Comparing 90Mhz Pentium to 60Mhz PowerPC???
Yasuo Ohgaki
: In article <1994Jul28.0...@sequent.com>, bo...@sequent.com (Nathan
: Boyd) wrote:
: > But what if I don't want the specific component that the manufacturer has
: > decided to put on the motherboard? What if after using the computer for a
: > year the owner wants to upgrade these components? With the Mac, you might
: > be buying what you don't want, or paying for something you don't use.
: Or paying for 3 dozen drivers you don't need every time you buy a piece of
: software or OS upgrade on a PC.
Aha. But PC's cards are cheap and have more functionality.
Could you buy S3 964 based video card with 2MB of vram at
less than $350 for your Mac? It also supports upto 4mb vram.
I think this video is fater than PowerMac's video.
(S3 964 is 64bit graphics card, in case you didn't know.)
: --
: Philip Machanick phi...@cs.wits.ac.za
: Department of Computer Science, University of the Witwatersrand
: 2050 Wits, South Africa (at University of Cape Town 4 July-7 Nov)
: phone 27(11)716-3309 fax 27(11)339-7965
--
Yasuo Ohgaki
e-mail: yoh...@diana.cair.du.edu
AFL GeneS
> Aha. But PC's cards are cheap and have more functionality. Could you buy
> S3 964 based video card with 2MB of vram at less than $350 for your Mac?
> It also supports upto 4mb vram. I think this video is fater than
> PowerMac's video. (S3 964 is 64bit graphics card, in case you didn't
> know.)
Where the PowerMac's VRAM video card has been tested against the WinTel
competition (Apple's new buzz word for the Intel/Windows world), the
PowerMac has come out ahead.
Peace,
Gene Steinberg
America Online Forum Leader, Macintosh Multimedia Forum
Author, "Using The Macintosh/Special Edition"
RISK
> Aha. But PC's cards are cheap and have more functionality.
> Could you buy S3 964 based video card with 2MB of vram at
> less than $350 for your Mac? It also supports upto 4mb vram.
> I think this video is fater than PowerMac's video.
> (S3 964 is 64bit graphics card, in case you didn't know.)
>
Agreed. But, not all cards work with all motherboard chipsets, and I've
proven that three or four times! I had purchased a Diamond Stealth Viper,
when it was the fastest thing on this earth and it turns out that it
wouldn't work witht the chipset on my motherboard. And the S3 964 is
64bits, but it runs on a 32 bit slot. BUT, all things considered it is a
little cheaper to get a 24 bit card for my PC than it is to get another
one for my Mac. Another thing though, most 24-bit Mac cards are using 3mb
or more. Compare fair! :)
RISK
valk...@mit.edu
: Aha. But PC's cards are cheap and have more functionality.
: Could you buy S3 964 based video card with 2MB of vram at
: less than $350 for your Mac? It also supports upto 4mb vram.
: I think this video is fater than PowerMac's video.
: (S3 964 is 64bit graphics card, in case you didn't know.)
Not quite. There is no way that a slot can compete with a CPU
bus. In the PC the VD is on board on its dedicated bus hardwired
to the processor. Any, even the fastest slots need a slot controller
to give them access. Then it depends on how many other slots are
occupied, for multiplexing (the more, the slower your drawing)
64 bits get waisted on a 32-bit bus. But in all fairness, for redraws/
updates of previously drawn windows, you don't need the CPU, it is all
in the VRAMs. So in these modes the S3 card may be faster. But when
new drawing takes place (you change smt in the image, rotate part,
crop, new image) no slot can compete with a hardwired bus.
Nicholas Valkanas
L.J. Wischik
>.... But when
>new drawing takes place (you change smt in the image, rotate part,
>crop, new image) no slot can compete with a hardwired bus.
This is foolish.
How, you asked, can a card be faster than a hardwired bus for drawing?
Typically, CAD programs and graphical operating systems use high-level
graphics commands such as 'Draw Window Frame' or 'Draw and fill
triangle' or 'Render Text'. If the accelerator card has these functions
built in to it, it can generally perform them very quickly (since it is
optimised for this sort of thing). However, if the CPU had to do them all
it would have to take lots of time rendering each pixel individually. In
this way, accelerator cards can be a lot faster than not having an
accelerator card for lots of operations - drawing, scrolling, dragging
windows &c. This list includes image generation as well as dragging and
bitblting.
No slot, you said, can compete with a hardwired bus.
What is a hardwired bus? What is a slot? All buses are hardwired. The
main critical factor is the number and distribution of buses. A mainframe
has lots of buses for i/o: this is its distinguishing feature, and it
makes i/o with lots of terminals much much quicker. A workstation has
fewer buses; a personal computer will often have less. A PC has three
datapaths: a very fast one for CPU to memory; an almost-as-fast between CPU,
RAM, video and hard disk; and a slower one for general slots.
If by 'hardwired bus' you meant 'a place on the board which is
permanantly fixed and assigned to that particular device', it is no
longer a bus - is it. That is, if it just has one device on it, it is not
a bus. If there are a number of things (ram, video &c) which share a
common datapath, then it is a bus. I think the PC solution of dedicating
one bus to extremely fast things - ram, video, hdisk - is an emminently
sensible one.
--
Lucian Wischik, Queens' College, U of Cambridge. ljw...@cus.cam.ac.uk