Factors Influencing Speed
Intuition was never designed for opaque window movement or sizing, and
the fact that it can be done at all is a testimonial to its design and
flexibility. There are other window systems on the Amiga which can
provide faster opaque window movement than can Intuition; for example,
the EGS system bundled with many graphics cards does so. However,
Intuition can do a manageable job at this, especially on high end 68040
or 68060 systems with accelerated graphics cards such as the GVP
Spectrum or CyberVision 64.
There are several factors which can affect window dragging speed during
opaque movement:
- The largest factor is the speed of your hardware. Both CPU
speed and graphics speed are important. Standard amiga ECS or
AGA graphics are very slow in anything beyond 1 or 2 bitplanes,
but modern graphics cards are faster. A 68040 (good) or 68060
(better) helps as well.
- Generally, a 68060 is more important for opaque sizing than it
is for movement. Opaque sizing requires tremendous system
resources to recalculate the window contents with each mouse
movement event. This is not a task for lightweight systems.
The more complex the window, the more necessary a fast CPU is.
- Background pictures on workbench screens can be either slow or
fast on graphics cards, depending on the software you use,
whether you have installed any patches such as IPrefs2Fast, and
so on. Currently, MUI public screens may use background
bitmaps, although MUI redraws these faster for small patterns
than for large.
- The number of windows on the screen, and the degree to which
they overlap, affect refresh speeds. The more windows there
are, the slower window redraws are. Also, moving a window in
front of or behind another causes one or the other to be
redrawn, which causes delays. The impact of this is dependent
on the speed of your computer and graphics card. It isn't too
bad on a 68040 or 68060 system unless there are a lot of windows
open. It might be a lot slower on a 68030 or a system with a
slower graphics card.
- The depth of the screen makes a big difference on some Amigas.
On AGA Amigas, windows on deeper screens are updated slower than
on more shallow screens. With most graphics cards, 8 plane
screens are the fastest, while 16 and 24 bit are slower.
- Bigger windows are refreshed slower than small. This effect is
particularly noticeable for AGA screens, since the AGA blitter
is quite slow.
- Intuition moves smart-refresh windows in a manner which is not
optimal. Especially on accelerated graphics cards, these
windows are moved much slower than simple refresh windows. It
may be necessary to toggle off smart-refresh window opaque
movement to obtain reasonable speeds, or to use a patch such as
qlayers to speed this up.
- MUI can do very complicated things with window layout. It can
map different images to every button, region, and control in a
window. Doing this will of course slow down that window's
refresh speed. Generally, it is best to use either small
patterns, better still, solid colors for objects. See the
example windows in the User Interface
section of this document for a good looking MUI interface
that uses only solid colors.
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