Alarms Blaring, Lights Flashing... Argh!

Today can be summed up in twenty two little words - words that I have seen many times today, words that have caused me no end of frustration...

Yes, despite the fact that I originally spent close to a grand building a system specifically for the task of 3D rendering, I've been seeing nothing but this bloody out of memory error message all day. As soon as I click the render button, my computer grinds to a halt, the hard drive goes insane, memory and CPU usage shoot up to 100%, all other applications become unusable simply because they're so slow while the computer's trying to concentrate

So hey, I'm at some kind of impasse right now, I'm not sure where I can go from here. I'm sure as hell not going to reduce the image quality, or use less accurate/system intensive texturing, not after I've spent so long trying to make the thing as realistic as possible... so yeah, I'm stuck.

Which is akward, because the textures that I've produced for the meshes are pretty damn good quality, see for yourself at the bottom...

But yeah, I need to work around it, one way or another. I'm not putting the hours in then having my computer crying like a baby whenever anything goes wrong...