Issue activity log

2008-02-28 10:18 Created Slow file transfers
Component Core
Severity Enhancement
Comment Many users report WinSCP not to utilize all available bandwidth.

This topic is discussed in FAQ:
https://winscp.net/eng/docs/faq_slow
2008-02-28 10:26 Comment Related: Issue 1, Issue 17.
Also WinSCP 4.1 will support (less secure) Arcfour cipher, which should be fast.
2008-02-28 10:52 Comment WinSCP (FAR plugin 1.5.1 base on WinSCP 3.8.2) is as fast as PSCP (8 MB/s) and SFTP (3 MB/s) (PuTTY 0.60):
https://winscp.net/forum/viewtopic.php?t=3137

WinSCP 3.8.2 is as fast on upload as SSH Secure Shell 3.2.9, but much slower on download on WinXP. On Win2K it is as fast:
https://winscp.net/forum/viewtopic.php?t=4684

Transfer rate is capped at 100KBps:
https://winscp.net/forum/viewtopic.php?t=5277
https://winscp.net/forum/viewtopic.php?t=5313

SCP significantly faster than SFTP:
https://winscp.net/forum/viewtopic.php?t=5096

https://winscp.net/forum/viewtopic.php?t=2455

PuTTY 0.59 much faster than 0.58:
https://winscp.net/forum/viewtopic.php?p=14104#14104
2009-03-02 08:22 Comment 4.2.1 almost twice as fast as 4.1.8 on Windows Vista:
https://winscp.net/forum/viewtopic.php?t=6614
2009-07-03 08:13 Comment Suggestion for fixing network speed after installing SP2 for Vista:
https://winscp.net/forum/viewtopic.php?p=24994#24994
2009-08-19 08:39 Comment Fixing network speed in WinXP:
https://winscp.net/forum/viewtopic.php?p=25801#25801
2010-10-16 20:46 Comment It has been suggested by ultramage that increasing SSH socket buffer size may instead transfer speed. See Issue 615.
2011-11-11 09:35 Comment Issue 615 has been rolled back by Issue 677 as some users were having problems with it.
The fix was reintroduced by Issue 690, with option to disable it, in WinSCP 5.0.3.
2016-05-17 09:33 Comment Issue 787: WinSCP 5.0.6: When Optimize connection buffer size is enabled, also FTP socket internal buffer size is increased.
Comment Issue 1141: WinSCP 5.2.2: Increase local SSH send buffer to improve performance
Comment Issue 1273: WinSCP 5.7: Size of connection receiving buffer increased.
2016-05-17 09:34 Comment WinSCP 5.8: Improved transfer speed:
– with SFTP and SCP protocols when CPU is limiting factor.
– with SFTP on high latency connections Issue 1295
Implemented in 5.8
Resolution FIXED
Status RESOLVED
2016-05-19 09:21 Comment 5.8.3: Dynamically increase TCP send buffer on fast connections.
2018-01-11 09:09 Comment https://winscp.net/forum/viewtopic.php?t=25705
2019-06-14 09:13 Comment S3 specific entry: Issue 1732
2019-07-21 10:40 Comment Issue 1769: Hardware accelerated AES (AES-NI)
2022-10-03 10:45 Comment WinSCP 4.2.1 almost twice as fast as WinSCP 4.1.8 on Windows Vista:·  https://winscp.net/forum/viewtopic.php?t=6614
Comment WinSCP (FAR plugin 1.5.1 basebased on WinSCP 3.8.2) is as fast as PSCP (8 MB/s) and SFTP (3 MB/s) (PuTTY 0.60):·  https://winscp.net/forum/viewtopic.php?t=3137·  ·  WinSCP 3.8.2 is as fast on upload as SSH Secure Shell 3.2.9, but much slower on download on WinXP. On Win2K it is as fast:·  https://winscp.net/forum/viewtopic.php?t=4684·  ·  Transfer rate is capped at 100KBps:·  https://winscp.net/forum/viewtopic.php?t=5277·  https://winscp.net/forum/viewtopic.php?t=5313·  ·  SCP significantly faster than SFTP:·  https://winscp.net/forum/viewtopic.php?t=5096·  ·  https://winscp.net/forum/viewtopic.php?t=2455·  ·  PuTTY 0.59 much faster than 0.58:·  https://winscp.net/forum/viewtopic.php?p=14104#14104· 
2022-10-03 10:46 Comment Bug 615 has been rolled back by Bug 677 as some users were having problems with it.·  The fix was reintroduced by Bug 690, with option to disable it, in WinSCP 5.0.3.· 
Comment Bug 787: WinSCP 5.0.6: When //Optimize connection buffer size// is enabled, also FTP socket internal buffer size is increased.
Comment Bug 1141: WinSCP 5.2.2: Increase local SSH send buffer to improve performance
Comment Bug 1273: WinSCP 5.7: Size of connection receiving buffer increased.
Comment WinSCP 5.8: Improved transfer speed:·  - with SFTP and SCP protocols when CPU is limiting factor.·  - with SFTP on high latency connections Bug 1295
Comment WinSCP 5.8.3: Dynamically increase TCP send buffer on fast connections.
2022-10-03 10:47 Comment WinSCP (FAR plugin 1.5.1 based on WinSCP 3.8.2) is as fast as PSCP (8 MB/s) and SFTP (3 MB/s) (PuTTY 0.60):   https://winscp.net/forum/viewtopic.php?t=3137   ---   WinSCP 3.8.2 is as fast on upload as SSH Secure Shell 3.2.9, but much slower on download on WinXP. On Win2K it is as fast:   https://winscp.net/forum/viewtopic.php?t=4684     Transfer rate is capped at 100KBps:   https://winscp.net/forum/viewtopic.php?t=5277   https://winscp.net/forum/viewtopic.php?t=5313     SCP significantly faster than SFTP:   https://winscp.net/forum/viewtopic.php?t=5096     https://winscp.net/forum/viewtopic.php?t=2455     PuTTY 0.59 much faster than 0.58:   https://winscp.net/forum/viewtopic.php?p=14104#14104  
Comment WinSCP (FAR plugin 1.5.1 based on WinSCP 3.8.2) is as fast as PSCP (8 MB/s) and SFTP (3 MB/s) (PuTTY 0.60):   https://winscp.net/forum/viewtopic.php?t=3137   ----   WinSCP 3.8.2 is as fast on upload as SSH Secure Shell 3.2.9, but much slower on download on WinXP. On Win2K it is as fast:   https://winscp.net/forum/viewtopic.php?t=4684     Transfer rate is capped at 100KBps:   https://winscp.net/forum/viewtopic.php?t=5277   https://winscp.net/forum/viewtopic.php?t=5313     SCP significantly faster than SFTP:   https://winscp.net/forum/viewtopic.php?t=5096     https://winscp.net/forum/viewtopic.php?t=2455     PuTTY 0.59 much faster than 0.58:   https://winscp.net/forum/viewtopic.php?p=14104#14104  
Comment WinSCP (FAR plugin 1.5.1 based on WinSCP 3.8.2) is as fast as PSCP (8 MB/s) and SFTP (3 MB/s) (PuTTY 0.60):   https://winscp.net/forum/viewtopic.php?t=3137   ----   WinSCP 3.8.2 is as fast on upload as SSH Secure Shell 3.2.9, but much slower on download on WinXP. On Win2K it is as fast:   https://winscp.net/forum/viewtopic.php?t=4684   ----   Transfer rate is capped at 100KBps:   https://winscp.net/forum/viewtopic.php?t=5277   https://winscp.net/forum/viewtopic.php?t=5313   ----   SCP significantly faster than SFTP:   https://winscp.net/forum/viewtopic.php?t=5096   ----   https://winscp.net/forum/viewtopic.php?t=2455   ----   PuTTY 0.59 much faster than 0.58:   https://winscp.net/forum/viewtopic.php?p=14104#14104  
Comment ReleatedReleted: Bug #1, Bug #17.·  Also WinSCP 4.1 will support (less secure) Arcfour cipher, which should be fast.
2022-10-03 10:48 Comment WinSCP (FAR plugin 1.5.1 based on WinSCP 3.8.2) is as fast as PSCP (8 MB/s) and SFTP (3 MB/s) (PuTTY 0.60):   https://winscp.net/forum/viewtopic.php?t=3137   ----   WinSCP 3.8.2 is as fast on upload as SSH Secure Shell 3.2.9, but much slower on download on WinXP. On Win2K it is as fast:   https://winscp.net/forum/viewtopic.php?t=4684   ----   Transfer rate is capped at 100KBps:   https://winscp.net/forum/viewtopic.php?t=5277   https://winscp.net/forum/viewtopic.php?t=5313   ----   SCP significantly faster than SFTP:   https://winscp.net/forum/viewtopic.php?t=5096   ----   https://winscp.net/forum/viewtopic.php?t=2455   ----   PuTTY 0.59 much faster than 0.58:   https://winscp.net/forum/viewtopic.php?pt=141044366#14104  
Comment Suggestion for fixing network speed after installing SP2 for Vista:·  https://winscp.net/forum/viewtopic.php?pt=249946905#24994
Comment Fixing network speed in WinXP:·  https://winscp.net/forum/viewtopic.php?pt=258015277#25801
2022-10-03 10:49 Comment Fixing network speed in WinXPWindows XP:   https://winscp.net/forum/viewtopic.php?t=5277#25801
Comment ReletedRelated: Bug 1, Bug 17.   Also WinSCP 4.1 will support (less secure) Arcfour cipher, which should be fast.
2022-10-03 10:50 Comment Many users report WinSCP not to utilize all available bandwidth.·  ----   This topic is discussed in FAQ:·  https://winscp.net/eng/docs/faq_slow