Speed increase Vs less colours?

[volvo_0ne]

Is there much of a speed increase using (say) 16 colour lowres as opposed to 32 colour lowres?

When using small (16x16) Bobs instead of sprites.

I don't seem to be able to fathom a way to calc the time (per vbl) left over to compare them, but no doubt someone will have a great idea for me

[idrougge]

Yes, there is much of a speed increase.

The old and proven way of measuring speed on the Amiga is to wait vbl, di your stuff, and then change the background colour. You can then look at the position where the colour is changed.

[Mrs Beanbag]

yes, as above... put this just before your Wait Vbl

doke $dff180,$ff0

the time taken to draw a bob will be proportional to the number of bitplanes: 32 colours = 5 bitplanes, 16 colours = 4 bitplanes.
it also depends on whether you are using autoback or not (3 blits vs 2, as well as some book-keeping overhead), or using a mask or not (although this latter should make a relatively small difference).

[Cylon]

Just try to add more and more bobs and you can easily compare when it starts to slow down.

So 16 colour bobs on 4planes vs. 32 colour bobs on 5planes.

[volvo_0ne]

Originally Posted by Mrs Beanbag

yes, as above... put this just before your Wait Vbl

doke $dff180,$ff0

the time taken to draw a bob will be proportional to the number of bitplanes: 32 colours = 5 bitplanes, 16 colours = 4 bitplanes.
it also depends on whether you are using autoback or not (3 blits vs 2, as well as some book-keeping overhead), or using a mask or not (although this latter should make a relatively small difference).

Autoback 1 does it for me (mostly)