DFBonnett said:
I have an older frankenputer with an AGP 8x slot and regular PCI
slots. Currently am using 32 meg Matrox G450 (AGP 4X?). Video does
not stream well (choppy) and I am wondering if an upgrade to an 8X
card with more memory would be worthwhile or if there is a system
tweak I could do. Currently, 1.7ghz processor, 1 gig ram, XP SP3.
Any guidance would be most appreciated.
In Task Manager, is your CPU graph pegged at 100% ?
Maybe you're out of processing power.
That can happen, if every aspect of the movie playback is
being done by the CPU, the choppiness could be due to CPU power.
*******
Video cards do provide some assistance in movie playback. A relatively
old support, was IDCT (inverse discrete cosine transform). Fast forward
12 years or more, and video cards now can almost completely play the
movie on their own (for a limited set of movie standard formats).
http://en.wikipedia.org/wiki/IDCT (old, and in some cases now, no longer used)
http://en.wikipedia.org/wiki/Purevideo (new, Nvidia)
http://en.wikipedia.org/wiki/Unified_Video_Decoder (new, ATI)
You could experiment with an HD 4350 or 4650, which would have UVD 2.2.
I don't know if anything more modern than that is offered for sale now.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161318
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125281
The biggest weakness on cards like that, is the state of the
drivers. AGP drivers don't get much design effort put into them.
*Always* read the customer review section on sites like Newegg, before
you buy a card like that. Sometimes, a customer finds a driver that
works well, and that makes all the difference in the world.
Note that, many modern GPUs are PCI Express, and bridge chips are
used to convert them to other slot formats. In the process, the
driver writers may choose to remove some features from the driver.
If a modern card had a PCI connector (133MB/sec), the driver may
remove 3:2 pulldown and telecine (whatever that is), only on the
PCI card, while leaving the features enabled on the same GPU when
the slot type is PCI Express x16. So that's a slight gotcha that
requires a bit of work to trace down. Again, the reviewers may notice
some of these things being different than on the PCI Express version.
So it's a gamble going with another video card. If you get
a working driver with the new card, plus have a movie player
application that uses the new features (perhaps via DXVA interface),
you might get movie playback with less CPU loading. Some movie
player programs, even have ATI or Nvidia specific code to handle
the acceleration features.
http://en.wikipedia.org/wiki/DXVA
To give an example of what a difference the features can make,
I tried full screen Flash movie playback on my old P4 system.
Flipping from regular window to full screen, would push the processor
to 30% usage or higher. Apparently, all the CPU power was being used
to scale the image to fill 1280x1024 pixels. (The video card in that
case, was obviously missing a scaler in the GPU.)
By using another video card, which had hardware scaling, the CPU usage
dropped back down into the noise (5%-10% or so). In that case, the
regular sized window was put into offscreen memory on the video card,
and the GPU scaled up the image before placing it onscreen.
A modern card raises these possibilities, but whether they're realized
or not, relies on more than one piece of software to achieve.
I've had unexplained "glitches" in video before, where the
AGP slot worked fast enough, the card had enough memory, and
I couldn't fix it. And on another motherboard, things might be
smooth. Whether it was a driver issue, or a hardware design problem,
or even bad application code, I couldn't figure it out. I tried
adjusting all sorts of controls to change it. That's all part of
the fun.
*******
When installing the new video card, the sequence is
1) Remove Natrox video driver via Add/Remove (very important).
I learned this the hard way with respect to Matrox driver.
2) Shut down, unplug, change out video card.
3) Install new ATI AGP card (good Nvidia bridged cards are no longer made).
(You can get Nvidia 6200, but that likely won't have as many movie playback
features built-in.)
4) Make sure you've hunted down the "best" ATI driver known of.
Now, install that driver, using instructions provided by other
users of the card.
5) Voila... Maybe. It's a $75 spin of the hardware roulette wheel.
Paul
