What affects flash and streaming?

A very basic question, but something that I haven't really thought about before. What are the performance hits that affect flash video and streaming in general?

I'm asking for two reasons. First, my wife loves XM but for some reason, on her machine she has frequent problems with the stream stuttering and sometimes locking up entirely. On my computer, I can't make flash video full screen or the framerate drops at least 50%. I really like Hulu, but I can't watch it in a little window.

Normally I would assume the usual suspects, but we have FIOS with a steady 5mbps down, so I would assume streaming music would be no problem, and my machine, while a bit old, is still a 3.2GHz system with a gig of memory. Besides, neither machine is working too hard when performing either of these tasks. If I've already buffered the video I don't see why a large resolution should kill the framerate. Is that just a limitation of flash video?

Check video drivers? Version of flash? Reinstall Windows if all else fails...

If you've got a problem playing movies full screen, but the same exact movie file plays OK at smaller windowed sizes, definitely suspect bad video card drivers or a slow video card.

Also, just because you get 5mbps downstream from your internet service provider, that doesn't mean the server that's feeding you the video stream is *sending* it at 5mbps. Perhaps that server is overloaded and/or is throttling its output?

Also, I've heard talk of some ISP's who deliberately throttle certain types of content. Although I've only heard about that in terms of peer-to-peer file sharing, it's conceivably possible that your ISP could be throttling multimedia streams as well.

Also, are there any settings in the player software that control how full screen video is played? Perhaps it's not using an optimal method for stretching the video image to full screen.

Watching my task manager on a dual 3.2ghz Xeon (P4 era, so 4 years old now), watching an HD video on Hulu brings Firefox usage to 35-45% so nearly one processor used. Going full screen ends up jumping to 60%, so it's using more then one processor.

If I get some time later, I'll try to grab the ATI development tools to see how much, if any, is being accelerated by the video card. With the CPU jump, it looks like not much in either decoding, or making it full screen.

Thanks, folks. I guess the video has more impact than I thought it would. Makes sense, I suppose.

The audio streaming is still strange to me. When I log into our XM account, it streams fine on my computer for as long as I want it to. On her machine it goes bad after about 10 minutes. Maybe her computer is just getting old...

Is there anything at all different in the network connectivity between the good machine and the bad machine?

"going bad after about 10 minutes" indicates to me that you've got packet retries piling up somewhere.

Nope, no difference. They're both connected to the same router.

I just want to add that I've never had a good experience streaming from XM's feed. I don't know if it's flash-based now, but last I tried it was some sort of 64k WMA stream. The thing would work fine for a couple minutes, then it would have to rebuffer constantly.

Now, if I want to listen to XM at work, I log in to my slingbox and stream from my DirecTV receiver in audio-only mode. The audio quality is noticeably better and it never runs out of buffer.