Very CPU usage

[Jac]

On any operation other than idling, CPU usage is very high, up to 100%, particularly when deleting books - which can take a VERY long time. Disabling my antivirus (Kaspersky) helps - CPU usage still goes to 100% but the deleting is much faster. With Kaspersky disabled,CPU usage will drop back to about 1% after deletion is complete, however if Kaspersky is not disabled, CPU remains high - 50 to 100% at all times until calibre is stopped. Additionally, multiple instances of calibre-parallel (up to 6) are likely to be running, and once started, do not seem to stop until calibre is stopped. I find worrying to have to disable antivirus protection to effectively use your program and that there seems to be a new update every 2 or 3 days.'

[kovidgoyal]

There is a new update every week. There has been for two years, that is the way calibre is developed. As for Kaspersky, get a better antivirus solution.