This article shows several ways to optimize uTorrents performance, maximizing download speeds and improving connectivity. See also the article "Speed" for a lot of more tips, tools and hacks to improve your internet connection speed.
For information about the other advanced settings that aren't listed here, see the uTorrent Help File (.zip).
UPnP Port Mapping should be enabled - uTorrent then sets port forwarding for ports it needs automatically via Universal Plug&Play (if supported by your router).
NAT_PMP Port Mapping should be disabled - it mostly doesn't work right and is only an alternative for UPnP Port Mapping.
Windows Firewall exception should only be enabled if your windows firewall is active (which is NOT recommended).
Port for incoming connections - Port choice is important for your connectivity. You should choose a port higher than 50000 to prevent conflicts with other applications
Limit Transport overhead should be disabled if you only have a limited upload bandwidth. Play around with it and check the speed difference.
Limit uTP-connections usually should be disabled, except if you have deactivated your halfopen limit (see advanced setting "net.max_halfopen" and article Speed).
Use additional upload slots should be enabled to allow more people to download from you, allowing also you to download more from them.
Protocol encryption should be set to "enabled". If you're not using a VPN service, set this to "forced" for more security.
Everything else should be left to default or doesn't give any advantage.
uTorrent advanced settings (Tab "Advanced")
- bt.allow_same_ip
Meaning: Enabling this option allows multiple incoming connections from the same IP address. This option affects a single torrent job at a time, so you can still have the same IP address connect to you on different torrent swarms.
Recommendation: Enabling this option possibly increases download speeds because it allows multiple connections from one IP: - bt.connect_speed
Meaning: This option specifies the number of connections µTorrent should allow to be attempted and/or established each second, whether the connections use uTP or TCP.
Recommendation: Set this value higher speeds up connecting to seeds+peers. I've had good result with 22-77; of course it depends on your internet connection. - bt.enable_tracker
Meaning: Enabling this option enables the rudimentary tracker embedded in µTorrent. If you wish to use this tracker, the URL is located at http://IP:port/announce, where IP is your WAN IP address, and port is the port µTorrent is listening on (or the alternative listening port if set and enabled). If you use a dynamic DNS service, your domain may be used instead of your IP address. The embedded tracker allows tracking of external .torrent files, and provides no way to limit them. There is no interface for viewing the .torrent files that are tracked. It is imperative that µTorrent is able to listen for incoming connections for this feature to work properly, so you have to make sure you have completely forwarded your ports in order to use the embedded tracker.
Recommendation: May give you more peers to download from. - bt.multiscrape
Meaning: Enabling this option allows µTorrent to send multiple hashes each time it scrapes a tracker, which is more efficient than sending one hash at a time. In most circumstances, this option should not need to be disabled, as µTorrent will fall back to single scraping if it detects that the tracker does not support multi-scraping.
Recommendation: Should always be enabled to increase amount of peers. - bt.no_connect_to services
Meaning: This option tells µTorrent not to connect to peers using ports specified in bt.no_connect_to_services_list as their listening ports. This stops firewalls from complaining about µTorrent trying to send an e-mail.
Recommendation: Disabling this option possibly increases download speed if some peer uses the ports listed in bt.no_connect_to_services_list in his BitTorrent client. - bt.ratelimit_tcp_only
Meaning: Enabling this option tells µTorrent to limit the upload and download rates for TCP connections based on information received over the uTP transport rather than using static global rate limits. This option is ignored if bt.tcp_rate_control is disabled.
Recommendation: Should be disabled to achieve max speed. - bt.scrape_stopped
Meaning: Enabling this option allows µTorrent to get seed and peer counts for torrent jobs that are stopped.
Recommendation: Should be disabled, else it will reduce speed because of too much connections. - bt.send_have_to_seed
Meaning: Enabling this option tells µTorrent to send a message to other seeds indicating how many pieces you currently have.
Recommendation: Depends on how much percent of a torrent is already downloaded, it may improve speeds. If you just have a little part finished, it improves speeds. If you almost have a torrent finished, it will reduce speeds ("Endgame mode") - bt.set_sockbuf
Meaning: This debugging option allows µTorrent to automatically detect the TCP buffer size periodically (so_sndbuf) and adjust it based on your upload speed. It does not adjust based on latency.
Recommendation: The recommendation for this setting depends on your internet connection. I have good results with it set to "false". - bt.tcp_rate_control
Meaning: Enabling this option tells µTorrent to use information from the uTP transport as hints for limiting TCP transfer rates.
Recommendation: Should be disabled, or else speeds will be limited. - bt.transp_disposition
Meaning: This option controls µTorrent's level of bias towards using TCP or uTP for transporting data (assuming the peer at the other end of the connection supports both transport protocols).
Recommendation: Set this to 255 to allow all kinds of connections. - bt_use_ban_ratio
Meaning: This option tells µTorrent to use bt.ban_ratio to decide when a peer gets banned after it has exceeded bt.ban_threshold.
Recommendation: Setting this to false might increase speeds because it allows downloading from peers which otherwise you could not download from. - bt.use_rangeblock
Meaning: When enabled, µTorrent will automatically attempt to determine whether an entire range of IP addresses should be banned for sending hashfailed pieces rather than banning individual IPs one at a time. When µTorrent bans 4 IPs from the same /24 CIDR block, it will ban the entire /24 CIDR block. When µTorrent bans 4 CIDR blocks of size /24 from the same /16 CIDR block, it will ban the entire /16 CIDR block. When µTorrent bans 4 CIDR blocks of size /16 from the same /8 CIDR block, it will ban the entire /8 CIDR block.
Recommendation: Set this to false, or else you will ban good peers. - dht.rate
Meaning: This option specifies the amount of bandwidth that DHT will use. The default value, -1, tells µTorrent to manage the bandwidth usage automatically based on your maximum upload rate. The automatic value is obtained by dividing your maximum upload rate by 16. This value is interpreted in bytes per second, so please enter it as such.
Recommendation: This setting can be left to default ("-1"). If your upload bandwidth is high enough, you can set this to 4096, which may give more peers through DHT. - ipfilter.enable
Meaning: This option, when enabled, tells µTorrent to load ipfilter.dat and apply the rules on connections established after it is loaded. Note that disabling and re-enabling this option will force µTorrent to reload ipfilter.dat.
Recommendation: Disabling this can improve speeds because it allows connections to peers that otherwise would be blocked. For security reasons you should enable it, but only if you have a IPFILTER.DAT file installed. - isp.bep22
Meaning: This option enables Local Tracker Discovery, allowing µTorrent to attempt to discover ISP-local trackers via a series of reverse DNS lookups. The ISP-local tracker can return a list of peers and caches (most likely ISP-local). Note that if your ISP is known to interfere with BitTorrent traffic, careful consideration should be taken in deciding to enable this option. Announcing to a ISP-hosted tracker indicates to the ISP that you are using BitTorrent, and as such, can make it easier for the ISP to interfere. Private torrent jobs are not announced to local trackers.
Recommendation: Should be disabled. Can possibly get you more peers, but in reality that won't happen. - net.calc_overhead
Meaning: If enabled, this option tells µTorrent to include communication overhead between you and other peers in the transfer rate calculations.
Recommendation: Enable this to prevent uTorrent from using too much upload bandwidth. May improve download speed. - net.calc_tracker_overhead
Meaning: If enabled, this option tells µTorrent to include communication overhead between you and the tracker in the transfer rate calculations.
Recommendation: Enable this to prevent uTorrent from using too much upload bandwidth. May improve download speed. - net.disable_incoming_ipv6
Meaning: If enabled, this option tells µTorrent to not use IPv6.
Recommendation: Set this to false to allow downloads from IPv6 peers. Can improve speeds. - net.discoverable
Meaning: If enabled, this option tells µTorrent to listen on one of a sequence of well-known ports for incoming connections in addition to the standard and alternative listening ports. Because the sequence of ports is well-known to applications attempting to interface with µTorrent, it allows for such applications to connect to µTorrent with less effort on the user's part.
Recommendation: Set this to true to improve connectivity. - net.max_halfopen
Meaning: This option specifies how many connections µTorrent should attempt to establish simultaneously at any given time. On systems running Windows XP with Service Pack 2 (SP2) or newer, if your TCPIP.sys file is unpatched, you should leave this option at its default value.
Recommendation: Setting this to 255 often improves speeds. - net.utp_packet_size_interval + net.utp_receive_target_delay + net.utp_target_delay
Meaning:
Recommendation: This settings can get played around with, but won't affect speed noticeable. - net.wsaevents
Meaning: This option is used for tweaking if you are experiencing odd firewall issues. Decrease the value one by one to see if it helps.
Recommendation: Setting to 150 may improve speed. - peer.disconnect_inactive
Meaning: Enabling this option tells µTorrent to disconnect from a peer that is not transferring with you after peer.disconnect_inactive_interval seconds of inactivity. A peer gets disconnected by this option only if the connection limit has been reached.
Recommendation: Set this to true or else your uTorrent will be overloaded after a while. - peer.lazy_bitfield
Meaning: Some ISPs block seeding by looking for the complete bitfield and closing the connection. When enabled, µTorrent does not send the complete bitfield, but a sample of it, so as to prevent blocking of seeding.
Recommendation: Set this to true for avoiding ISP blockings. Improves seeding, so it also improves downloading. - peer.resolve_country
Meaning: Enabling this option tells µTorrent to use an Internet database of IP addresses (a DNSBL) to determine a peer's country. Even if the settings directory contains flags.conf and flags.bmp, this option will take precedence, and the internal flag images will be used instead.
Recommendation: Should be deactivated to save some traceroutes, possibly increasing speed.
For information about the other advanced settings that aren't listed here, see the uTorrent Help File (.zip).
Tab "Connection"
UPnP Port Mapping should be enabled - uTorrent then sets port forwarding for ports it needs automatically via Universal Plug&Play (if supported by your router).
NAT_PMP Port Mapping should be disabled - it mostly doesn't work right and is only an alternative for UPnP Port Mapping.
Windows Firewall exception should only be enabled if your windows firewall is active (which is NOT recommended).
Port for incoming connections - Port choice is important for your connectivity. You should choose a port higher than 50000 to prevent conflicts with other applications
Tab "Bandwidth"
Limit Transport overhead should be disabled if you only have a limited upload bandwidth. Play around with it and check the speed difference.
Limit uTP-connections usually should be disabled, except if you have deactivated your halfopen limit (see advanced setting "net.max_halfopen" and article Speed).
Use additional upload slots should be enabled to allow more people to download from you, allowing also you to download more from them.
Tab "BitTorrent"
Bandwidth Management [uTP] should only be enabled if you feel that other internet applications are working slowly.Protocol encryption should be set to "enabled". If you're not using a VPN service, set this to "forced" for more security.
Everything else should be left to default or doesn't give any advantage.
uTorrent is not downloading while on VPN
If uTorrent is unable to down/upload while the VPN is connected, or you can't connect to any trackers, there are several things you should try:- Try again with VPN servers from a different area
- Switch VPN protocols between OpenVPN / PPTP / L2TP / UDP
- Enable UPnP and NAT-PMP port mapping in the uTorrent settings
- Try different ports in the uTorrent settings
- Disable all security related software on your computer, antivirus, firewall, especially the windows firewall, peerblocking tools, etc.
- Disable Secure IP Binding feature in the HMA! Pro VPN client
- Install a different uTorrent version (alpha/beta version, x64 version, etc.) -> http://forum.utorrent.com/viewforum.php?id=4
Additional
- You should try out beta and alpha versions, new versions can be found here: uTorrent announcement forum
- Apps like "uTorrent Turbo Booster", "uTorrent Ultra Accelerator" and similiar apps you may find on the web are scamware; they don't change anything. Any advantage you may notice when using those tools are placebo-effects.
- Using a too big IPFILTER.DAT or IP-Blocklist (PeerBlock) may also reduce your speed because they contain many tracker IPs and good users.
- There are hacked versions of uTorrent that may increase speeds, but I won't help you finding them because it supports leeching and damages the BitTorrent-credit-system
