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From: neff@hpvcfs1.HP.COM (Dave Neff)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Opinion sought on HP Deskjet Plus
Message-ID: <21990007@hpvcfs1.HP.COM>
Date: 9 Feb 90 21:48:01 GMT
References: <1990Feb5.225207.6913@wam.umd.edu>
Organization: Hewlett Packard, Vancouver, WA
Lines: 59

Regarding DeskJet+ graphics speed compared to the LaserJet IIP:

I think for all practical purposes both the LaserJet IIP and the DeskJet+
will print graphics faster than most all applications can generate
the graphics.  I did a couple of quick times, and will report them
below.  Basically, the DeskJet+ prints graphics as it comes in and
the print mechanism is the bottleneck.  The LaserJet IIP reads in the
graphics then prints the page, so the IO is the bottleneck.  In general,
the DeskJet+ has faster IO than the LaserJet IIP.  This means the
IIP will be faster if data compression modes are used.  The more
data compression reduces the IO, the faster the LaserJet IIP will go.
I dumped some files to both printers and here were the times I got.
I used the Centronics IO in both cases.  The times are to print a
single page.  A 16 Mhz PC was used in both cases so that the IO
was not the real bottleneck.

			    DeskJet+                LaserJet IIP
Mode 0 (uncompressed)
graphics (921012 bytes)     80 seconds              134 seconds

Mode 2 (compressed)         75 seconds              67 seconds
graphics (202236 bytes)


So there is no clear cut answer here.  But I think you will find
most applications take much longer than 1 minute to generate a
page of 300 DPI graphics "on the fly", so for all practical
purposes the DeskJet+ and LaserJet IIP will typically give comparable
graphics performance.  Note that the above numbers are a bit
unfair comparisons for the LaserJet IIP, since I printed a
single page.  When I dumped the Mode 2 (compressed) file twice,
the second page was done 45 seconds after the first page on the
IIP.  For the DeskJet+, each subsequent page will take the same
amount of time as the first.  In other words, the LaserJet IIP
numbers above reflect the first page startup time of typical
laser printers.

My basic point is this:  Don't expect laser printers to outperform
the DeskJet+ when printing 300 DPI graphics.  Laser printers will also
generally need extra RAM to do 300 DPI graphics (although higher 
priced printers may come with enough RAM standard).  Laser printers
will outperform the DeskJet+ in the area of text speed, but not graphics.

In my opinion, a major consideration of a laser printer versus a
DeskJet+ is the area of text printing volume.  The DeskJet+ is
rated at 50 pages per day.  If you generally print more than this
number of pages per day, your volume would suggest a laser printer
is more appropriate.  It also depends what you can afford.  But
if you print an average of 50 pages a day or less having your own
personal laser printer is probably overkill.  Of course, having a
laser printer is a status symbol too :-).  But graphics print speed
should not be a major consideration when comparing the printers.

Dave Neff
neff@hpvcfs1.HP.COM

Disclaimer: I am totally biased.  My personal printers are a DeskWriter
with a Macintosh and a DeskJet+ with a MS-DOS PC.  Although I have
access to shared laser printers I seldom use them.