DVR hard drive question

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xyz38

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For tech savvy posters.

Does the 16 tuner Hopper3 have a hard drive with only one read/write arm like the computer hard drives?
If so it must be very busy while recording several programs and playing a couple of recordings in two rooms at the same time.
It will even play one recording in two rooms with it starting at different times while recording several programs at the same time.
How does it do so many things without messing up?
 
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Jim5506

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Yes it has a standard spinning disk computer like hard drive optimized for constant use and re-writes.

That it can keep up with that many tuners is an indication of how competent computer hard drives really are
 
KAB

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The HWS's had a bad batch Seagate HDDs when they first came out, and many, including me had to get a replacement box. I can not recall any problems with the H3's of late. They are rock solid, IMO.
 
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DishSubLA

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a long a long time ago, something like maybe 10 years ago, dish did have a prototype DVR that would record several tuners. I don't remember exactly how many tuners, but it was something like less than 10, but the hdds were found to prematurely fail, so that DVR was nixed. I can't remember what the source was, but it may have been mentioned on an old Tech forum; I can't recall. So yes, what makes the H3 possible are the advances in the reliability of the HDD's today.

TiVo DVR's currently top out at 6 tuners per DVR, but that's only because CableCARD can accommodate only up to six tuners. TiVo DVRs Also Serve their version of joeys called Minis, so you're talking about 6 simultaneous recordings and then simultaneous playbacks from throughout the home using a TiVo DVR and a number of Mini's. Further, several TiVo users have upgraded their TiVo DVRs Beyond 3 terabytes up to 6 terabyte internal HDD and Report no problems. There was a time when dealing with this type of density and work would have killed HDD's pretty quickly, but again this is evidence of how well we make HDD's today with such high density in great reliability that can last year's even being punished while doing so.

As for me, I would never have anything greater than a 3 terabyte HDD for anything because the density is required beyond that to me could produce too many errors and you looking at some problems further down the road and it creates even more HEAT compared with lower capacity HDD's, but that's just me.
 
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ncted

ncted

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Well, most AV hard drives have greatly reduced error correction, which is the biggest thing that slows down high capacity, spinning disks. In addition, I suspect there is something Dish is doing in how it writes the data to disk. I suspect there aren't actually 16+ streams being written simultaneously. There is a some multiplexing going on somewhere. My question is how does the software manage to read it back out correctly? That is where the magic is IMHO. Of course, Dish's low bit rates probably contribute to this technology's success.
 
TheKrell

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a long a long time ago, something like maybe 10 years ago, dish did have a prototype DVR that would record several tuners. I don't remember exactly how many tuners, but it was something like less than 10, but the hdds were found to prematurely fail, so that DVR was nixed.

And yet they OK'd the DSR100.
 
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kwindrem

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For tech savvy posters.

Does the 16 tuner Hopper3 have a hard drive with only one read/write arm like the computer hard drives?
If so it must be very busy while recording several programs and playing a couple of recordings in two rooms at the same time.
It will even play one recording in two rooms with it starting at different times while recording several programs at the same time.
How does it do so many things without messing up?
So you could record 16 things and play back another 7 or so (with 5 Joeys plus main and PIP on the Hopper). This really isn't a big strain on modern hard drives. Streams will be buffered into efficient packets (I'm guessing between 1 and 10 seconds worth of data at a time) then written to the drive. Based on typical storage requirements, I estimate a typical dish video stream is about 4 megaBITS per second so each stream uses about 0.5 megaBYTES per second. Total requirements for 24 streams is 12 MB/sec and most hard drives can easily do 3 times that much. Disk accesses for say 5 seconds worth of material would take under 100 mS. There would only be 24 disk accesses every 5 seconds in this scenario leaving plenty of time for head movement. Hard drives used in computer systems are subjected to similar random reads and writes at times. But applications like audio and video editing would place higher sustained disk activity than a satellite receiver serving 24 streams.

You can get an idea of how busy a hard drive is by listening to it. You'll be able to hear the head movement. I suspect what you'll hear with a busy Hopper is head movement every 1/10 to 1/4 second.
 
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xyz38

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If I decide to add an external hard drive to the Hopper3, what is the best brand and is there an activation fee?
I have two Western Digital external drives, one 2tb and one 4tb, on my desktop computer and have never had a problem with them.
 
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DishSubLA

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And yet they OK'd the DSR100.
I should add that originally, the 50X's had their HDD's constantly spinning, but then Dish sent a firmware update to have the HDD's spin down when not recording or being viewed for playback/live because in the words of Dave Kummer (or was it spelled with a "C"?) "It'll add a little more life to the hard drive there," and that's when Mark Jackson gave Dave one of his (Jackson's) trademark GLARES of volcanic eyes, as if to say, "don't say that!" That I do remember from a long ago Tech Forum. It made be laugh because I always laughed when Mark Jackson gave his "bollocking" glare towards someone on staff. I think having the HDD's spin down on those units also addressed the many complaints of noise for those who had the 50X's in their bedrooms, me thinks, only to be replaced by the many noise complaints of the fans from subsequent early model DVR's in bedrooms.
 
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DishSubLA

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Let's also remember that there have been plenty of 16 or so channel DVR's for video surveillance using a PC out there for a number of years before the H3 that have had similar demands. I remember our company's first DVR was a 12 channel DVR we had installed some 6 years ago I'm gonna guess, but such DVR's pre-date even our first install. Of course, an H3 does more than just record and it is not a full fledged PC, so the challenges for a Dish H3 is probably even more difficult to produce at a decent cost.
 

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