sftp speed drops cpu related?

I'm starting to notice any spike in CPU% will instantly drop my speeds. If I close down some apps and wait, speed will climb up to normal ~70/MBs. As soon as I launch a browser it will drop to about 10–14, then slowly climb back up. The real problem is if apps are using a small bit of CPU like just 10% – watching a video, or a game, the speed will remain slow even tho my CPU is not maxed out total could be 15–20%.

This does not happen with other apps like usenet or Steam. My speed remains fast no matter what I'm doing on the computer. I use Windows 10 pro and have a 7th gen i7 CPU. I don't know what other relevant information would be needed. I found the post about disabling 'optimize connection buffer size', but mine already is. I tried a couple different WinSCP versions but currently using the 6.4 beta.

Please post complete session log file and corresponding exact times when the CPU usage changed.

The whole logfile is too personal. I feel comfortable showing the end here. I did get it to fluctuate a couple times but never made it to 70MBs only about 45 and getting it to drop to 15 opening chrome.

[quote]. 2024-12-17 12:45:09.713 [Background 3] Startup conversation with host finished.
. 2024-12-17 12:45:09.713 [Background 3] Adding a parallel transfer to the transfer started on the connection "Background 1"
. 2024-12-17 12:45:09.714 [Background 3] Starting transfer of "MYFILE" part 2 from 21475535530 until the EOF
. 2024-12-17 12:45:09.714 [Background 3] File: 'MYFILE' [2024-12-17T17:44:37.000Z] [32213303296]
. 2024-12-17 12:45:09.714 [Background 3] Copying "MYFILE" to local directory started.
. 2024-12-17 12:45:09.714 [Background 3] Binary transfer mode selected.
. 2024-12-17 12:45:09.714 [Background 3] Opening remote file.
> 2024-12-17 12:45:09.714 [Background 3] Type: SSH_FXP_OPEN, Size: 57, Number: 1395232771
< 2024-12-17 12:45:09.744 [Background 3] Type: SSH_FXP_STATUS, Size: 24, Number: 1395232516
. 2024-12-17 12:45:09.744 [Background 3] Discarding reserved response
< 2024-12-17 12:45:09.744 [Background 3] Type: SSH_FXP_HANDLE, Size: 13, Number: 1395232771
> 2024-12-17 12:45:09.744 [Background 3] Type: SSH_FXP_FSTAT, Size: 13, Number: 1395235848
< 2024-12-17 12:45:09.774 [Background 3] Type: SSH_FXP_ATTRS, Size: 37, Number: 1395235848
> 2024-12-17 12:45:09.774 [Background 3] Type: SSH_FXP_READ, Size: 25, Number: 1395239173
. 2024-12-17 12:45:09.901 [Background 3] Skipped 31 SSH_FXP_READ packets
< 2024-12-17 12:45:09.901 [Background 3] Type: SSH_FXP_DATA, Size: 32761, Number: 1395239173
. 2024-12-17 12:46:43.596 [Background 3] Initiating key re-exchange (too much data received)
. 2024-12-17 12:46:43.684 [Background 3] Doing NTRU Prime / Curve25519 hybrid key exchange, using hash SHA-512 (unaccelerated)
. 2024-12-17 12:46:43.867 [Background 3] Initialised AES-256 SDCTR (AES-NI accelerated) [aes256-ctr] outbound encryption
. 2024-12-17 12:46:43.867 [Background 3] Initialised HMAC-SHA-256 outbound MAC algorithm
. 2024-12-17 12:46:43.867 [Background 3] Initialised AES-256 SDCTR (AES-NI accelerated) [aes256-ctr] inbound encryption
. 2024-12-17 12:46:43.867 [Background 3] Initialised HMAC-SHA-256 inbound MAC algorithm
. 2024-12-17 12:46:53.920 [Background 1] Initiating key re-exchange (too much data received)
. 2024-12-17 12:46:54.073 [Background 1] Doing NTRU Prime / Curve25519 hybrid key exchange, using hash SHA-512 (unaccelerated)
. 2024-12-17 12:46:54.252 [Background 1] Initialised AES-256 SDCTR (AES-NI accelerated) [aes256-ctr] outbound encryption
. 2024-12-17 12:46:54.252 [Background 1] Initialised HMAC-SHA-256 outbound MAC algorithm
. 2024-12-17 12:46:54.252 [Background 1] Initialised AES-256 SDCTR (AES-NI accelerated) [aes256-ctr] inbound encryption
. 2024-12-17 12:46:54.252 [Background 1] Initialised HMAC-SHA-256 inbound MAC algorithm
. 2024-12-17 12:46:59.399 [Background 2] Initiating key re-exchange (too much data received)
. 2024-12-17 12:46:59.498 [Background 2] Doing NTRU Prime / Curve25519 hybrid key exchange, using hash SHA-512 (unaccelerated)
. 2024-12-17 12:46:59.711 [Background 2] Initialised AES-256 SDCTR (AES-NI accelerated) [aes256-ctr] outbound encryption
. 2024-12-17 12:46:59.711 [Background 2] Initialised HMAC-SHA-256 outbound MAC algorithm
. 2024-12-17 12:46:59.711 [Background 2] Initialised AES-256 SDCTR (AES-NI accelerated) [aes256-ctr] inbound encryption
. 2024-12-17 12:46:59.711 [Background 2] Initialised HMAC-SHA-256 inbound MAC algorithm
. 2024-12-17 12:47:53.420 [Background 2] Skipped 49268 SSH_FXP_READ and 49299 SSH_FXP_DATA packets
> 2024-12-17 12:47:53.420 [Background 2] Type: SSH_FXP_CLOSE, Size: 13, Number: 1432896772
. 2024-12-17 12:47:53.420 [Background 1] Skipped 47748 SSH_FXP_READ and 47779 SSH_FXP_DATA packets
> 2024-12-17 12:47:53.420 [Background 1] Type: SSH_FXP_CLOSE, Size: 13, Number: 1432897028
. 2024-12-17 12:47:53.541 [Background 3] Skipped 53497 SSH_FXP_READ and 53528 SSH_FXP_DATA packets
> 2024-12-17 12:47:53.541 [Background 3] Type: SSH_FXP_CLOSE, Size: 13, Number: 1432897284