I have rendered at over 8000 px before, so I'm sure it goes higher than HDTV...

I'm not aware of a maximum pixel output, but I imagine that at a certain point, without a render farm to push work out to, your computer will not be able to handle the render.

I'm sure there is, but so far I've only hit against physical processing resource limits (whereupon most renderers just shot down and crash you out). I thought raytracing has a maximal depth theshhold, although I have no idea what it is.

what kinda processor are you guys using?

Quad Core (Max is multi-threaded and can utilize all cores), 2.8 GHz, 6 GB ram, 64 bit, GTX 260 video

its not an alienware is it?

I'd imagine that the hardware, like loremipsum mentions, would define the upper limits of image size. If you've got a powerful machine, rock and roll.

What are going to be doing with the image? Printing it? Displaying it on a large-format screen?

It's basically an OS and memory limitation.

If you have a 64-bit OS, then it is pretty high. I've run 16000 pixel wide renderings with 6 gigs ram before.

Before I upgraded and was using XP (32-bit), I could do 8000 pixels, with 4 gigs ram (of which 3.25 was actually usable).

mostly just curiosity
I usually only render to HDTV with 1920 x 1080