neff@hpvcfs1.HP.COM (Dave Neff) (05/11/89)
There has been various discussions about the relative performance of a DeskJet and DeskJet+ on the Mac. In order to set the record straight I did the following test. I copied the same mode 2 compressed file (about 202K of data) on my idle Unix system at 19.2K baud to a DeskJet and to a DeskJet+. This was printed at 300 DPI. For comparison I also include the times to print the same file on Centronics from an 8 megahertz PC. 19.2K baud Centronics DeskJet: 7 minutes 54 seconds 6 minutes 45 seconds. DeskJet+: 1 minute 53 seconds. 1 minute 13 seconds. Note that in the case of a Centronics interface a 1000K uncompressed graphics file would also be printed in about 1 minute 13 seconds but due to the IO limit the DeskJet+ would still take about 9 minutes at 19.2K baud serial. Conclusion: If your DeskJet printer driver can build 300 DPI compressed images in under 2 minutes a page the DeskJet+ should give much better performance than the DeskJet. One thing we have found, however, is due to the poor graphics performance of a DeskJet many drivers are "sloppy" and do not generate graphics very fast. Since the DeskJet was slow this did not really matter but due to the performance gains of the DeskJet+ many of these driver inefficiencies are becoming aparent. When comparing a DeskJet and a DeskJet+ on a Mac initially compare the performance difference on a Mac II with reasonable RAM (3 or 4 meg). If you are not getting under 2 minutes per page on the average with a DeskJet+ the driver is not optimal. Now 7 minutes per page on the average with a Deskjet is reasonable and typical. Once you have found the "best case" driver performance then measure a DeskJet relative to a DeskJet+ using your own system configuration. On a 1 meg Mac Plus it might take your driver 7 minutes to build a page so a DeskJet+ could be overkill, but then again you driver still might not be optimal. Dave Neff hpvcfs1!neff Disclaimer: This information is provided to clarify differences between the DeskJet and DeskJet+ printers. HP does not recommend nor officially support the use of the DeskJet family printers with Macintosh computers.