[FFmpeg-user] Windows 10, ffmpeg concat/demux is slow... part 2

Carlos E. R. robin.listas at telefonica.net
Mon Nov 13 12:07:24 EET 2017

Hash: SHA1

On Sunday, 2017-11-12 at 17:17 -0000, Kevin Duffey wrote:

>> back then you have been asked if you had turned off all security 
>> monitoring for the target folder, such as Windows Defender, to which 
>> you haven't replied. ffmpeg is per se not a signed application, which 
>> could make utilities like such suspect there is something happening 
>> they should keep tracking.
> Sorry.. trying to figure out this bottom post thing.. cant seem to get 
> the quote or > thing working yet.

> I dont recall reading that option in a reply previously, but that is 
> interesting. I am not sure how to check for that, I can figure it out I 
> am sure. However, I would guess it is not an issue. I typically turn off 
> that stuff on my machines as I have a pretty decent hardware firewall in 
> place at my router which is Unifi/Ubiquiti hardware. Doesnt mean it may 
> not be an issue.

> In reply to another post.. using Task Manager to see disk usage.. I am 
> currently copying a 300GB DNxHR video from the SSD over USB3.1 to my 
> local internal HD. The copy speed indicates 40MB/s, in Task Manager, it 
> shows a bit over 80MB/s, which I assume accounts for the read from the 
> drive and the write to the drive... not sure though.  So this strikes me 
> as one problem. USB 3 is 5Gb/s. Or about 500MB/s.

An internal rotating platter disk should get a speed of about 80..120 

USB 2.0 has a speed of 480 Mbit/s, so you could get a speed of about 
40MB/s, max 48MB/s, which is similar to what you are indeed getting.

Another limiting factor is that continuous write speed on SSD devices can 
be slow on older or cheaper models. To make sure, you could attach a 
rotating USB3 disk and try. Or attach your USB3 SSD disk to other 
computers and try, to find out what is the limiting factor.

If you were using Linux, I'd suggest:

  hdparm -tT /dev/sdXY

to test the raw device speed (read). There must be applications in Windows 
to do similar tests, but I can't say which.

> As one of the drives 
> is an SSD.. this seems ridiculous to me that it is basically moving at 
> USB2 speeds. At the very least, as it is over a USB 3.1 gen 2, 10Gb/s 
> wire... it should be much much faster than this. So now I am left 
> wondering why my system is super slow at copying files. Is there some 
> configuration in Windows 10 that has to be enabled to allow fast 
> copying?

I don't know. In the case of the external disk above it seems a hardware 
limitation. Either the disk or the USB3 interface of the disk or the 

- -- 
        Carlos E. R.
        (from openSUSE 42.2 x86_64 "Malachite" at Telcontar)
Version: GnuPG v2


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