PERFORMANCE
Our nine speed tests measure each printer's ability to print documents with dense or sparse text, graphics, and fonts in a range of styles and sizes. The dense-text test requires printing a 2-KB file of ASCII text with little white space. Performance in this test correlates to raw speed, because there are no fonts or graphics for the printer to interpret. A second test document consists of ASCII text blocks broken up by areas of white space. Designed to simulate the printing of invoices and forms, this test is geared primarily to evaluating how fast dot-matrix printers can advance paper.
The graphics tests use bit-mapped images to simulate documents with custom fonts or screen shots. These tests help us determine how efficiently each printer communicates with a computer. One test measures the printer's ability to draw com
plex lines and filled areas. A second test concentrates on producing curves and gray scales.
We use the font test to measure the speed of the printer's processor. The test requires printers to create serif and sans serif fonts in regular and bold faces in 30 point sizes.
We generated a performance index for each printer by combining individual test scores with weightings that emphasized the tests that were most significant for an application category. For example, the results of the graphics tests counted for more of a color printer's overall speed score than did the results of the paper-handling test.
PRINT QUALITY
Our monochrome print-quality tests are PostScript-based tests that measure a printer's ability to produce a photographic image; print attractive, legible text in a wide range of sizes; and draw lines. For example, the line-squeeze test forces a printer to draw two lines successively closer together until the gap between them vanishes--indicating that the printer can no long
er make the black-to-white-to-black transition. The monochrome suite also gauges more esoteric features, such as how accurately the printer positions paper and how well the printer displays reversed (i.e., white-on-black) text and graphics.
The color-quality tests, also written in PostScript, in part stress a color printer's ability to print a wide range of hues and to blend hues (see the text box ``Color Quality'').
Although we wrote the monochrome and color tests in PostScript, we were able to test printers that don't support PostScript by using a custom Windows-based interpreter application that talks to the printer driver without any overhead that may be associated with commercial PostScript interpreters.
OTHER FACTORS
For each printer, we evaluated how easy it was to set up and configure the machine, load paper, and replace consumables. For individual application categories, we used the presence or absence of important features to determine whether a printer was eligible. For exam
ple, the CAD and DTP category considered only laser printers that can accommodate 11- by 17-inch paper.
CONFIGURATIONS
We disabled print servers, spoolers, and buffers during testing. We ran PC-based tests using Compaq Deskpro 66M (66-MHz) computers with DOS 6.0 and Windows 3.1. For Macintosh testing, we used Quadra 640AV computers with System 7.1.
This issue also includes printers from previous Lab Reports that are still on the market. We retested any non-PostScript versions of these printers so we could compare quality using our new interpreter.
Contributors
Alan Joch, Senior Editor/BYTE, coordinates the combined testing between the BYTE Lab and NSTL.
Jim Kane, Project Manager/NSTL, led the testing for this report. He has evaluated printers, systems, and peripherals for three years at NSTL.
Siva Kumar, Technical Analyst/NSTL, specializes in hardware and network-operating-system evaluations.
John McDonough, Technical Writer/NSTL, has covered the computer industr
y for seven years.
How We Tested
