[WOPR]

It doesn't matter what I print, or what Mac I use to do it, printing even the most simple of documents uses a huge amount of the CPU capacity. On my home iMac G4 it virtually always grabs 100% of the CPU just to print a basic document. I assume this is just a flaw of OS X, anyone know what causes it?

[OreoCookie]

What kind of printer do you have?

Cheap printers and pretty much all inkjet printers currently available use `host-based printing' which means the host (your computer) has to do all the math and then sends simple instructions to the printer (move print head from A to B, etc.). That will take a lot of resources, even if it just for a short time. Smarter printers use a printer description language, the most common ones are Postscript and PCL in their different versions. Here, the printer has to process the code (which is similar to a pdf file) by itself whereas the printer just converts the document into postscript for instance.

Hence it is not a flaw of OS X, but of host-based printing. On Windows, it's just the same. However, a print driver is an application like anything else, with bugs, etc. so without giving any details on the printer you use … it's kind of pointless to guess

Oh, and moving to peripherals … 

[WOPR]

The ones I use regularly are Canon inkjet printers, sorry I should have said that. I take your point though, they are just dumb boxes after all. Thanks for the info.

[OreoCookie]

Just one last bit of clarification: you will have the same effect with inkjet printers by HP, Epson and Lexmark (except for very few, e. g. some HP Business Inkjets).

Also, very often even `smart' printers offer a host-based printing options (e. g. Kyocera laser printers) since the host's cpu is almost surely faster than the cpu in the printer.

[I Bent My Wookiee]

I've always wondered the same thing. Thanks for explaining it to us.

[angelmb]

Never noticed that, I guess the 166 MHz RISC inside of my 'old' LaserJet 2100 TN is guilty here :-/ Could be it?… since there is no comparison between it (CPU inside LaserJet) and the much faster Mac CPU.

And how come inkjets lacking it?, just to avoid costs?… Has to be a pain be printing a good amount of paper and the process eating much needed CPU power… does your Mac become unresponsive?

Canon are the inkjets I like, yes, I really do.

[OreoCookie]

Originally Posted by angelmb

Never noticed that, I guess the 166 MHz RISC inside of my 'old' LaserJet 2100 TN is guilty here :-/ Could be it?… since there is no comparison between it (CPU inside LaserJet) and the much faster Mac CPU.

You can – in some cases – directly compare the cpus since they often use PowerPCs
In my department, we have just bought a LaserJet 4250 which has a 300 or 350 MHz PPC750CX cpu (aka G3 ) soldered on its mainboard. Which is faster than my first Mac (a 250 MHz G3 ). My printer at home (a Kyocera FS-1020D) has an embedded cpu, so a comparison to a computer's cpu is more difficult.

You are lucky that your printer has its own brain, since your Mac doesn't have to do that lifting then … all your Mac needs to do is create the Postscript code (since the LaserJet obviously speaks Postscript).

BTW, that's the reason why Postscript printers are sometimes slower than when host-based printing is used instead: the printer's cpu is usually a lot slower than that of your computer.

Originally Posted by angelmb

And how come inkjets lacking it?, just to avoid costs?… Has to be a pain be printing a good amount of paper and the process eating much needed CPU power… does your Mac become unresponsive?

It's to cut costs.
I have never noticed my Mac becoming unresponsive with OS X. There were a few examples (two I can think of with very complex postscript code) when my Mac was doing some number crunching, but never to the degree that it was unresponsive.

[angelmb]

Originally Posted by OreoCookie

… a lot of useful information …

Thank you very much OreoCookie… so in a nutshell, are there available inkjet models with an inner brain?… having in mind the high cost of the cartridges versus the printer cost I would rather expend some good bucks on a capable printer that not on a 'retarded' model

Talk about Dual CPUs computers being a great buy !

[Apfhex]

Probably if you buy a large expensive inkjet it will have its own processor. My school recently got some 13x19" capable HP 2800 inkjets that most certainly do their own processing (at 256 MHz with 96MB RAM and "HP PCL 6, HP PCL 5e, HP postscript level 3 emulation" according to HP's site)—and they're A** SLOW about it too. All the printers on campus I've used are like this actually. I've had to wait 15 minutes for a simple Illustrator document to print. Granted, these are not state-of-the-art printers.

My PowerBook has never slowed down from printing even large, complex documents. I just tell the app to print and leave it in the background and surf the web or something while it goes about its business, which usually doesn't take more than a minute.

[OreoCookie]

Well, there are only a few. HP's Business Inkjets (the new K550 and the older 2xxx line) do have its own `brains', the same goes for the not-so-popular Canon Business Inkjets.

There is an easy way of recognizing `smart' printers: they support printer description languages such as Postscript or some form of PCL.

Edit: I can confirm the observations about the Business Inkjet 2800 (with an older model, a 2280 TN): Postscript was sloooow. One of said super-complex documents took about 1.5 hours to process until I finally aborted the print job.

[Apfhex]

Originally Posted by OreoCookie

Well, there are only a few. HP's Business Inkjets (the new K550 and the older 2xxx line) do have its own `brains', the same goes for the not-so-popular Canon Business Inkjets.

Ah, right. I don't have much experience with large format inkjets and the only ones I've encountered had PS/PCL capabilities (a few different HP BusinessJets and an Epson 3000 or something like that, though maybe that one didn't). I wonder about Canon's new PIXMA 9000-9500 printers, the specs don't say much.

A point OreoCookie already mentioned: I wonder what kind of printer(s) the OP was using because maybe high-CPU usage was the result of crappy drivers. As I said I've no problem on my Mac with my Canon inkjet. I've used cheap Epson inkjets too.

For curiosity's sake I'm going to print an Illustrator document I've been working on. It has a bit of text, multiple layered objects with transparency, some gradient meshes, a gradient filling the background, and it's 2.5MB (in other words: nothing special, but not the simplest of documents either, in fact I think a PostScript printer would hate it ). Results: Illustrator took a maximum of 65% CPU while processing the document and PrintJobMgr then took a maximum of 55% CPU while printing. OS X remained totally responsive while this was happening.

[WOPR]

Re: what printer, I use an ip4000 at home and an S9000 at work, both do the same thing.