Since I am usually rendering with the values:
Render to screen, broadcast, 1600 x 1200px and 600dpi
and because I am a real eco-system fetishist
my computer in the past often crashed because
it was out of free resources (RAM).

Today I normally follow this procedure to set RAM free:

1. I click all my wanted rendering options.
2. Then I save the vue-file and totally close down the program.
3. When the free resources were less than 50% I then really even restart my PC.
4. Then I re-open the vue-file that I want render via the recent files link and finally just click at the render button.

This procedure often helped a lot and bewares of the most hated reducing of the instances in the ecos or changing the atmosphere to a less complicated!

Best Regards,

Bernie

P.S. ;-)

Aye, folk have been doing such since Bryce days, it is a good tip :)
(or at least I used to, hey when you had 256 RAM....)

when you get, as I hope you do one day, a 64 bit system, such issues become less of an issue. Man, what a change!

Unless you intend printing your renders, there is no need for the 600dpi; for printing, 300dpi is ample. For a display of your image on the computer, just use the 72pixles per inch.

I want to make large poster prints of my images, that's the reason for the 600dpi.

;-)

Ah :)
I just work on a pure pixel basis since it's a direct conversion and you don't need ot worry about such things.

Divide your pixel size by required DPi to get inch sizes.
3000x3000 pixels = 10"x10" at 300 DPi.

A pixel literally = 1 "Dot" from DPi. It's the pixel size which is most important in digital images, because that is the true absolute resolution of it. Physicla size (inches etc) isn't important, only resolution is.
Where as DPi or equivalent is the resolution of film, or a canvas or whatever.

For big renders, you are as well doing a large-ish render, rather than an enormous one, minimum of 1600 or so IMHO, and use Photoshop or one of the good photoshop plugins for scaling up, "Genuine Fractals" or the like,

I have the trial version of Genuine Fractals on my art PC to test it, and it was actually good, I could see the way it was an improvement on scaling up that Photoshop can do. Bit pricey though so I'll need ot wait before buying that
http://www.ononesoftware.com/detail.php?prodLine_id=2.

I used Photoshop itself  to scale up some of my pics for printing out at 30" x 20" and they looked good :)

Quote "Ah :)
I just work on a pure pixel basis since it's a direct conversion and you don't need ot worry about such things."

Good idea Steven. BTW 600 dpi is completely unnecessary as the human eye can't see much, if any, improvement in detail above 300 dpi.  :-)

Large posters are often printed at 150dpi - the reason being, you are not viewing it close enough to see the slight loss of detail