"Greg Copeland" wrote in message
news
On Tue, 20 Apr 2004 14:26:13 -0700, Peter Duniho wrote:
If your CPU and memory bandwidth is your bottleneck, a faster video card
will produce NO increase in speed whatsoever.

I have to call you on that one.

Really? I'm still waiting to see the post where you do.

Remember, newer video cards are able to
offload a lot of work from CPUs these day.

Older cards can too. That's the whole point of a 3D acceleration card. So?

If your video card is only a
generation or two back, it *can* make a big difference. Why? Well,
drivers are now able move the data the card and let the card compute and
figure out how to draw things.

Again, whole point, so?

This means, you now have more CPU available.

Only if the CPU is capable of preparing the data in time, and only if the
pathway from the data to the video card is not already running at maximum
speed. Are you sure you know what the word "bottleneck" means? You're
acting like you don't.

The net effect is that in some cases, it's like getting a
faster computer. Furthermore, if memory bandwidth is a bottleneck, it
might be because your computer is having to juggle large amounts of
textures bewteen its self and the video card.

So you're talking about more texture memory, not a faster video card.
Please go back and read what I wrote. My comment was specifically about the
card's processing speed, not its memory capacity. But even if it was, a
video card that's on par with a system only a year or two old is not going
to be running low on RAM for textures, not yet.

Again, a newer video card,
may greatly alleviate this. Why? Because a video card that is a year or
two old, especially if it's a commodity board, may only have 16M or 32M on
it.

You meant to write ONLY if it's a commodity board. No serious 3D
accelerator card has had only 32MB of video RAM for several years (5+). And
if it's a commodity board, then by definition it's not on par with the rest
of your year or two old system.

But boy, your straw man did sure fall over nice for you, I'll give you that
much.

Maybe 64M if it's a fairly nice one. These days, you can get a nice
mid-range card which is several generations more advanced, which have
128M, 256M and even 512M on them.

Name one mid-range card with 512MB of video memory.

This means all those textures which
were saturating your memory bandwidth and bus can now be loaded, ONCE,
onto your video card. That also means more main memory may suddenly be
available. If you were paging before and offloading the textures prevents
this, it can make a **HUGE** performance difference (of course, adding
memory would probably be recommended too). Again, this can result in new
life in a slightly older computer.

You sure are making a lot of new assumptions about the computer in question.
No decent game PC built in the last year or two is going to be running into
ANY paging issues playing games. Besides, if you ARE running into problems
like that, no simple video card upgrade is going to produce any significant
improvement in frame rates.

Because computers, video cards, drivers, and the 3d software which is
running greatly differs, it's impossible to answer in absoluetes what type
of return you'll get by moving up to a new card.

That depends on your absolute. I specifically limited my comment to the
situation where CPU and memory bandwidth are already the bottleneck. You
know, "bottleneck". As in, the place where performance is most limited,
leaving the other components at less than 100% utilization.

Sure, if you try to broaden your assumptions, you can't make an absolute
statement. But I didn't do that. You did.

Just the same, If you
are thinking of getting a new system, try a nice card first. You may find
that it gives you the extra life that you was wanting. If it falls short,
then you already have your video card for your new system. Nothing is
lost.

Of course something is lost. If you are considering high-end hardware (and
if you aren't, why are we talking about this at all?), then a new card is
going to put you out somewhere in the $200-400 range. But just because you
can afford a new card, that doesn't mean you can afford a whole new system.
So now you've just wasted $200-400 in sunk capital. Capital that's useless
to you until you've saved up the $1500-2500 you'll need for the current fast
hardware.

Tell you what. How about you send me four $100 bills. I will keep them
cozy for you, and I'll send them right back to you in six months. They'll
work just as well then as they do today. Nothing is lost. Right? That's
what you said.

Pete