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Speed Problems on Linux with QB

Posted: Sat Oct 20, 2018 11:33 pm
by BigEd
Recently upgraded to Mint 19 and QB 4.1.3. Prior I was using Mint 18.3. My internet Speeds from Speedtest.net are 113Mbps download and 12Mbps upload. I was always getting 7-9Mbps download speeds, even with 4.1.3 but now can't get over 950kbps per torrent. I can download 6-7 torrents and each will get upto an average of 800-950kbps but none over this 950kbps mark. I have everything open, full speed

So using vmware I loaded up a fresh install of mint 18.3 and updates and then a default install of QB 3.3.1
and my downloads were up where they belong in the 7Mb-9Mb speeds per torrent. Great, happy again. Now I take and update QB to 4.1.3 and the speeds are now in the 800-950kbps same as my regular desktop. Next I completely remove QB, clean up and reinstall and lock 3.3.1 and no change, still at 800-950 mark. And yep, speedtest is still on mark.

The server I'm pulling torrents from is my own server all the time. So it isn't a seeding problem on that end.

What can I be missing that would cause this? Anyone else have this problem? Driving me crazy...

Re: Speed Problems on Linux with QB

Posted: Tue Oct 23, 2018 12:59 am
by BigEd
Think I found the problem. Linux has gotten more restrictive on at least their desktop versions. I remember having an issue a year ago on a server and Rtorrent. Speed issues not up to par. So for fun and giggles I tried the same on my desktop release at home. Edit sysctl.conf and add the following lines at the end....

My speeds are back up to par, even had to slow down my QB settings to avoid it taking all my speed.

### NON DEFAULT CONFIG FROM HERE DOWN###
### IMPROVE SYSTEM MEMORY MANAGEMENT ###
### edit sysctl.conf save and issue sudo sysctl -p afterwards ###

# Increase size of file handles and inode cache
fs.file-max = 2097152

# Do less swapping
vm.swappiness = 10
vm.dirty_ratio = 60
vm.dirty_background_ratio = 2

### GENERAL NETWORK SECURITY OPTIONS ###

# Number of times SYNACKs for passive TCP connection.
net.ipv4.tcp_synack_retries = 2

# Allowed local port range
net.ipv4.ip_local_port_range = 2000 65535

# Protect Against TCP Time-Wait
net.ipv4.tcp_rfc1337 = 1

# Decrease the time default value for tcp_fin_timeout connection
net.ipv4.tcp_fin_timeout = 15

# Decrease the time default value for connections to keep alive
net.ipv4.tcp_keepalive_time = 300
net.ipv4.tcp_keepalive_probes = 5
net.ipv4.tcp_keepalive_intvl = 15

### TUNING NETWORK PERFORMANCE ###

# Default Socket Receive Buffer
net.core.rmem_default = 31457280

# Maximum Socket Receive Buffer
net.core.rmem_max = 12582912

# Default Socket Send Buffer
net.core.wmem_default = 31457280

# Maximum Socket Send Buffer
net.core.wmem_max = 12582912

# Increase number of incoming connections
net.core.somaxconn = 4096

# Increase number of incoming connections backlog
net.core.netdev_max_backlog = 65536

# Increase the maximum amount of option memory buffers
net.core.optmem_max = 25165824

# Increase the maximum total buffer-space allocatable
# This is measured in units of pages (4096 bytes)
net.ipv4.tcp_mem = 65536 131072 262144
net.ipv4.udp_mem = 65536 131072 262144

# Increase the read-buffer space allocatable
net.ipv4.tcp_rmem = 40960 12582912 62914560
net.ipv4.udp_rmem_min = 16384

# Increase the write-buffer-space allocatable
net.ipv4.tcp_wmem = 40960 12582912 62914560
#net.ipv4.tcp_wmem = 8192 65536 16777216
net.ipv4.udp_wmem_min = 16384

# Increase the tcp-time-wait buckets pool size to prevent simple DOS attacks
net.ipv4.tcp_max_tw_buckets = 1440000
#net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1

Re: Speed Problems on Linux with QB

Posted: Sat Aug 03, 2019 8:04 am
by xecpadenu
Thank you for this. Made significant improvements for me on my setup: i9-9900k, 32GB DDR4-3200, and 1Gb/s/1Gb/s with 1000+ seeds.