[Client] Mac client has Major FPS drops

In Mavericks and now the same in Yosemite, having massive FPS degrades that occur when using abilities or when other champions use abilities. This means that teamfights are almost the worst situation of all.

Particular champions have been consistently bad like Kog'Maw with dragon-lion skin. His E will cause the system to slow to a crawl, which typically you are using this to escape or to engage, and the slowdown/game lag is devastating. It's happened on Ziggs e's as well, when the other team uses Heime and he ults's. With anyone that has visually demanding effects on abilities, it seems as soon as it's cast (regardless of who is casting) the system decides to go into "I'm thinking about how to display this ability, hold on while I drop your FPS so you can't react at all, thanks for your patience."

The screen get's choppy, FPS degrades, the champions jump around screen, abilities get cast seconds too late, timing of abilities makes you miss or be in the wrong position, you get ganked when you should have got a kill. For a real-time strategy and teamwork game, it really ruins your gameplay quality regardless of your skill because it is unpredictable as to when and how long it will affect you, and what the other players are doing is a mystery as well so you find out a 3-6 seconds later how unlucky you were.

It was happening in 4_17_xxx and now even more in 4_18_xxx.

My hardware is:

iMac 27" - Mid 2011 3.4 GHz Dual Quad-Core i7 16 GB 1333 MHz DDR3 RAM AMD Radeon HD 6970M 2GB VRAM Running Yosemite now, but happened consistently on Mavericks as well Internet: 105 Mbps down / 50 Mbps up, my ping is consistently between 14-20 ms, it's never been a ping-lag issue, always FPS

I make sure that I quit every program, etc. but it is still unchanged. I have tried lowering graphics all the way to lowest settings possible, no change or actually it seems like it makes it worse to be honest; going back to medium settings, no change. Windowed and Fullscreen modes act the same.

Vertical sync, unchecked, Anti-Alias unchecked, Character Inking unchecked. I've tried every recommendation I can find without any noticeable change.

As you can see, it really is incredibly frustrating, I know I have enuf juice in my system to be able to handle this game. I have lost a lot of LP because of these moments that happen that turn the tide of the game, especially teamfights where we would have easily won except I got killed while my FPS got dropped to 5 fps for 10 seconds and basically I appeared to stand there and do nothing while getting killed.

If you need more information, please contact me. I would love to be able to help you fix this if there is anything I can do to help.