Like most laser printers, the Oki C3400n is large. The gray-and-white unit stands 14.8 inches wide, 19 inches deep, and 11.4 inches tall, and it weighs a hefty 42.6 pounds. Hand wells on three sides make it easy to grip, but its bulky frame makes moving it a two-person job. The printer comes standard with a 200MHz PowerPC processor and 32MB of RAM, though you can upgrade to up to 288MB of RAM. Both Windows and Mac operating systems are supported, and the printer is Ethernet-ready, a boon for a multiuser environment. Duplexing (or double-sided printing), however, is a manual operation on this model, and Oki does not offer an optional duplexing unit for this printer.
The Oki C3400n suffers from limited paper-handling options. The pull-out paper cassette can hold only 250 sheets, and Oki doesn't offer an additional tray; if you print a lot, you'll find yourself constantly refilling the cassette. The cassette can accommodate paper up to legal length, but you can print sheets up to 35.4 inches long--for banner-style prints--using the single-sheet manual feed slot (hidden behind a fold-out panel). The top-mounted output tray is the default output area, but a door in the back of the printer allows for straight pass-through--convenient for heavier paper that can get stuck when bending through the roller mechanism.
The top of the printer opens to reveal four toner cartridges set in a straight-pass arrangement. Each can be pulled out and replaced individually. The standard black toner cartridge (1,500 sheets) costs about $40.75, while the high-capacity black cartridge (2,500 sheets) costs about $60. The standard-yield color toner cartridges (1,000 sheets) cost about $48.50, while the high-yield cartridges (2,000 sheets) cost about $87 each. Oki estimates printing costs to be about 2.7 cents per page for mono prints and about 16.7 cents per page for color prints, based on using high-capacity toner cartridges. The black print cost is about average for a printer in this price range, but the color cost is a bit high.
In terms of performance, the Oki C3400n impressed us with its fast print speeds. When printing black graphics and black text, it printed just slightly slower than the competition, including the Lexmark C500n and the Samsung CLP-510N: 16.01ppm and 15.55ppm, respectively. It knocked the competition out of the park, though, with its zippy color graphics and color text speeds: 11.92ppm and 8.38ppm, respectively. The only printer we've tested recently that beat these numbers was the C3400n's big (and more expensive) brother, the C5500n.