Hello,
When I try to open Gmail it loads slowly and the even after the website is visible, it is "frozen" for a bit and takes a ton of CPU for a while. After that it "cools down" and reacts normally.
I've had the same thing in the Incognito mode without any plugin or extension running.
Version 7.5.2.4000 (64-bit) 1229 on Windows 10.