[Samba] Print speed with an HP Laserjet 4

[Kurt Pfeifle]

Mike Brodbelt <m.brodbelt at acu.ac.uk> wrote on Samba Digest:

> Fri May 2 12:53:56 GMT 2003
> 
> 
> I've also posted this message to the lprng list, but as I'm currently
> not sure where the problem lies, I'm posting it here too in the hope
> that someone has a clue.....
> 
> I have recently installed a printer accounting system on my systems, and
> changed the print model for some of my users. In most cases, this has
> been fine, but users who are using HP Laserjet 4 printers are
> experiencing significantly slower printing. The Laserjet 4 should be
> capable of producing 12 pages per minute, but is currently running at
> approximately 5-6 - each page is printed fully, and the printer pauses
> completely for a couple of seconds between pages.
> 
> The old print setup worked at full speed. This was users on NT
> workstations, printing via a locally installed HPLJ4 PCL driver, to a
> Samba provided LanManager printer port. Samba would pass the print job
> off to lprng, which would send it across the network to the printer on
> tcp/9100.
> 
> The new print setup, which is significantly slower, is that the user
> prints via a server based HPLJ4m PostScript driver,

"server based"? I assume by that you mean that the clients download and
install that driver via "Point'n'Print" ?  The *execution* of this driver
is always on the client (with Samba -- which can not execute Win32 printer
driver code on the server, in contrast to a Win NT/2k print server)

> to a spoolss samba
> printer port. Samba passes the job to lprng, which passes a copy of the
> PostScript file to my accounting system (printbill), and then sends the
> job to lprng, which converts the PostScript to PCL via the ifhp pcl_gs
> model, before finally sending it across the network to the printer on
> tcp/9100.
> 
> The server in a dual Athlon 2000+ with 1Gb RAM running Debian. I know
> there will be a slight processing overhead due to the PS->PCL
> conversion,

"Slight"? I think the overhead is considerable. Remember that printbill
does the "RIP"-ing procedure twice for every job -- once for the sending
to the printer, and once to generate the bitmap which is used to calculate
the toner or ink coverage (which is one parameter going into the "bill")-

> but I don't believe this is responsible for the slowdown.

If you "don't believe" -- why don't you set up a little benchmark
experiment?

Like this:

     * print to file on a Win Client using the "old" HPLJ4 PCL driver
       and save the PCL file
     * print to file on a Win Client using the "new" PS driver and save
       the PS file
     * print both files locally on your Samba server from an appropriate
       command line and benchmark the two print processes (with and without
       printbill activated)

This way you eliminate the Win --> Samba file transfer overhead as well
as you can estimate the respective printbill overhead.

I would be very much interested about your results.

> Whne this was first set up, the initial change was to upgrade the
> installed version of Samba, and move from LanManager type printers with
> locally installed drivers to spoolss printers with server configured
> drivers. Users are reporting that the problem has been present for a
> while, so it may well have coincided with that change,

I *believe* the main factor is print bill. (Did your migration to SPOOLSS
initially use the PCL drivers placed on the server, or PostScript drivers?)

> before I put the
> print accounting system and associated PS->PCL conversions in place.
> 
> I'd appreciate any suggestions as to what might be responsible for the
> speed change, and how I might go about fixing it. I'm currently at a
> loose end as to which part of the chain to suspect, and how to restore
> the speed...

Only a benchmarking of the two systems will help to answer this. I don't
have knowledge if anyone has done it before.

> Mike.
> 

Cheers,
Kurt