> What does "single-ported" mean, when talking about video cards or video
> memory?
That means that there is only one path into memory, and this path
is shared by the video signal generation hardware and the computer.
If the video signal generation hardware is grabbing something out
of memory (which is, for obvious reasons, a fairly frequent occurance
:-)) the computer has to wait for access.
Traditionally, high performance video cards used VRAM, which is
dual ported. That means that the memory system on the card has two
separate access paths, and can be satisfying a read request from
the video signal generation hardware at the same time as it's
satisfying a read or write request from the CPU.
I'm not sure what the latest trends are in video card RAM these days.
> With the Xpression in 24 or 32 bpp, the video performance could be a bit
> snappier, but is okay the way it is.
Well, you have to make sure you're testing the performance of the
card, and not the performance of your CPU. I'm not intimately
familiar with this stuff any more, but I would think a good card
test would be to check the speed of scrolling in an xterm (turn
off jump scroll) and to move an xterm around the screen with `move
windows while displaying interior contents' (in fvwm, this is the
OpaqueMove option) turned on. Both of these are very smooth on my
Matrox Millenium II. How fast Netscape can update its window appears
to be a bad test, or rather, a test of the CPU rather than the
graphics card.
For more speed, use 32 bpp rather than 24 bpp. I noticed a substantial
difference here on my P166. I used the `rubik' mode from xlockmore
as a quickie test.
Unfortunately, in 32-bit mode I don't think you're going to get
more than 1024x768 with only 4 MB of RAM. You should be able to
squeeze 1152x900 out of it, but that leaves basically no room at
all for font cache and the like, which would probably impair
performance fairly severely. With 8 MB of RAM you still have over
600K for font cache and whatnot in 1600x1200 mode. I also note that
21" monitors are getting pretty cheap these days; the Viewsonic
P815 is selling for under $2000 on the street.
cjs
Curt Sampson cjs@portal.ca Info at http://www.portal.ca/
Internet Portal Services, Inc. Through infinite mist, software reverberates
Vancouver, BC (604) 257-9400 In code possess'd of invisible folly.