On the PC, we ran tests at each printer's highest resolution and at the lowest resolution available in each category. Whenever possible, we also tested the printers on the Macintosh platform.
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, since there are no fonts or graphics for the printer to interpret. A second text 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 simul
ate documents with custom fonts or screen shots. These tests help us determine how efficiently each printer communicates with a computer. One test component measures the printer's ability to draw complex 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 different 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
This month we introduce the second version of our monochrome print-quality tests. As in past reports, these PostScript-based tests measure a printer's ability to re
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 longer 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, stress a color printer's ability to print a wide range of hues and to blend hues. Other parts of the test examine ink placement: the ability of the printer to accurately place lines without misregistration or smearing.
Although we wrote the monochrome and color tests in PostScript, we were able to test printers that don't support PostScript by using Freedom of Press, a PostScript interpreter from ColorAge that translates PostScript i
nto low-level printer driver calls.
FEATURES AND EASE OF USE
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 example, the CAD and DTP category considered only laser printers that could accommodate 11- by 17-inch paper.
THE TEST CONFIGURATION
Our printer benchmarks are applications that run under Windows 3.1 or Apple's System 7. We disabled print servers, spoolers, and buffers during testing. We required workgroup lasers to have at least 8 MB of RAM and PostScript, if available. Other lasers had at least 4 MB of RAM and PostScript, if available.
We ran PC-based tests using Compaq Deskpro 66M (66-MHz) computers with 540-MB hard drives, 8 MB of RAM, and DOS 6.0 and Windows 3.1. For Macintosh testing, we used Quadra 640AV computers with System 7.1, 16 MB of RAM, and 400-M
B hard drives.
Test data for this report cannot be directly compared to previous printer Lab Reports. In addition to running a new version of our quality tests, we upgraded our PC test-bed for this report (for previous reports, we used 33-MHz Compaq systems to run our tests).
This month's test sample focuses on printers for high-end business and professional applications. We selected only high-end dot-matrix printers; we think this is the most important niche for this technology. We tested all available new models of laser and ink-jet printers, but we didn't retest models that received low speed scores in previous reports.
Contributors
Scott Higgs, Project Manager/NSTL, has tested hardware for NSTL for six years. He spent last year in Europe, where he helped establish a testing facility in France.
Alan Joch, Senior Editor/BYTE, coordinates the combined testing between the BYTE Lab and NSTL.
Chandrika Mysore, Printer Report Project Manager/NSTL, manages evaluations of printers,
systems, and peripherals.
Morgan Nec, Consultant/NSTL, has tested printers and systems for NSTL since 1988.
Photograph: The evaluation team: Seated, from left: Chandrika Mysore, Scott Higgs; standing, from left: Alan Joch, Morgan Nec.
How We Tested
