Will MacBook 6.1(late 2009) run?

Question

macbook

Hello, not so long ago I exchanged my laptop (i5 2.5GHz, 6GB RAM) for a macbook (C2D 2.4GHz, 8GB RAM, OSX 10.10.4). Installed the necessary programs, connected to mail accounts. Began to notice podlagivanie interface. On some sites, the scroll slows down, when switching between tables - 19-20 frames per second is animated. If you click on an application in the dock, the window of which is open on another desktop, you get a slightly more buggy transition. Also, when the MissionControl is displayed, all windows take their places a little slowing down .. In applications, everything seems to be fine (+ in safari sometimes lags when opening the panel with address bar bookmarks, well, although the interface is really heavy in it anyway), although maybe I just don’t I know how, ideally, these applications on a poppy should work. It's scary to think what will happen with the release of El Capitan...
Actually the question itself is the end? Will the next updates finally kill the performance of the old C2D or will there be some bright future in terms of optimization?
And another small question - is it normal that with 8 gigs of RAM and an open safari + Mail + PHPStorm + iMessage already 74% is occupied (by the way, with the closing of the storm and safari, the picture does not change much) ??
PS: exchanged -> installed Yosemite. Mavericks did not use - can my fate settle on it and live to see the next poppy?
Thanks to everyone who read to the end! (:

Answer 1

In El Capitan , everything will be chiki-farts . Everything was very much optimized there in comparison with Yosemite