DVI to HDMI issue

[unsecluded]

Hey guys, need some help here

I have a 23" connected to my PC via DVI on 8800gt.

Bought a Sinotech 40" 1080P LCD for the room. Connected PC to it via DVI-VGA adapter and VGA cable, and it worked fine. Obviously i wasn't getting the 1080P, should probably get 1080i but couldn't even get that either. Just left it to handshake issues over analog. Anyway, i'm not too concerned with that because watching 1080p movies is why i got the tv. That aside, it managed a max of 1680x1050, everything playing smooth, no graphic problems at all, running extended desktop.

So yesterday i got a DVI-HDMI cable. The PC picked up the tv as an HDTV connected via HDMI no problems. Displayed 1080P on both monitor and tv no problems. But when i play anything, 720p video, AVI, etc., the playback stutters or jerks slightly whether on the monitor or tv. Tried every combo of resolution:Hz setting, right down to 800x600, and still stutters. Disabled tv from dual mode and still stutters on monitor. Disabled monitor, stutter remains on tv. Changed cable back to VGA and all works well again. Now i'de normally be satisfied with the VGA connection, but the reason i paid for 1080p was for 1080p movies. Any ideas on whats the issue?

 

[Chevron]

Gonna say obvious but update your graphics card drivers.

Secondly how's your cpu usage when playing HD stuff?

 

[unsecluded]

Nvidia and gfx bios updated to latest drivers.

Machine spec: q6600, 4gb DDR2 ram, Asus 8800gt TOP
OS: Windows 7

CPU usage is fine, even to the point of running smoothly a 720P movie on the 40" whilst playing a game on the 23", but that's through the VGA cable though.

 

[jetlee]

just be carefull .. play a full quality source on 1 monitor .. then check the CPU usage .. I have about a dual core 4600 AMD in my media centre (not exactly sure of thee spec .. but around there) and I have to switch deblocking off when watching full 1080p content if I want it super smooth .. sometimes in high motion scenes it stutters .. also . try the Core codec for MKV's its a little less intensive than most others Ive used

 

[unsecluded]

just be carefull .. play a full quality source on 1 monitor .. then check the CPU usage .. I have about a dual core 4600 AMD in my media centre (not exactly sure of thee spec .. but around there) and I have to switch deblocking off when watching full 1080p content if I want it super smooth .. sometimes in high motion scenes it stutters .. also . try the Core codec for MKV's its a little less intensive than most others Ive used

I am using MKV

What's 'deblocking' and where do i turn it off ?