I 've done a bit of a search on the forums, but not come up with any real idea of what download data transfer rates people are obtaining from the Topfield 5000 (April 2004 firmware) to a PC.

I've had the PVR unit since October, but not had equipment to try out the PC connection. Nevertheless it is a feature I want to use in the future, and I was grateful to a friend who came over on the weekend to try it out (mind you, he has a motive too, as a potential buyer).

He has a much more modern PC than me (1.6 GHz Celeron laptop, 512 MB, USB2, Win XP, DVD burner). He had not downloaded Altair from the Topfield Australia site, but from an auxiliary site which had a more recent version available.

Results were surprising to both of us. The data transfer rate was 4 GB/hr, barely 50% above real time broadcast rates (2-3 GB/hr)! If very basic editing will suffice, you might as well just feed the output of the Topfield into a deck DVD Recorder.

By comparison, the data transfer rate from a USB memory stick on this computer was 38 GB/s (depends what memory stick you're using of course. This presumably shows that the Topfield speed limitation doesn't inherently lie in the PC.

I could hypothesize, but it seems more useful at this stage to enquire what data rates people routinely expect from the Topfield, given a computer of this general calibre, and take it from there.

Thanks in advance,
Peter

Looks like you are on the wrong forum groups....

Take a look at this group,

http://www.topfield-australia.com.au/frm/default.asp

and this thread in particular.......

http://www.topfield-australia.com.au/frm/t...p?TOPIC_ID=1475

Cheers,
Another Peter

I work in bits/s, but that sounds awfully to me like you didn't use the Turbo mode, or you have only got a USB1.1 connection (12megabit/s max, in reality, more like 9 or so megabit/s).... lets see, 4G*8/3600 * 1000=8.9megabit/s.
The turbo speed is about 18megabit/s, which is about 2.5 to 3 times the rate of the program you have recorded.
Regards

38 GB/s? The maximum speed for USB 2 is 480 Mb/s (= roughly 60 MB/s).

We knew it was a USB2 port.

Nevertheless, that was the point of the memory stick comparison, where the transfer speed was 38 GB/hr, or 84 Mb/s, well above the USB1.1 capability of 12Mb/s. Therefore the Topfield or its software was the holdup.

The Topfield was downloading 4 hours (12 GB) of recording in about 3 hours. I'm surprised no-one has a feel for transfer rates - ie if you download a 1 hour program (2-3 GB) to a PC, how long would you expect it to take?

BTW what's Turbo mode in this context (showing my newbie status here)?

Peter

A slip on my part. The Topfield download rate was 4 GB/hr. The memory stick transfer speed was 38 GB/hr (not /s), or 84 Mb/s which is well above USB1.1 capacity and safely within the maximum USB2 rate.

Peter

Thanks, Peter. That thread was most helpful. It looks like people don't expect more than about 3x realtime data transfer rate, so we weren't so far off the mark, although still slower than expected.

If Altair could have had Turbo mode on and didn't (I wasn't the operator so don't know), thus doubling the rate, we would have got a 4 hour recording transferred in 1 1/2 hours, which is in the ballpark.

I'm glad I got a deck DVD-Recorder to tide me over - it may be more useful than I thought. With those sorts of data rates, plus futzing time to get it all in cleaned-up DVD-burnable mode, the PC might end up reserved for only the special jobs.

Something to work on when my Topfield comes back from repair (what do I do in the meantime? )

Peter

I too only get 18Megabits per sec in turbo mode with an ostensably USB2.0 card.
This is way below USB2.0 speeds of 480Mb/s

I have never tested another USB2.0 device on my USB so I don't know if it is the computer or the topfield. So I was interesting to hear Rio compare a memory stick result.

Something definitely sucks about Topfield calling their devices USB2.0


Roger