Good luck! I had nothing but trouble trying to split the HDMI out of my 8600GT video card thru an older Gefen 1:2 HDMI splitter to feed a 1080p plasma and my home theater processor that outputs to a 1080p projector for the longest time.
That said, I now have something more workable. Originally, I had a 1:3 splitter trying to feed the above and a HDFury2 and some other HDMI->Component converter to feed my whole house video distribution hardware. Neither worked well so I abandoned that idea. I use Windows Media Center so instead I hooked up an extender and feed the component video output of the extender into the video distribution. Granted, extenders can't stream DVDs but we've been ok with the limitation "go to the theater to watch a DVD" as most of the content viewed outside the theater is just TV or video games anyway.
Anyway, back to the PC and splitting HDMI. My Vista Media Center had the 8600GT hooked up to an older Gefen HDMI splitter. The direct feed to the plasma was fine except when you first power on the TV. It would always come up with snow, indicative with HDCP handshaking issues. Pressing the PC power button on the remote puts the display to sleep and pressing it again wakes it up and forces it to renegotiate the handshake. All would be well again until the next power cycle of the plasma. If I turned on the HT processor (which is hooked up to the 2nd HDMI out on the splitter) it would cause the handshake to go all haywire but cycling the PC power button to blank the display and bring it back up would also fix it. According to the Gefen instructions, the splitter would take the EDID profile of the display hooked into port 1 (my Panasonic plasma) and present that to the source equipment (the PC in this case). I found no matter what I did, the Gefen always took my HT processor's EDID profile (Anthem Statement D2) even when it was off and presented that to the PC. Didn't matter what order things were turned on or what port the displays were plugged into. I even got the current model HDMI 1.3 capable Gefen 1:2 splitter early this year to try and it was the same issue. Anyway, I dealt with it for over a year.
When the Windows 7 betas started becoming more mature, I set up a test machine to tinker with. It has a better video card - a 9600GT among some other hardware probably irrelevant to the issue at hand. I was so pleased with the betas, I swapped out the Vista media center with the Windows 7 box. I also put the newer Gefen HDMI 1.3 splitter in again to see what would happen. Viola! Almost all my HDMI issues went away if I use the generic EDID profile in the Gefen splitter. It always keeps the same profile to the PC so now no more HDCP handshaking issues when the TV is turned on. The Gefen does renegotiates whenever the plasma or HT processor is turned on. The Gefen has a blue light in the front to indicate when it has a successful handshake so turning on the equipment causes a pause and you hear Windows 7's new hardware detected blip followed by the blue light coming on the Gefen. If I turn on the HT processor while the plasma is on, everything blanks out, Windows 7 gives the hardware removed blip then the hardware discovered blip then the blue light on the Gefen comes on. Sometimes my HT processor doesn't get the handshake right but switching to another input and then back usually fixes it.
You best bet is to make sure you get the latest HDMI hardware and make sure you use the latest drivers for the video card in your machine. Hopefully you'll get a configuration that is manageable but don't expect it to be plug and play!
That said, I now have something more workable. Originally, I had a 1:3 splitter trying to feed the above and a HDFury2 and some other HDMI->Component converter to feed my whole house video distribution hardware. Neither worked well so I abandoned that idea. I use Windows Media Center so instead I hooked up an extender and feed the component video output of the extender into the video distribution. Granted, extenders can't stream DVDs but we've been ok with the limitation "go to the theater to watch a DVD" as most of the content viewed outside the theater is just TV or video games anyway.
Anyway, back to the PC and splitting HDMI. My Vista Media Center had the 8600GT hooked up to an older Gefen HDMI splitter. The direct feed to the plasma was fine except when you first power on the TV. It would always come up with snow, indicative with HDCP handshaking issues. Pressing the PC power button on the remote puts the display to sleep and pressing it again wakes it up and forces it to renegotiate the handshake. All would be well again until the next power cycle of the plasma. If I turned on the HT processor (which is hooked up to the 2nd HDMI out on the splitter) it would cause the handshake to go all haywire but cycling the PC power button to blank the display and bring it back up would also fix it. According to the Gefen instructions, the splitter would take the EDID profile of the display hooked into port 1 (my Panasonic plasma) and present that to the source equipment (the PC in this case). I found no matter what I did, the Gefen always took my HT processor's EDID profile (Anthem Statement D2) even when it was off and presented that to the PC. Didn't matter what order things were turned on or what port the displays were plugged into. I even got the current model HDMI 1.3 capable Gefen 1:2 splitter early this year to try and it was the same issue. Anyway, I dealt with it for over a year.
When the Windows 7 betas started becoming more mature, I set up a test machine to tinker with. It has a better video card - a 9600GT among some other hardware probably irrelevant to the issue at hand. I was so pleased with the betas, I swapped out the Vista media center with the Windows 7 box. I also put the newer Gefen HDMI 1.3 splitter in again to see what would happen. Viola! Almost all my HDMI issues went away if I use the generic EDID profile in the Gefen splitter. It always keeps the same profile to the PC so now no more HDCP handshaking issues when the TV is turned on. The Gefen does renegotiates whenever the plasma or HT processor is turned on. The Gefen has a blue light in the front to indicate when it has a successful handshake so turning on the equipment causes a pause and you hear Windows 7's new hardware detected blip followed by the blue light coming on the Gefen. If I turn on the HT processor while the plasma is on, everything blanks out, Windows 7 gives the hardware removed blip then the hardware discovered blip then the blue light on the Gefen comes on. Sometimes my HT processor doesn't get the handshake right but switching to another input and then back usually fixes it.
You best bet is to make sure you get the latest HDMI hardware and make sure you use the latest drivers for the video card in your machine. Hopefully you'll get a configuration that is manageable but don't expect it to be plug and play!
