HP claims the LaserJet Pro 100 Color MFP M175a can print at up to 16ppm for black pages and 4ppm for colour. Our 5-page black text document gave only 8.6ppm, but this rose to 12.8ppm on the 20-page test, so not that far off the stated figure.
However, colour pages suffered from the four-pass design of the print engine and gave only 3.5ppm which, while again quite close to the claim, isn’t very fast in comparison to other colour lasers, or even equivalent ink-jets, such as the £215 Epson Workforce Pro WP-4535DWF.
The print quality, as you'd expect from an HP laser engine, is very sharp. Text is clean cut and very well formed and lines and curves show no signs of jagged edges. Colour graphics are solid and bright, very eye-catching, and with no sign of any misalignment, due to the carousel design. Colour copies are also good, though with slight colour swings in black text, printed over colour. A photo print showed a reduced colour gamut, but there was usable detail in the hard-to-reproduce shadows.
HP quotes a noise level of 47dBA for the machine, but this must be measured from a long way away and possibly while the machine is idle. At half a metre, the distance we measure all desktop machines from, we heard peaks of 63dBA, considerably louder.
HP points out that black print costs on this printer are the same as on its equivalent mono machines. At 4.7p per ISO page, this may well be true, though it's still comparatively high. It's nowhere near as over the top as the colour cost, though, which at 19.0p including 0.7p for paper, is the second highest we've ever recorded. Do you really want to pay getting on for 20p for every colour page you print?
While the LaserJet Pro 100 Color MFP M175a is noticeably cheaper than some of the new LED-based multifunction machines, and quicker at printing black text pages, it's very slow at colour and costs more to run per ISO page than just about any colour printer we've tested. The print quality is fine, but we would be reluctant to pick this machine, unless the need for colour pages was very occasional.