Compression ratio for 501 508 510

[miguelaqui]

A 501 has a 40 gig hardrive, 35 hours of recording; approx 1.14 hours per gig

508 has an 80gig hardrive, 60 hours of recording;approx 1.33 hours per gig

510 has a 120gig hardrive, 100 hours of recording; approx 1.2 hours per

Does this mean that a 508 will have a better picture than a 501 or even a 510?

Expressvu's versions

5100 30 hours of recording; 1.33 hrs. per gig
5800 55 hours of recording; 1.09 hrs per gig
5900 80 hours of recording; 1.5 per gig

Does this mean that EV's 5900 will have a better picture quality?

 

[jayn_j]

Nope. If you figure on 1 GB/Hour, it will show that dish reserves about 20 GB on the 510 and 508, and 5 GB on the 501 for guide data, internal use and a "special" area for dish messages.

We've known about the dish reserved area for some time.

 

[TuxCoder]

Also, regardless of reserved areas, it's actually less hours per gigabyte (lower compression) that "should" result in better picture quality. Thus, if just going by the above numbers you list, the best picture would be more likely on the 501 and the 5800. The 508 and 5900 would be more likely have the "worst" picture.

 

[kavula]

miguelaqui has his math messed up.
He has his units turned around in his initial post. He meant that:
501 - 1.14 GB/hr
508 - 1.33 GB/hr
510 - 1.2 GB/hr
--- GB/hr instead of hrs/GB ---
In this case, the greater, the better.

BUT, E* varies the compression used on each channel. The DVR's simply write the entire data stream to disk, so the GB/hr figure does not depend on the receiver, but entirely on E* (e.g. HBO is compressed less than basic channels, so it takes more room to record the same time). These recording time figures for each receiver are only nice, round estimates. Nothing you should read into about the capabilities of each receiver. On my 501, I can't quite record all 35 hours.

 

[GaryPen]

All three models are identical, except for hdd size. They process the signal in exactly the same way. Those numbers are just marketing hype. Easy to round off.

 

[SimpleSimon]

The space needed also depends on the type of program being recorded, not just the "average" compression E* has set for the channel. Channels on a given transponder are compressed using statistical multiplexing. A high-movement program requires more bandwidth, and therefore more disk space.