Time Machine can be a life saver - but do you really need backups every hour? I've got a big external hard drive and it really slows my Mac down when it starts its backups, always at the most inconvenient time.
Change the frequency! It's easy. There are two little applications that will let you do this, such as -
Reviews say this is very easy to use (it is, I have) but there are some warnings - if your Time Machine backup drive is not available or if Time Machine is turned off you get confusing warning messages.
Reviews - this one scores better than TimeMachineEditor, but there seem to be more problem reported.
Or, you can open Time Machine preferences and switch it to Off - but remember to switch it on again at intervals.