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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Re: SFTP - high CPU while copying

Post by *remittor » 2019-10-17, 07:52 UTC

I just did a little testing. The tested speed transferred a huge file between two computers that are connected by a 1 Gbit network (Win7 x64 / Ubuntu 14).
Tested the transfer in the following programs:
1) TotalCmd 9.22a x64 + SFTP 2.50
2) TotalCmd 9.22a x64 + SFTP4TC 1.4.67.4
3) WinSCP 5.15.5
4) Bitvise SSH Client 7.15

Results:

Code: Select all

TotalCmd+SFTP (SFTP mode)   1100 KB/s   ( 50% load 1 CPU core)
TotalCmd+SFTP (SCP mode)    3200 KB/s   ( 50% load 1 CPU core)
TotalCmd+SFTP4TC           25000 KB/s   (100% load 1 CPU core)
WinSCP (SFTP mode)           680 KB/s   (100% load 1 CPU core)
WinSCP (SCP mode)          22000 KB/s   (100% load 1 CPU core)
Bitvise (SFTP mode)        40000 KB/s   (100% load 1 CPU core)

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yyang
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Re: SFTP - high CPU while copying

Post by *yyang » 2019-10-18, 03:35 UTC

Same experience here for quite a long time... SCP data exchange with any server is CPU intensive, like 100% on one core. In contrast, with FileZilla the CPU usage is almost negligible. But I love the flexible side-by-side sync UI too much. :)
#147523

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Re: SFTP - high CPU while copying

Post by *remittor » 2019-10-18, 07:03 UTC

yyang wrote:
2019-10-18, 03:35 UTC
But I love the flexible side-by-side sync UI too much. :)
try Bitvise SSH client

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