[Rumz]

I've done some searching and haven't found any relevant threads yet, so I'll just ask the question.

I just bought a Sony Bravia XBR KDL-46XBR4 46" 1080p LCD HDTV. For the short term, while I wait out the HD format war a bit, I figured I'd hook either my Intel Core Duo Mac Mini (1.66ghz, 2gb ram) or my MacBook Pro (Core Duo 2.16ghz, 2gb ram) to the HDTV with a DVI-D > HDMI cable.

Here's what I'm experiencing using either system hooked up to the TV. When playing back either a video file or an actual dvd via front row or just the dvd player, It seems to stutter every 10-15 seconds. It plays smoth for that long and then it seems to be skipping frames so as to look choppy just briefly before it plays normally for another 10-15 seconds.

The MacBook Pro is running Tiger, the Mac Mini is running leopard, and even the MacBook Pro in Windows XP does the same thing (even 3d games appear to exibit the stutter a bit).

So I basically am looking for anyone who's had a similar experience or even just has an opinion on what the symptom means. Either the cable I bought isn't diong the job well enough (I bought one by "Cables Unlimited" off Amazon.com-- everything I've read says that basically these hdmi - dvi cables are not work the premium price brands like Monster charges), or else my TV just doesn't want to play nice with the signal it's being fed from my macs.

Other non-computer sources don't have this problem (stand alone dvd-players)-- playback is fine.

So what do you think it is? Incompatibility between this specific TV and the Macs? Or sub-par hdmi cable? Most everyone who's hooked up their Mac to an HDTV, once they get the resolution set correctly, seem to not have any trouble with the output from their Mac, which makes me think it is another variable besides the Mac (ie cable or tv itself).

Any input would be appreciated if you have any idea what that symptom might represent.

[Big Mac]

Does it do it when you're not connected to the TV?

[Rumz]

Nope-- playback on the macbook pro's screen is fine (no stuttering) and same goes for the Mini hooked up to a 20" Dell LCD.

[Big Mac]

May just not be a good TV for use with computers, unfortunately.

[nonhuman]

That's interesting. I've run 42" Plasmas off a Mac Mini (PPC) no problem. I can't really imagine why the cable would cause the problem, but since it happens with two different computers, either of which should be entirely capable of this, it seems like the problem must be with either the cable or the tv. I'd try two things:

1. Try a different cable (return the one you have for a new one, borrow a different one from someone, buy a new one).
2. Try taking your MBP into Circuit City or some other store and see if they'll let you try hooking it up to the same model of TV with your current cable (or new cable if you do that and the problem persists).

[Rumz]

I think I've solved the problem.

After doing some more digging, I think the culprit is the 120hz feature that seems to be enable by default on the HDMI ports. (Found a post on another forum by someone who indicated running the display at 120hz was causing some stuttering).

By turning it off, the only stuttering I now get on the Mac Mini seems to be a deficiency in dvd reading / playback (happens when you jump to another chapter, takes a few seconds to smooth out). For any Sony users, I had to go into the video options and turn off "CineMotion"-- my guess is that CineMotion represents that 120hz setting. Either way, turning that off seems to have fixed the issue running my Macs to the TV.

Also, for those interested, although the Mac Mini says it's running at 1080 (interlaced), the TV is reporting that it's getting a 1080p signal.