Sapphire HD 3850 AGP 512MB 1080p problem...

I've got a Sapphire HD 3850 AGP 512MB card running on a P4 2.4c OC'd to 2.7 with 2GB PC3200 RAM on an Asus P4P800 Deluxe mobo.

I've been googling this question for days and I've read some posts that this problem has been solved. However, no one has given a step by step explanation on how to get it working and I'm new to the whole HD thing so I hope someone here can help me out.

Gaming works great with this card. I'm running games like Oblivion and Fallout 3 with good results, and older games like Half Life 2 are just flawless. I'm satisfied there. I've tried overclocking the card however I haven't seen any improvements in gaming. I know the stock heatsink and fan isn't that great, however my case is really well ventilated, and I've watched the GPU temp never go past 70 C when overclocked, and it stays below 60 C when I got it running stock.

My problem is with HD playback. That's one of the reasons I got the card. I found out later that the HD 3xxx series that are AGP and built by third party developers aren't that great and have had a whole bunch of problems. Nevertheless, I'm come across tons of posts reporting a lot of the issues have been solved.

The problem is that any HD playback can and should be processed by the GPU. However, when running a 1080p MKV the GPU stays at around 1-2% while my CPU load hits 100%. This is the reason I'm getting stuttering video and sound. I get that. I've also read that some guys have managed to get the GPU to do the processing, but I haven't found any real instructions on how to do this. If anyone could help me out on this one, I'd really be grateful.

I agree with you 100%, but all my spare cash at this point is going into my '89 Mazda 323 Turbo. And like I said before, I've read posts that people with a P4 2.8 have been able to run HD without a hitch as long as the GPU is doing the work. So back to my original question, what codec/player combo should I be looking at to get my HD 3850's GPU to take over the processing of 1080p videos as opposed to dumping it on the CPU? I heard there are players (or maybe it was some sort of codecs) out there that would let you force the HD video to process through the GPU using ATI's Avivo codec. I've installed that codec, and I've downloaded a few players that have the feature to make my graphic hardware do the work, but when I run the video the CPU still hits 100% load while the GPU is practically at idle.

I don't know what 'S.O.L.' means.

Assuming you mean a P4 will never play a 1080p mkv, fine. Lets just accept that fact for now. You guys are still not answering my question. How do you get the HD 3850's GPU to take over the decoding of h264 mkv's, lets say its a 720p which I can play no problem, but still ends up putting almost 100% load on my CPU. The HD 3850 GPU is supposed to be able to do the decoding so the CPU doesn't have to. How do I go about setting that up?

*** outa luck

power dvd will use it to decode legit bluray from a bluray disc

read this also (and follow the links) :
http://en.wikipedia.org/wiki/CoreAVC