I avoided this problem by doing a clean install. I used the following article to prepare a removable drive for booting a Mavericks installation.
and another related one.
If you don’t want to go through all this then you can try disabling indexing which is what I did after installing Mavericks just to be sure.
The following command is for disabling Indexing but it should leave Spotlight active so you can still search sudo mdutil -a -i off
I always disable indexing even with Windows after I diagnosed a friends machine and saw that Windows7 indexing was using 30-50% of her CPU usage which was all devoted to keeping her HD constantly busy. Indexing seems to be far more trouble than it’s worth.
If you disable indexing, you can still search your HD but it takes longer because the results are not pre-cached from the index searching.
There is another problem with Mavericks which can cause similar issues and the following article also shows how to deal with this. This one is related to the System Stats utility. http://osxdaily.com/2014/02/27/systemstats-cpu-use-slow-mac-os-x/
BTW, the people at osxdaily.com are really on top of things and they write straight-forward articles that are easy to understand so you may want to browse through the site and see what else there is which may be of use to you.
best wishes, Marc.