To pick the top network laser printers, we test the devices' performance (i.e., speed), quality of printed output, features, and usability. We test and score each of these elements separately, and then we compute the overall score by assigning a weight to each element. For example, we assign weights in the overall performance category as follows: 40 percent for performance, 30 percent for quality, 15 percent for features, and 15 percent for usability. For the high-quality category, the weighting is 10 percent for performance, 70 percent for quality, 10 percent for features, and 10 percent for usability. In the Mac category, we use the same formula that we use for the best overall category. The only difference is that we use the EtherTalk rating for the performance score.
PERFORMANCE
We set each printer to poll the n
etwork as frequently as possible to ensure we get the most consistent times attainable. NSTL's performance tests measure how fast a printer can print text, graphics, and fonts. 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.
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 complex lines and filled areas. A second test produces curves and gray scales. An additional complex-graphics test, created in CorelDraw, includes gray-scale shading, lensing, and other complex images. This test stresses the printer's processor and RAM capabilities.
We also use the font test to measure the speed of a printer's processor. This test requires printers to create Times (serif)
and Helvetica (sans serif) fonts in regular and boldface in 30 different point sizes. We immediately repeat this test without resetting the printer to determine the unit's font-caching capabilities.
PRINT QUALITY
NSTL's print-quality tests measure a unit's ability to produce a photographic image; print attractive, legible text in a wide range of sizes; and draw lines. Because most laser printers produce monochrome-only output, color-print-quality tests are not included in this review. The line-squeeze test forces a printer to draw two lines increasingly closer together until the gap between them vanishes, which indicates the printer can no longer make the black-to-white-to-black transition. The test suite also gauges other print-quality considerations, such as how accurately the unit positions paper and how well it displays reversed (i.e., white-on-black) text and graphics.
OTHER FACTORS
Participating vendors supplied us with responses to a printer-fea
tures survey that included a wide range of questions about what emulations are supported, the printers' maximum horizontal and vertical resolutions, and what services are included with the standard warranty. We verified these responses and assigned a features score based on the most important features. We also evaluated how easy the printers are to use, based on such aspects as ease of ink-medium installation, intuitiveness of the control panel, ease of driver installation, ease of network setup, and clarity of the user's manuals.
CONFIGURATIONS
We tested all the printers in a network configuration using a Compaq Deskpro 66M network file server with 16 MB of RAM and Novell NetWare 3.12 installed on the hard drive. For a PC workstation, we used a Dell Dimension XPS P75 with 8 MB of RAM running DOS 6.22 and Windows for Workgroups 3.11. Our network file server used an NE3200 EISA Ethernet adapter; the workstation used an Intel PCI EtherExpress Pro/100 Ethernet adapter.
Each net
work adapter is bound to a variety of protocols to ensure it connects with each printer's network interface card (NIC). Our technicians tested printers with a Mac interface on a Quadra 640AV workstation with System 7.1, 16 MB of RAM, and EtherTalk installed. We tested each printer with the drivers that were supplied or recommended by its vendor. We disabled all print servers, spoolers, and buffers during performance testing.
On the PC platform, we used an NSTL-designed Windows applet to launch test files to each printer. After the last page of a test file dropped into the tray, a tester pressed Enter; the applet then displayed the number of seconds it took the printer to print the file. We used a similar applet to measure EtherTalk performance. On the PC platform, we tested printers in both PCL and PostScript emulations; on the Mac platform, we tested printers in PostScript only. Tests in both emulations were run with the printer set to its highest resolution.
Contributors
Michele Guy, Project Manager/NSTL,
has been testing hardware and software products for NSTL for the past four years.
Tarig Imbrahim, Tester/NSTL,
has been an independent network consultant for the past five years.
Jim Kane, Project Manager/NSTL,
has been testing network and PC hardware at NSTL for the past six years.
John McDonough, Technical Editor/NSTL,
has been writing for high-tech publications for several years.
Project Manager Jim Kane, Hard at Work
photo_link (23 Kbytes)
Using NSTL's network-printer-performance test-bed, project manager Jim Kane evaluates printer performance, quality, features, and ease of use.
How We Tested
