Have been wondering do we(Garena players), aware of this issue. Many in NA, Euro or whatever other LoL servers are aware of this as they already have countless of FPS complaint threads in their forums.
As far as many of them have been sticking with a single major thread of this problem: http://na.leagueoflegends.com/board/....php?t=1150758
Basically, this has nothing to do with your PC(not those low specs PC). Assuming you are having a powerful or an average PC with good graphic cards and high RAM etc, but experiencing such problem isn't your PC's fault. I am trying to say, many of LoL players tend upgrade and upgrade their PC by having the thoughts of their PC isn't good enough as can be seen in NA/Euro forums after some patches(Riven, Fizz or Viktor patches). Some have been reinstalling, updating graphic cards, directX drivers and so on. All these have nothing to do with the FPS issues mostly if you already tried. Only some.
However, certain FPS issues can be solved, for such if your Virtual Memory setting is wrong, too many files eats up your PC space or by re-installing your LoL client.exe etc.. I can try put up some of the links for these problems here if needed after some time.
What am I doing while having such problems? :
To be brief, I find that mostly this Riot game technical issues are due to some of your 'Champions' animation and some bugs affecting textures/sounds/effects to be loaded properly. There's more too. Correct me if I am wrong.
Like what I said above this sentence, many of my AD carry champions or something like Akali have been affected for some reasons.(I know by saying this doesn't make sense, but it seems so to me and some other players)
But, doesn't happen to me when I tried to play Support, AP ranged, typical top laning champions or melee AP Mordekaiser. Still, I find 15% of the time with my so-called FPS issues champions, I do not have FPS issues. Probably this 15% of the time, it functioned properly? That's absurd.
So, it's fortunate for me I can play all 4 roles in this game except Jungling. I do fine in AD carry(have to retire) and support roles.
Off-topic/Little tips here: Top laners mostly requires high experiences as there's too many typical picks at top lanes including how knowledgible are you about top lane counter picks(putting aside game play skills).
[To say, try not simply try any other roles to throw someone else's game. I lose top lane for few times in elo games.]
I am not trying to make LoL community to stay after having this problem(many have refused to play this game/quitted after this problem occured). That's their/your choices. I am here to promote some awareness and alternatively telling LoL community can actually play some other Champions that aren't buggy for your client.
Lastly, I'd be obliged if I am allowed to bump this thread for some awareness. Or maybe I don't have to.
Thank you for reading.
Special Notes: Ping latency doesn't have anything to do with FPS performance.