Recordings break up on Humax Freesat

[joddle]

Agg - thought I had this sorted by seems not. On Friday I recorded two consecutive programmes from the same BBC1 channel, Beyond Paradise then Death in Paradise . The second has recorded perfectly by the first breaks up all the time! Now I am confused. Why shodl that be? I am now going to try another brand new ssd in yet another caddy to see if that makes any difference but any other suggestions welcome. Or would I be better using a mechanical HDD?

 

[ozumo]

You could connect the SSDs & caddies to a computer and run a read/write speed test.

Just a thought - does the Humax have instant-rewind? If yes it will be constantly writing to the USB and may even be recording the same programme twice - the recorded file and the instant-rewind buffer. This would require double the write speed so disabling instant-rewind should help, more-so if it is reading from the buffer at the same time.

 

[joddle]

But why has one recorded fine and the other not - the programmes were actually back to back!

 

[ozumo]

But why has one recorded fine and the other not - the programmes were actually back to back!

Don't know. Maybe the first programme was broadcast at a higher bitrate? Or the caddy/SSD/receiver USB controller is a bit flakey? Do a speed test, if the write speeds are consistently above what BBC HD broadcasts at then it's not the caddy/SSD that's the problem.

 

[Satspot]

Do bear in mind all the chopping and changing going on with the BBC channels at the moment. Try the same test, programme recording back to back on any other HD channel other than the BBC and see what results it yields.

 

[joddle]

I will try another back to back Also am going to try a dedicated HDD instead of a SSD so no caddy just the drive!

 

[joddle]

Now I am a bit mystified. I have made a new recording using an old external USB HDD and guess what - no breakup or any problems at all !!! Why is an old mechanical drive seemingly far better then a much more modern SSD? Anyway it works so I will continue to use it.

 

[ozumo]

Have you tested and compared the sustained write speeds of the SSD vs HDD?

 

[joddle]

Have you tested and compared the sustained write speeds of the SSD vs HDD?

Not sure how to do that - is there some simple freeware available for that? if so what would be recommended?

 

[ozumo]

In Windows type CMD in the taskbar search box and then click Run as administrator. Then in the command line type:

winsat disk -drive X:

Change X to the letter of the drive you want to test and press enter.

 

[joddle]

This is the result - does it show anything?
HDD
Dshow Video Encode Time 0.00000 s
Dshow Video Decode Time 0.00000 s
Media Foundation Decode Time 0.00000 s
Disk Random 16.0 Read 0.98 MB/s 2.9
Disk Sequential 64.0 Read 39.95 MB/s 4.9
Disk Sequential 64.0 Write 38.54 MB/s 4.9
Average Read Time with Sequential Writes 9.931 ms 4.5
Latency: 95th Percentile 24.660 ms 4.2
Latency: Maximum 228.947 ms 7.2
Average Read Time with Random Writes 11.950 ms 4.0

SSD
Dshow Video Encode Time 0.00000 s
Dshow Video Decode Time 0.00000 s
Media Foundation Decode Time 0.00000 s
Disk Random 16.0 Read 13.68 MB/s 5.6
Disk Sequential 64.0 Read 39.48 MB/s 4.9
Disk Sequential 64.0 Write 37.80 MB/s 4.9
Average Read Time with Sequential Writes 2.093 ms 6.9
Latency: 95th Percentile 8.272 ms 5.9
Latency: Maximum 22.636 ms 7.9
Average Read Time with Random Writes 2.250 ms 6.8

 

[ozumo]

Not really, other than a slightly slower write speed (both probably limited by USB2 connection) the SSD is better in every other aspect.

If you have single large file (the bigger the better) you could see how long it takes to copy to each drive.

 

[joddle]

Should I test again on the USB3 port?

 

[ozumo]

You could try but both write speeds are comfortably above what any Freesat HD channel broadcasts anyway.

Are you able to see the files recorded by the Humax, if so are they large single files or many small ones?

 

[joddle]

This is how the files appear on the disk

 

[ozumo]

They are large files so that's not the problem. To be honest I'm out of ideas as to why it doesn't work

 

[joddle]

Thanks for trying anyway - the very odd thing is the HDD drive I am using now which works perfectly is very old and well used so in theory should be the least suitable for this application!!! I did run the test again using a USB3 port and these are the results but still can't see why the SSD should have issues and the HDD not!!!

USB3
HDD
Dshow Video Encode Time 0.00000 s
Dshow Video Decode Time 0.00000 s
Media Foundation Decode Time 0.00000 s
Disk Random 16.0 Read 0.99 MB/s 2.9
Disk Sequential 64.0 Read 67.92 MB/s 5.9
Disk Sequential 64.0 Write 83.83 MB/s 6.3
Average Read Time with Sequential Writes 9.260 ms 4.7
Latency: 95th Percentile 22.314 ms 4.4
Latency: Maximum 271.866 ms 7.1
Average Read Time with Random Writes 10.913 ms 4.3


SSD1
Dshow Video Encode Time 0.00000 s
Dshow Video Decode Time 0.00000 s
Media Foundation Decode Time 0.00000 s
Disk Random 16.0 Read 21.45 MB/s 6.0
Disk Sequential 64.0 Read 227.31 MB/s 7.4
Disk Sequential 64.0 Write 133.51 MB/s 7.0
Average Read Time with Sequential Writes 1.781 ms 7.1
Latency: 95th Percentile 7.637 ms 6.1
Latency: Maximum 225.203 ms 7.3
Average Read Time with Random Writes 1.949 ms 6.9

 

[joddle]

I am starting to think this is something to do with the SATA interface. The SSD disks I tried were all in SATA caddies but the HDD is a discrete unit - ie was not simply an HDD in a caddy but bought as an integrated unit USB drive - but then again I am not sure if the guts use a SATA connection or some other form of interface internally

 

[ozumo]

Unless the HDD is old it will just be a SATA drive + USB adapter in a single package. If it is older then it will be an IDE drive + USB adapter.

I do have one receiver that when viewing a signal that is just above lock will break up when recording to an external SD card, presumably the SD card or its reader is sending interference down the USB cable into the receiver. This is why I asked if you have tried recording NHK World as that signal should be much stronger with it being on a Europe beam.

 

[joddle]

Unless the HDD is old it will just be a SATA drive + USB adapter in a single package. If it is older then it will be an IDE drive + USB adapter.

I do have one receiver that when viewing a signal that is just above lock will break up when recording to an external SD card, presumably the SD card or its reader is sending interference down the USB cable into the receiver. This is why I asked if you have tried recording NHK World as that signal should be much stronger with it being on a Europe beam.

Been away so sorry for not responding earlier. It only seems to occur only when recording something which was itself recorded in HD and is also being transmitted on an HD channel. Same happens on NHK world! Not surprised at that as I get very strong signals for all the HD channels with very high HQ readings as well. It seems to be something to do with differences between SSD and HDD technologies but I am dammed if I know what!! Even really old PATA HDDs in caddies work fine!!! but not any SSD I have tried so far although that all work fine recording from HD channels where the source content is not also HD.