µTorrent is a peer-to-peer download utility. Peer-to-peer, or P2P, is the process of connecting users directly via an application. µTorrent allows users to obtain files from other users without having to download from external servers or file hosts. The speed at which files are downloaded in P2P can be astonishing, but it can also hog vast amounts of your computer's CPU. Reducing the CPU usage of µTorrent is done by limiting the max download and upload speeds of a torrent, and by limiting the number of peers µTorrent connects to.
Open µTorrent and click the "Options" link near the top of the window. Select "Preferences."Click "Bandwidth."
Record the numbers entered into the "Maximum Upload Rate," "Maximum Download Rate," and "Number of Connections" fields. Recording these numbers allows you to return the settings to normal levels later.
Change the number under "Maximum Upload Rate" to at most 100 kilobytes per second. This number indicates the amount of data that can be uploaded by µTorrent to other users at one time.
Change the "Maximum Download Rate" entry to a number between 100 and 300 kilobytes per second. This number represents the amount of data that can be downloaded to your system at one time.
Reduce the entry in the "Global maximum number of connections" field in the "Number of Connections" section to at least 100. Leave "Maximum number of connected peers per torrent" at its default value. Reduce the "Maximum number of torrent upload slots" to at least four. Click "OK" to save the changes. High numbers in these settings are the major cause for µTorrent high CPU usage.
Another easy way to reduce µTorrent CPU usage is to only have one torrent active at a time.