RAW is data formatted exactly how the printer needs it. Depending on the printer concerned, it could be fully rendered to a dot-by-dot page image or, on more sophisticated printers, incorporate vector elements. A PostScript printer, for example, expects a page to be described by a set of PostScript commands. This is essentially a vector format and that's what the RAW data would contain.
EMF (Enhanced Metafile) describes the page in a vector format specific to Windows. EMF is actually a capture of the GDI (Graphics Device Interface) commands that programs use to tell Windows how to draw what you see on the output device, normally the screen. Because EMF is Windows' native image description language, capturing the commands into a spool file is a relatively quick and simple process. Immediately converting data to RAW format involves more processing and may produce a larger quantity of data than the equivalent EMF. Therefore, when printing from an application, EMF gets the immediate business of generating the print job over as soon as possible before returning control to the user.
When the print spooler is ready to send a buffered page to the printer, RAW data can be passed straight through whereas EMF commands must first be rendered into RAW format. This is done as a background process which means you can continue working. On a well-specified PC and/or printer, the effect on overall performance of this background processing may not be noticeable.
That's the theory, but it doesn't always hold true. And you would think print quality should be the same in either case, but I have avoided describing a lot of behind-the-scenes complications. Odd problems can sometimes be solved by switching from EMF to RAW, or occasionally vice-versa. In fact RAW is the manufacturer's preferred format for some printers. There isn't much you can do about the speed, but make sure the computer has enough memory to avoid excessive use of the swap file and ensure the disk is defragmented. You might also try the spool setting 'Print directly to the printer'. This is not an option when a printer is shared over a network. Your application will take longer to return control to you, but printing time may be reduced, because the job is not being spooled to disk.
I would also check the printer port settings in the BIOS. If it's set to SPP try the other settings, such as ECP or EPP, if available. With regard to the printing problem, have you looked for an updated driver on HP's website? If that doesn't cure the fault, try printing a diagram from another application. You could also try attaching another printer to the computer, and the original printer to another computer. The pattern of success and failure should show which component is at fault: the printer, its driver, Windows or the application.
Sakset fra:
http://www.pcplus.co.uk/tips/default.asp?pagetypeid=2&articleid=5367&subsectionid=390
