Laser Printers Guide

Oki B840dn review

Oki B840dn A3 Mono LED Printer - The Speed of Light

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Overall rating 9/10
Very fast print speed
Good print quality
Good expandability options
Driver installation process can be better




Speed Test

The Oki B840dn starts up very quickly from a power-off state; in our tests, it took about 20 seconds to be ready to print. First-page-out timing (we define this as from the time we hit the print button on the computer to the time the printout landed on the output tray) was just a hair over 10 seconds. 

Print speeds for a 10-page A4 black-and-white (B&W) Word document and a 10-page A3 document took just 24 and 36 seconds to print respectively. We calculated the print rates to be about 41 and 23ppm (pages per minute) – slightly exceeding Oki's own claims of 40 and 22ppm. Of course, Oki’s testing methodology is different from ours; but in a nutshell, we've proved that the B840dn is a very speedy printer.

On the other hand, duplex speeds are measured to be about 32ppm (A4) and 17ppm (A3).


Image Quality

Below are crops of the Oki B840dn's document print outputs at various resolutions. The font used was Arial at size 12.


Overall, we would rate the Oki B840dn's text print quality as excellent; it's dark, full-bodied, and crisp - even for small font sizes. At an arm's length, it's hard to discern the difference between 300dpi and 600dpi (what you're seeing here has already been blown up several times). If we were to nitpick, it'd be that at 300dpi, under close observation, diagonal lines exhibited a stair-like effect.

The difference in resolution is more obvious when we scrutinizes print quality for graphics. Unsurprisingly, at 300dpi, print dots are more apparent due to the increased amount of space between each dot. Checking the Toner Save option made little difference to print quality, though it did render the page a shade lighter.

In normal (600dpi) print mode, mono reproductions from color originals showed very little banding. Our test photos turned out reasonably well too, though with some loss of details in shadow areas. Dot pattern, while present, was hardly noticeable; it got better when we moved up to 1200dpi. Even at the highest resolution, there isn’t much of an impact on print speed.

Overall Quality Scores - A Subset of Performance Ratings
Criteria Score (out of 10)
Text Prints 9.0
Graphics Prints 8.0
Photo Prints 7.5