General advice on improving my HTPC?

[n64man120]

I put together a Home Theater PC last summer, however now I'm looking into getting the best performance out of it, both hardware and software wise, without spending much more money.

Basic specs:
Sempron 2200+ (1.5Ghz)
768mb of PC2100 ram
160GB Seagate HDD
PVR-150MCE
ATI 9200SE Videocard

Display:
32" SDTV via S-Video Out

What I'm looking for is general guidance on how I could best improve my setup. I am running SageTV which I just invested in the newest version, so I would like to make everything run its best to get my moneys worth. I also just purchased the new PureVideo decoder to use on the system.

As of now, I have SageTV set on the defaults for A/V settings. Using the SageTV Audio and Video MPEG2 decoders. Nothing else is configured, I have AC3 filter and XVid installed, but to my knowledge there not being used. My questions are as follows:

1. How would you rate my current videocard as far as tv-out quality is concerned, with respect to the display I'm using. This is the only piece of hardware I'm willing to upgrade, if I can get improved IQ without spending a ton of money.
2. Is using DScaler necessary? To my understanding it de-interlaces video, and since my SDTV is an interlaced display, would I be correct in saying DScaler would be useless?
3. Is there any sense in using FFDShow at all considering the processor I'm running, as well as the fact I'm only outputting to a 32" SDTV?
4. Will the PureVideo decoder I purchased work fine with my current setup? I can't seem to locate any config interfaces for it, I just installed it and it's sitting invisible on my system.
5. As far as audio is concerned, is AC3 filter what I want to have enabled in SageTV, and that's it? I'm just doing stereo output to the television's speakers.
6. What would you suggest I use software-wise in general, given my hardware and display? Decoders/software/etc. in order to get the most out of my hardware.

Thanks for helping to point me in the right direction!

 

[IDversusEGO]

1. I would go for a minimum of a directX9 card. If you are buying new, mght as well go for a 6xxx series card, as they are cheap now. 6600 is a nice card for an AGP system.

2. I don't use dscaler and I like my results.

3. Resizing is useless. you could see some results from some of the other numerous filters FFDshow provides.

4. well, you have it installed, but you have to select it in the sage setup menus to use it.

5. for stereo, you should be ok with the purevideo bronze (the $20 one). AC3 is what I use for everything though. If you go in the AC3 setup, you can set alternate codecs for AC3 to use if AC3 can't do what you are asking.

6. honestly, I have played with a few different saftware setups and haven't seen much difference on my SDTV. biggest difference I saw was going from ATI to nvidia. the Nvidia svideo output seamed a little clearer, but the ATI was much brighter.