To assess instrument sensitivity in the absence of saturation, monoisotopic peak intensities were manually measured for 9 peptides across MsbA data generated on the SYNAPT and Cyclic IMS instruments and compared (Figure ). Here, all 9 peptides from 1-pass of the Cyclic IMS instrument exhibited intensity increases between 82-457% higher than their SYNAPT equivalents. This is consistent with previously published findings , and is likely a significant factor contributing to the observed increase in 1-pass cIM peptide identification. Relative to 1-pass, multi-pass cIM exhibited less exaggerated intensity increases (between 5-331%) when compared to their SYNAPT equivalents, with 1 peptide falling below. (Figure ). Whereas 1-pass improvement was more ubiquitous, intensity changes in multi-pass appear to be more peptide specific, which could be owing to the increased transmission path length for peptides that undergo a particularly high number of racetrack passes . Thus, it's possible that reduction of peptide ion intensities over multiple passes could contribute to the observed cIM underperformance.