ER-301/CPU Load

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Revision as of 03:25, 1 May 2019 by Odevices (talk | contribs) (Actual Measurements)

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CPU Load

You can query the CPU load at any time from the admin menu.



CPU load will usually be the sum of the fixed costs of all units in use (plus ~3% of overhead). A unit’s cost does not depend on where you insert it except to the extent that mono vs stereo might affect it. In general expect, a stereo unit's cost to be from 50% to 100% more than its mono version. The number of (local and global) connections does not matter.


In general, units are designed to have a fixed CPU cost that does not depend on their inputs. The cases where this is violated (in order of severity) are:

  • Manual Grains: CPU load grows as more grains are overlapping (i.e. polyphony). This happens when you trigger grain production faster and/or increase grain duration.
  • All random-access sample playing units and delay units with a speed control: L1/L2 cache misses caused by non-sequential access to sample memory will result in increased CPU load (stalling). Layman translation: Randomly jumping around in the buffer at audio rates, or playback at really high speeds (>10x). This forces the ER-301 to repeatedly query the RAM (slow) for necessary data because it is not in the L1/L2 memory cache (fastest).

Actual Measurements

Forum user a773 has compiled this listing of CPU load measurements for a selection of units: a773's Unit CPU Load measurements