I've got a fairly well-equipped HP z555... Pentium 4, 1GB, GeForce 7300GS, etc. Analog channels play just fine, but digital ones are inconsistent: Sometimes they're perfect, sometimes they stutter quite a bit.

Here's the kicker: I get almost the exact same results whether I use an ATSC tuner/antenna *or* an HDHomeRun tuner using QAM channels.

My video drivers are codecs are all up to date. I initially thought this was an antenna issue, which is why I decided to try QAM. But now I'm wondering what else could be to blame. Any thoughts?

Thanks!

When you say digital ones, do you mean HDHomeRun or ATI DCT?

What exactly do you mean by "inconsistent," are there drop outs or what?
Either way, if you record and playback, do the "inconsistencies" always occur in the same place?

Have you tried to download HD video from anywhere else, and test to see if it plays back fine?

How many tuners do you have going at the same time? Have you tried to correlate the issue to a single tuner, or does it affect every tuner equally? If you have four tuners, try to record four HD shows at the same time. Then play back all four looking for the problem. Go into the recorded TV history to see which tuner recorded which program. Try to find a pattern.

I know this can be very frustrating, I was having the same problem and in the end it was an out dated NIC driver and a duplex mismatch with my switch (NIC auto-negotiated to 100/half). I had to replace my switch and now the issue is resolved. The problem is there are so many variables, it's hard to say without more troubleshooting.

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Ben
How good can it be, if it isn't HD?
Engadget HD

bjdraw:

When you say digital ones, do you mean HDHomeRun or ATI DCT?

What exactly do you mean by "inconsistent," are there drop outs or what?
Either way, if you record and playback, do the "inconsistencies" always occur in the same place?

Have you tried to download HD video from anywhere else, and test to see if it plays back fine?

How many tuners do you have going at the same time? Have you tried to correlate the issue to a single tuner, or does it affect every tuner equally? If you have four tuners, try to record four HD shows at the same time. Then play back all four looking for the problem. Go into the recorded TV history to see which tuner recorded which program. Try to find a pattern.

I know this can be very frustrating, I was having the same problem and in the end it was an out dated NIC driver and a duplex mismatch with my switch (NIC auto-negotiated to 100/half). I had to replace my switch and now the issue is resolved. The problem is there are so many variables, it's hard to say without more troubleshooting.

Thanks for such a detailed response. Let me simplify this and say that I've taken the HDHomeRun out of the equation; now I'm back to using the ATI OTA tuner with an antenna (along with an analog dual-tuner card, which has been 100% fine).

MCE 2005 shows full signal strength for all my selected digital channels (about seven in all), but when I watch some of them live, I get stuttering playback. Sometimes this goes away if I switch to another channel and then back again. But recordings were usually okay, at least until recently: Now I'm getting video dropouts and/or "tuner not found" messages, usually about 30-40 minutes into any given recording.

Thought maybe it was an antenna issue, which is why I tried the HDHomeRun and QAM. But it produced very similar results, making me think something else is to blame. But what?

Thanks again for the help...

I am using a HDHR. I was having a similar "stuttering" problem on some digital OTA channels, but not others, using an Asus S-presso with a P4-2.4/1GB RAM MCE2005 box. I have a Radeon x1050 (runs cool). I updated to the latest Catalyst MCE drivers and all is well! No other changes done...

thewarm:

I am using a HDHR. I was having a similar "stuttering" problem on some digital OTA channels, but not others, using an Asus S-presso with a P4-2.4/1GB RAM MCE2005 box. I have a Radeon x1050 (runs cool). I updated to the latest Catalyst MCE drivers and all is well! No other changes done...

I do have the latest Nvidia drivers, so I've ruled that out. Alas, I've had to ditch the HDHR and go back to antenna, which seems to be working well now. Go figure.

I am experiencing similar "stuttering" problems, although it's not all the time.  Certian shows/times.  Not sure if it's a content provider issue or with my HTPC.  I always thought it was a RAM issue.  Or, processor...   But, that doesn't make sense to me.  I've to 2gb of ram, and duo-core.  I think it's plenty of horsepower. 

I just figured it wasn't able to process the information as quickly as it was coming in and would occasionally "stutter". 

As far as the service issue, it rarely does it on my other tv, just using the Comcast set top box, so I don't think it's a service provider issue. 

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HTPC Novice

Problem solved! Turns out my video card was set to 1920x1080, a higher resolution than it could handle. I dialed it back to 1360x768 (which is where it was originally, when all was well), and everything's good again! Sheesh, sometimes we forget to check the simplest things...