Colour vs monochrome performance

[Mike Khaw]

[Sorry to waste net bandwidth, I couldn't reach the sender in NZ]

>1) Does anyone have any measurements of the relative performance of colour
>vs. monochrome SPARCstations? I have some data which imply that on a
>colour 3/60, performance improves by a few percent (as much as 8% for the

I have one measurement on hand for a color 3/60, diskless, 8 Mb RAM, SunOS
4.0:

	1) suntools -n $options	# default gray background, see $options below
	2) open 1 shelltool
	3) swin -c		# set click to type
	4) cd /
	5) run a C program 100 times that executes the same code
	   as the "Redisplay All" root menu selection.

when $options =

	""		# use /dev/fb; i.e., menus in overlay bit plane
			# windows in 8-bit-deep color planes

		elapsed time = 29 sec

	"-8bit_color_only -toggle_enable"
			# use 8-bit deep color fb for everything

		elapsed time = 30+ sec

	"-overlay_enable -toggle_enable"
			# use 1-bit deep mono only

		elapsed time = 17 sec

In all 3 cases, CPU time = 0.4 user + 9.5 sys.

By way of comparison, a diskless 3/50, 8 Mb RAM, SunOS 3.2 (mono, of
course) did the same thing in:

	0.6 user + 11.0 sys. 18 sec elapsed time.

In other words, with a slower CPU, the 3/50 is faster than the color
frame buffer on the 3/60.

The reason is that the low-end (10-bit deep "cgfour") color frame buffer
is just dumb memory, so the CPU has to move all the bits around.  I don't
have the specs on the Sparcstation frame buffer, but it sounds like it's
just like the cgfour.

You could always try what I did on my 3/110: live in a mono desktop and
when you really need color, start up suntools -8bit_color_only and use
adjacentscreens or switcher to move between the 2 desktops.  Having 2
desktops didn't seem to slow things down noticeably, but then the 3/110
had a local 140 Mb shoebox with tons of swap space (a so-called
"dataless" configuration that had just /, minimal /usr and swap, and
got all user filesystems from NFS servers).

Mike Khaw
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