# 508 60 hours?



## narnia777 (Mar 28, 2003)

I have a 508 PVR and something has bugged for a while.

It supposed to have an 80 gig hard drive with "60 hours" recording time right? Well I have filled it up many times to the max and can never get more than 42-46 hours of programming on it.

Why don't I get the full 60 hours? 

Jim


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## tampa8 (Mar 30, 2002)

There are actually a few reasons. Recording a digital signal to a hard drive is different than recording an analog signal to a tape recorder. On a tape, a half hour program takes up the same amount of space on the tape everytime. (assuming using the same recording speed) But the digital signal varies. The amount of information being sent varies by the content, and compression rate. A sports program probably will take up more space than many other shows because there is more motion or information to be sent per second to the hard drive. So, say a basketball game may use up more of the 80 gigs in an hour than a fishing program or a sitcom. In addition it is possible that the compression rate of one channel is better than another. Good for picture quality, but takes up more space on the hard drive.
One other reason, some have posted that a portion of the hard drive is reserved for Dish to download information. Every once in awhile a short clip or advertisement has been downloaded at night to the hard drive and is sent to that area of the hard drive. This would (hopefully) avoid deleting an unprotected program you have recorded if the disk is full.

Think of saving a JPG picture on your computer hard drive. You can vary the compression which impacts picture quality and how much space it takes to save it, and the size of the picture - or information to be saved - also impacts how much space is needed.


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## Ron Barry (Dec 10, 2002)

I was under the impression that the the Dish signal was a fixed 3mb/sec downstream. If this is the case, then why would it the bit rate to the drive change. Has then changed? I thought the reason you saw more artifacts on Sports programs was because of the fixed bit rate. Are DBS not supporting VBR? Have not kept up with it in a while but what tampa states does not go along with my understand. Then again, mine could be dated or totally wrong.


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## Jacob S (Apr 14, 2002)

Some channels are compressed more than others. Those that are compressed more would have less space to take up. Channels with movies and sports tends to have less compression.


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## TomCat (Aug 31, 2002)

VBR is hard to support to any significant extent in STB's, due to the fact that it takes expensive decoders to decode it properly, which STB's don't have. DBS uses VBR, but probably at about a 2% ceiling.

My personal opinion is that DISH fudged the numbers to make their product look good. My "35-hour" 501 fills up at about 27-28 hours. My 30-hour ShowStopper which of course is dependent on the bit rates used internally and not on those in the DBS bitstream (and which also uses 2% VBR) fills up at...30 hours. Exactly. Go Figure.

While statmux and individual rates for different channels are facts, you would probably have to record one of the music channels only to get 35 hours of recording on a 501. So, their "guestimate" of 35 hours is ridiculously unrealistic...a number they basically pulled out of ther asses that has no correlation to real-world usage. It's also annoying to record an hour program and see your counter diminish by 1:12. Especially when that's not really necessary.

They claim in their technical mumbo-jumbo that the varying bit-rate is at fault, but while there is a grain of truth to it, that's about 95% spin. They COULD have picked a reasonably accurate method of calculating the space regardless of those facts, but the important fact to them was that if they did that their PVR's would seem to have less actual space...which they do.


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## Ron Barry (Dec 10, 2002)

So they do use VBR. Hmm I find that interesting because I thought the signal down was a fixed 3Mb. am I wrong here? Are they using VBR with a celing of 3mb?


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## dtcarson (Jan 10, 2003)

The PVR's also constantly buffer, so I would imagine there's an hour or so worth of disk space that is never available for your use. That wouldn't account for three hours, but it does take a little bit. Plus I would assume the PVR software, the EPG, etc, all take up a little more.
It's like a CDR--you could put 'ten hours of music' on one, if your mp3's are 96kb. But if you up the quality of the sound [or picture, or have picture that inherently takes more space to hold the info], you're using more space for less info, but at a higher quality.


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## Jacob S (Apr 14, 2002)

The 721 has two hours of buffer reserved on the hard drive.


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## DarrellP (Apr 24, 2002)

2 years ago when the 501 was new and the Dish signal was compressed to crap, 35 hours was possible, but today with the bitrate up 27 hrs is more likely.


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## Bill R (Dec 20, 2002)

narnia777 said:


> I have a 508 PVR and something has bugged for a while.
> 
> It supposed to have an 80 gig hard drive with "60 hours" recording time right? Well I have filled it up many times to the max and can never get more than 42-46 hours of programming on it.
> 
> ...


Because marketing people lie a lot. They GROSSLY over state the recording time that the AVERAGE user will get. I guess if you record the cartoon channel or some other very highly compressd channel you may approach what the marketing hype says.

I have a 721 (with a 120 GB drive) and the few times that I let the drive fill up (just to see how much I could record) I got just over 70 hours. This is FAR short of the "90-100 hours" that I was told I could expect on the 721.


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## dtcarson (Jan 10, 2003)

Well, a lot of what I have on my 508 is cartoons, and what shows as :30 or :31 on the clock, usually frees up 35-45 on the 'Time Left' when I delete it. And these aren't even very busy, fancy cartoons like some of those CGI things.


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## TomCat (Aug 31, 2002)

DarrellP said:


> 2 years ago when the 501 was new and the Dish signal was compressed to crap, 35 hours was possible, but today with the bitrate up 27 hrs is more likely.


The 501 came out on April 9th, 2001. I foolishly bought one that very day (I'm about to replace it...2 and a half years and its getting a bit long in the tooth). The must-carry crunch deadline wasn't until January 1, 2002, and at that point a lot of channels were being compressed more than any of us liked. When spot beams replaced the two main sats, that eased somewhat, almost to the point things were two years ago.

Point being, at any time in the 501's history, regardless of the compression, my unit filled up at about 27 hours, before, during, and after high compression from DISH. I don't think capacity ever was any better and highly compressing the channels like they did in the first part of last year seemed to make little if any difference. In short, I consider the compression changes at DISH to not be a factor, and only one more spin opportunity to confuse the issue and hide the fact that they picked an unreasonably ridiculous number out of the air in the first place purely for marketing purposes, just one more indicator of the level of arrogance we're dealing with.

The capacity also never increased when the 501 "magically" morphed overnight from a "30-hour" unit into a "35-hour" unit (this about 2 OS up revs in...P116 or P118 I think). I'm not sure how or why they did this, but it really didn't seem to increase capacity. I think they actually (and foolishly) reformatted the HD in place or some kind of black magic related to that. I would also guess that they were ultimately sorry they did, as many users lost from 30 to 100% of existing recordings in a single shot and folks still had recordings disappearing from their HD's for months afterward.


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