1
FB Comb3.13.10
Allpass2.3----
FlangerDigital Mono5.24.30.9
Digital Stereo5.34.40.9
Analog Mono5.45.30.1
Analog Stereo5.55.30.2
Thru-Zero64.61.4
Stereo Jet5.34.40.9
Zero Flanger5.44.60.8
Pop Flanger64.41.6
MXF-1177.8----
BBF-27.8----
Electric Mystery6.6----
Deluxe Mystery6.4----
D/AD 1857.5----
Manual Thru-Zero Flanger5.4----
Step Flanger6.3----
FAS Flanger5.3----
Formant2.42.5-0.1
GateClassic2.12.8-0.7
Downward Expander2.9----
GEQAll Types1.71.50.2
LooperSpeed Full4.54.7-0.2
Speed Half55.3-0.3
Megatap1 Tap4.13.60.5
10 Taps6.35.80.5
25 Taps9.89.30.5
45 Taps14.714.40.3
64 Taps19.419.10.3
MIDI0.20.3-0.1
Mixer1.61.60
Multiband Comp11.611.7-0.1
Multiplexer1.92.1-0.2
Multitap DelayQuad-Tap6.76.40.3
Quad Parallel8.88.50.3
Quad Series7.67.30.3
Diffusor6.36.10.2
Quad Tape9.38.90.4
Quad-Tap Band6.86.60.2
Parametric EQ2.22.3-0.1
PhaserDigital Mono3.13.2-0.1
Digital Stereo3.130.1
Script 452.52.50
Script 90330
Block 9033.1-0.1
Classic Vibe3.32.90.4
Stereo 8-Stage4.33.90.4
Barber Pole9.69.50.1
Stripe 903.1----
Naughty Rock3.7----
FAS Vibe3.4----
Treadle Phaser3.5----
Virtuoso Phaser3.5----
Borg Phaser3.1----
Ultra-Super-Mega Phaser5.1----
Mutated Twin-Phaser3.6----
PitchDual Detune8.99.3-0.4
Quad Detune14.615.2-0.6
Dual Shift9.810.2-0.4
Quad Shift1616.6-0.6
Dual Harmony10.310.7-0.4
Quad Harmony16.817.2-0.4
Classic Whammy7.37.4-0.1
Octave Divider4.74.8-0.1
Crystal Echoes7.57.20.3
Advanced Whammy6.67-0.4
Arpeggiator6.67-0.4
Custom Shifter10.511-0.5
Quad Shift Delay16.417.2-0.8
Quad Harmony Delay17.317.8-0.5
Virtual Capo6.67-0.4
Plex DelayPlex Delay9.89.20.6
Plex Detune15.714.80.9
Plex Shift15.614.80.8
Plex Verb13.5130.5
Shimmer Verb27.526.51
Resonator7.58.2-0.7
Return Block1.71.60.1
Reverb 
Normal, ED 8Ambience23.522.51
Asylum Hall26251
Cavern25.724.51.2
Chorus Hall26251
Cirrocumulus26251
Concert Hall26251
Cumulonimbus26251
Deep Chamber26251
Deep Space26251
Drum Room25.724.51.2
Gymnasium26251
Hallway25.424.21.2
Huge Room26251
Ice Castle26251
Large Cathedral26251
Large Chamber26251
Large Deep Hall26251
Large Hall26251
Large Plate26251
Large Room26251
Large Spring17.717.10.6
Large Tiled Room24.122.81.3
Large Wooden Room26251
London Plate25.724.51.2
Medium Cathedral26251
Medium Chamber24.122.81.3
Medium Hall26251
Medium Plate25.424.31.1
Medium Room25.724.51.2
Medium Spring17.517.10.4
Music Hall26251
Nimbostratus26251
North Church26251
Recording Studio A24.122.81.3
Recording Studio C24.122.81.3
Rich Hall26251
Small Cathedral25.724.51.2
Small Chamber26251
Small Hall26251
Small Plate25.123.81.3
Small Room23.722.51.2
Small Spring15.515.10.4
South Church26251
Stone Quarry25.724.51.2
Stratocumulus26251
Studio23.422.41
Sun Plate25.724.51.2
Symphony Hall26251
Tunnel25.724.51.2
Vocal Plate26251
Wide Hall26251
High, ED 8Ambience31.930.61.3
Asylum Hall34.533.11.4
Cavern34.132.71.4
Chorus Hall34.533.11.4
Cirrocumulus34.533.11.4
Concert Hall34.533.11.4
Cumulonimbus34.533.11.4
Deep Chamber34.533.11.4
Deep Space34.533.11.4
Drum Room34.132.71.4
Gymnasium34.533.11.4
Hallway33.732.31.4
Huge Room34.533.11.4
Ice Castle34.533.11.4
Large Cathedral34.533.11.4
Large Chamber34.533.11.4
Large Deep Hall34.533.11.4
Large Hall34.533.11.4
Large Plate34.533.11.4
Large Room34.533.11.4
Large Spring17.717.10.6
Large Tiled Room32.330.71.6
Large Wooden Room34.533.11.4
London Plate34.132.71.4
Medium Cathedral34.533.11.4
Medium Chamber32.330.71.6
Medium Hall34.533.11.4
Medium Plate33.732.61.1
Medium Room34.132.71.4
Medium Spring17.517.10.4
Music Hall34.533.11.4
Nimbostratus34.533.11.4
North Church34.533.11.4
Recording Studio A32.330.71.6
Recording Studio C32.330.71.6
Rich Hall34.533.11.4
Small Cathedral34.132.71.4
Small Chamber34.533.11.4
Small Hall34.533.11.4
Small Plate33.432.11.3
Small Room32.130.71.4
Small Spring15.515.10.4
South Church34.533.11.4
Stone Quarry34.132.71.4
Stratocumulus34.533.11.4
Studio32.130.51.6
Sun Plate34.132.71.4
Symphony Hall34.533.11.4
Tunnel34.132.71.4
Vocal Plate34.533.11.4
Wide Hall34.533.11.4
Ring ModClassic2.92.80.1
SSB Upper5.250.2
SSB Lower5.250.2
Rotary6.66.60
Send Block0.10.3-0.2
Synth1 Voice Triangle7.88.3-0.5
2 Voices Triangle1313.4-0.4
3 Voices Triangle1818.6-0.6
Ten-Tap DelayTen Tap Mono4.85.7-0.9
Rhythm Tap Mono4.95.8-0.9
Ten Tap Stereo7.68.3-0.7
Rhythm Tap Stereo7.88.5-0.7
TremoloTremolo2.92.60.3
Panner54.60.4
Bias Trem32.70.3
Harmonic Trem4.54.30.2
VolumeVolume2.11.90.2
Auto-Swell2.52.40.1
WahAll types3.13.10