Wasn't it Chris Fieldhouse who wrote:
>Hi,
>
>I am trying out the Povray 3.6 beta 6 on 2 machine and I noticed an
>performance difference when rendering quite a complex scene (very large
>meshes involved).
>
>Machine 1)
>    Pentium II 333 MHz, Win98, 256M ram (Virtual memory 128M)
>Machine 2)
>    Pentium III 500 MHz, WinNT 4.0 sp6, 128M ram (Virtual memory 256M).
>
>The issue being that Machine 1, is much faster than Machine 2, even
>though M2 has the better and faster CPU. I know it could be the memory
>difference, but not such a performance degradation as observed. When
>rendering the same image the Win98 can render at 1280x1024 AA 0.3 and
>still beat the WinNT rendering at 800x600 AA 0.3.

On machine I, more of the POV memory space fits in the available real
memory (perhaps it all fits). On machine II, Windows has to swap bits of
POV in and out of virtual memory far more frequently because less of it
fits in real memory at any instant. If you watch your hard disk light,
you may see that your disk is constantly active on machine II. Disk
accesses are extremely slow compared to memory accesses, and the
rendering speed falls dramatically when there's a lot of swapping
required.

What are the speeds like if you render simple scenes that are small
enough to fit into the available memory of both machines?

-- 
Mike Williams
Gentleman of Leisure

Post a reply to this message