Samsung rates the machine at up to 33ppm, but the fastest speed we saw under test was 25.5ppm for our 20-page text document. The five-page document was slower at 14.3ppm and the machine takes around 20 seconds to wake up from sleep mode. In a typical office, you'll need to add that time onto most print jobs.
Duplex print is standard in this device and our 20-page document, printed as a 20-side, 10-page job took 1min 22secs – a speed of 14.6 sides per minute. This is a bit over half the speed we saw on the simplex document and is typical for laser printers of this type.
12 seconds for a single-page copy from the flatbed is good and a five-page copy through the ADF only took 21 seconds – this is a quick machine for copies. 15 x 10cm prints from a PC and a USB drive each took around a quarter of a minute.
Samsung’s spec sheet claims that duplex copying is also built-in, but this is not quite true. While the machine can read single-sided sheets from the ADF and print them as duplex pages, the scanner itself is only a simplex device, so you can't copy a duplex document to another duplex document.
Print quality is fine for text, with sharp, dense characters and no signs of unsightly artefacts. Greyscale graphics were marred by the darker tones applied to many greys taken from a colour original. It was quite difficult to read black text printed over some of them, where other mono lasers have done a lot better.
Text copying is fine, too, and as good as you're likely to get from a medium-range photocopier. When you try copying greyscale graphics or images, though, they're very likely to print out all-black. The default setting in the SCX-5635FN is for black text, but you can switch it to Text and Photos from the front panel.
The trouble is that although you do then get greyscales, they come through very dark and only copy lightness is directly adjustable. You can play around with the lightness of the images you print through software, of course, but in an office environment, you really just want it to do a good job on the default settings.
The only consumable for this machine is the single-piece drum and toner cartridge and using the high-capacity 10,000 page version gives a cost per page of 1.8p, including 0.7p the paper. This is very economical and is one of the main advantages of the machine.
The Samsung SCX-5635FN is a very workmanlike, office multifunction machine with good speed, low running costs and versatile operation. Its greyscale print quality is not all it could be, though, and it may take some fiddling to get photo images in printed pages looking good.