SFTP - high CPU while copying

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obmana
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SFTP - high CPU while copying

Post by *obmana » 2018-09-23, 08:01 UTC

Hi,

I copy a file over SSH in local network (on raspberrypi), and CPU usage is ~50%
Image: http://i.imgur.com/p8ObBUU.png

If I pause the copying process then CPU drops.

I use latest TC.

Any ideas?

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ghisler(Author)
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Re: SFTP - high CPU while copying

Post by *ghisler(Author) » 2018-09-24, 14:42 UTC

Please use the option "SCP for transfers" in the connection settings. SFTP transfers are quite CPU intensive because they send the data in small separate packets. SCP is sending/receiving in one stream, which is both faster and less CPU intensive.
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obmana
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Re: SFTP - high CPU while copying

Post by *obmana » 2018-09-25, 17:19 UTC

SCP option is already enabled: Image: https://i.imgur.com/LqppywR.png

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Re: SFTP - high CPU while copying

Post by *obmana » 2018-09-25, 17:23 UTC

Actually disabling ZLIB compression solves the problem

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Re: SFTP - high CPU while copying

Post by *obmana » 2018-09-25, 18:11 UTC

Oh, above is not true, it just go high after is starts copying.
It's 1GB file if that matters...

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Re: SFTP - high CPU while copying

Post by *ghisler(Author) » 2018-09-26, 08:06 UTC

Strange, I don't have this problem with SCP transfers. Maybe you resumed a download? SCP doesn't support that, so TC has to revert to regular SFTP.
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olejak
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Re: SFTP - high CPU while copying

Post by *olejak » 2019-09-04, 07:51 UTC

I see the same issue with large files. I'm running 9.22a 64bit and ftp plugin version 2.50 (32 bit+64 bit) on Windows 10.

When I copy a file Total Commander uses 20-25% CPU consistently on 2 cores Intel i5-6300U with HT enabled, when running SFTP and SCP. I have tried coping to mutilple hosts running Linux, FreeBSD and OpenBSD.

When coping the same files to the same hosts using puttys scp I don't get this high CPU usage. When using WinSCP i peaks at 12% on my system and is otherwise not using very much CPU.

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