well I used a cat 5 from my router to my computer and it was better but still not perfect. Next I got another cat 5 and hooked up my ps3 to the router and it is now working perfectly!
I did not realize you were dealing with two independent wireless links. Since the computer and the PS3 talk through the wireless router, not directly to each other, they are contending for the same over-the-air bandwidth. Each packet of each image must go over the air twice. This makes the situation much worse than when one of the two is hardwired.
The point that I would make is that running HD wirelessly is hard. Since high frequency radio waves propagate in novel and unexpected ways, if you don't have professional setup equipment, your success (or failure) is as much luck as skill.
And because interference is a major contributor to failures, once you get it working satisfactorily today, you never know if it will work tomorrow when your neighbor starts using his new wireless phone set, or baby monitor or wireless camera or any of the hundreds of other devices that share these relatively unregulated chunks of spectrum.
Today's wireless protocols do an amazing job of recovering from errors and trying to reduce the impact of future ones. However, the nature of the errors are that some packets are missed, delayed and then retried before finally reaching the destination.
This is not conducive to good playback of media multiplexed for playback from direct access media. A spinning disc has different failure modes than a lossy network connection.
Good streaming protocols and media multiplexed for them are much more tolerant of the kinds of errors that wireless networks tend to inject into the stream. Wired networks and hardware have similar issues, but at a couple of orders of magnitude lower rates.
You will also find that higher bandwidth connections (wired or wireless) make more of a difference than you would expect. Even with 25-40Mb stream rates, gigabit Ethernet performs better than 100Mb Ethernet, even though the efficiency of 100Mb Ethernet on a switched network is more than adequate for the full HD rate.
I believe that the reason stems from the track cache that virtually all drives (certainly the ones used in computers) feature. While playback is nominally 25-40Mb continuous, the software that reads it does not read it continuously. Instead, it implicitly expects to find it in the drive's cache from which it can be read at a rate several times greater than that at which it came from the media. So, the software reads in bursts at rates that most network hardware cannot match.
At best, this makes network playback fragile and even low levels of errors will disrupt playback. Faster networks tend to deal with these errors better because the excess capacity allows more time to detect the errors and retry than there is on slower hardware that is more congested.
For wireless networks, only Wireless N (802.11n) operating under favorable conditions can hope to do as well or better than 100Mb Ethernet.
Of the earlier wireless standards, A (802.11a) operates with better performance in a marginally less used bit of spectrum and so performs better (which is why it is used on the XBox 360).
Wireless can work for HD, even slow wireless. Even the best wireless will not work under some circumstances. If you find yourself hanging aluminum foil from the antennas, you know it is not going to work for you.
