Let's set this straight - No one can do 24p consistently well

Well I have an ATI card, but I didn't buy it because of the 24p playback bug. I bought it because the integrated graphics of the intel i3 was not cooperating with my system at the time. I have considered trying it again since all the updates have come out. (SP1, driver updates, etc.)

However, I would really like to know the REAL WORLD effects of these frame rates. In other words, it seems like being off by 2 or 3 or 4 one thousanths of a second would not really affet the picture much. For myself, although I do not look for skipped frames or slight pauses, I never see them when playing back video at either 59.9~ (59hz) or 23.9~ (23hz).

So I am just trying to figure out what everyone else sees . . .

Is that "with UAC off" only for Sandy Bridge or does it work with Clarkdale too?

And how does the coordinate with having to have it on to use Shark007 to get HD Audio?

At any rate, I don't even notice a problem with it.

You sure about this? From what I recall, the UAC off fix only works for Sandy Bridge...

Me too. I've had an ATI card for a while now, tried the whole 59/60 vs 24p thing and never noticed a difference. So I just set it to 60hz and never looked back. Ignorance is bliss I guess.

That is not ignorance. This is having enough knowledge to be able to just enjoy what you have.
My eyes are my judge. When I like what I see, I am also content to watch the video/movie in its entirety.

In all my years of PC video playback, I have never once concerned myself with fps data.

And would only be an issue if your TV was actually outputting at 24p *and* you have sensitive enough eyes to notice it. Pretty rare combination. Not to say it doesn't drive some people mad, but the vast majority will never see it, even if they do have a true 24p HDTV.

Having once been a diehard audiophile I have since learned that if you aren't aware that a problem exists, don't go looking for it. I don't know what to look for in detecting the "24p bug" and I have no desire to find out what it is I should be seeing. I'm perfectly content watching Blu-Ray rips on my HTPC the way things are. If I knew what the 24p bug looks like it would ruin whatever enjoyment I get out of the media.

What does turning UAC off do? and how do I do it?

But what does it do for or against me?

UAC prevents somebody (your wife, children etc.)/something (virus) from changing the system accidentally/intentionally. If I were a system integrator, I would never recommend my customers to turn it off (as I can't take responsibility for results). Personally I never turn it off for the same reason.

You seriously leave that thing on on your own pc? I can see for someone you built or whatever, but that annoying thing is the first thing I kill after a reformat.

Is that so annoying? (Vista's UAC is surely annoying.) I tested virus and UAC was pretty effective to protect OS (perhaps those who mention disabling UAC casually have never experienced this). It has been also very good to stop my wife/kids changing the system. Anyway I would always add a comment on possible consequences when mentioning disabling UAC to somebody.

Ok so how does it benefit us to disable it? I haven't disabled it and so far everything seems to work, even movies in mb and live tv and I don't know what everyone is talking about stuff "breaking"?

Have you ever noticed stuttering every 42 seconds when you play movies with the desktop resolution set to 24Hz? If no, disabling UAC won't benefit you at all.

I have an ATI 5670 card and the 23.976 occasional stutter irritates me. I use TMT3 for Bluray playback and the occasional stutter seems to throw out the sync of TMT3 and then it will begin to stutter a lot. Some times I wish I had just stayed with DVD.

Well I've been considering trying another video card, but if all cards are having this problem I will just save my money for now. Thanks for the info.

Gary.

Intel HD Graphics supports only 24.000 Hz refresh rate (if you don't disable UAC [disabling UAC could cause A/V synch issue]), so if you play a movie of 23.976 fps, you will see an extra frame inserted every

1/(24.000-23.976) =

41.666... seconds. That's the cause of a periodic stuttering (but not everyone can notice it). If a Radeon card supports 23.978 Hz refresh rate, then you will see an extra frame inserted every

1/(23.978-23.976) =

500 seconds = 8 minutes 20 seconds. It's still a periodic stuttering, but it's even harder to notice it (and as a matter of fact everybody thinks it's practically perfect).

If someone feels stuttering is irritating, perhaps the cause is entirely different from the imprecise refresh rate.

For some people, turning UAC off is the cause of a mutitude of problems that I cannot explain.

I run my own (playback) forum and occaissionally a user with weird things going on can correct their problem(s) by removing my software, re-enabling UAC, and re-installing my software. For some reason (and for only some people) which is beyond my understanding, choosing to disable UAC does not allow codecs to register properly or the registry to be manipulated as designed by my settings interface.

UAC turned off can effect other software as well. I normally have it off on my non-HTPC's but when having a lot of trouble installing Logitech web cam software on my wife's computer and I turned UAC back on for her and it installed perfectly. So Shark, your software (or the codecs in general) isn't the only thing that seems to need UAC on to install/run properly.

It's weird. I personally just keep UAC on now on all my Win 7 machines. Frankly once I have everything installed I rarely ever see a UAC notice. It's really not that annoying on you're installed and all set.

That is a different problem, and I've noticed it when using ATI 5000 series cards with TMT3 or TMT5. In my experience, it doesn't happen if you stay in Aero. Or, you could use reclock to force vsync and it won't happen. If you can get past this problem, ATIs are close enough to 23.976 that I haven't noticed duplicated or dropped frames when watching BDs.

With Clarkdale or Sandy Bridge integrated graphics, I definitely notice the duplicated frame every so often. I don't notice it every time that it happens, but I'll notice it a few times during a typical movie.

seems like a lot of trouble to go 24p. Why not just stick with 60hz and do 3:2 pulldown inverse telecine. So what pan shots are jerky?

I purchased a Intel Clarksdale when they first came out, thinking 24p would work OK, and could just their Internal graphics. But none of the reviews bother mentioning Intel only output 24hz. So I saw the jerk/stutter within probably 2 minutes of the first thing I played. Then I checked the output output on my DVDO and front PJ, and saw 24hz.

Well, I knew right then it would jerk because I already had wasted lots of time trying to get 23.976 before the Clarksdale, using a Nvidia card at that time. Even though at first there were arguments in the Clarksdale thread about it, I didn't have to look for the stutter, its just there to see.

Sure, it kind of depends what type of motion is going on at the time to really see the jerk clearly, but happened enough (~40 sec) that I wasn't interested in using it. Also, After watching 23.976 I can see the difference between it and 59.94, or in Intel's case 60hz. Plus most blu-ray is encoded 23.976. Maybe screen size matters also.

When SB came out I waited to see if a review would mention 24p and this time of course they did, plus adding that it was a Hardware problem all along. Which is nice since Intel wouldn't admit it with Clarksdale, and time was wasted trying to deal with their useless support. So of course I had no reason to buy a SB for HTPC myself after hearing that. If I had who knows, maybe I wouldn't have noticed a problem since I always turn UAC off when I install windows 7. But I'd have to see it for myself.

The ATI 5450 card I picked up works fine and I don't see any stutter. Apparently its close enough. Clarksdale's 24hz isn't. SB I don't have and never will. Might for another computer but not for playing Blu-ray.

I'm waiting to see how AMD's Llano will work. I really don't care about what numbers are showing regarding 23.976, as long as I don't see that stutter. Plus with a HTPC many other things can cause video jerk. But for me, the Intel Clarksdale was a waste of time.

I used all three cards and never was able to get perfect playback. I must have very sensitive eyes, but I saw EVERY frame skip/drop. I could tell the time to within 5 minutes because of the periodic nature of the frame skip. With intel it was every 40 seconds, with ati it was every 7 minutes, with nvidia every minute.

Eventually I just moved to a sagetv extender and now I have no issues.