HP Laserjet 1300n: Postscript? PCL? too slow

Question

Hello,
I have a Laserjet 1300n (max memory, 80 MB) connected with USB 1.1 to my iMac 2.4 GHz.
If I print only text the printer is fast, no problems at all. As soon as an image or logo or any bitmap appears, the printer slows down, a lot: one minute per page (before starting the print) is easily reached and I have to wait often more.
How can that be? I read somewhere that CUPS rasterizes the data before sending it to the printer, but the iMac-processor used is almost nothing.
I also connected the printer to a netbook Celeron 900 MHz... it printed *instantly*. I was surprised and envy, of course.
Now I think the printer is getting the data in postscript format and maybe it takes too much for the internal processor to rasterize it, but how to change the mode in Snow Leopard? If CUPS can rasterize, SL should be able too. Where should I look for this setting? I found nothing.
As side question, I also wonder in which cases does the internal memory help speed: I maxed it because I got 64 MB for few euros, but not much changed. Maybe it helps only when using raster data, taking more memory than Postscript commands/data? I'm not an expert in this field.
Thank you in advance for the help.

Answer 1

Thanks, I didn't know about that driver.
I think that now everything gets rendered locally, since the printer queue shows a percentage increasing during the rendering.
I am still not 100% satisfied, since the gutenprint driver tops at 600 dpi while the PS driver can also go to 1200 dpi (I can see the difference) and the images are now too dark (the dithering technique changed, ordered patterns from PS reproduce grays more accurately, at expense of resolution), but I think this is the best I can get from the printer when connected to a Mac, so that's it.