PC-wide lag from FFXIV

[Ahielia]

Again, everything else is running fine and I'm nowhere near maximum load on any hardware.

If the GPU core is running at 10% of 1000MHz or 10% of 100MHz won't make a difference, it will be equally shit performance.
You've yet to say if the cards are actually running at normal clocks. Or do you mean "running fine" as "yes, they are running at normal clocks"?
In which case I apologise, I'm used to talking to people who are basically technologically illiterate on tech support forums.

I had issues with my Fermi cards (560Ti) were they would be stuck in 2d mode (~1/10th or less of max speed) when I exited some programs (most notably F@H), causing abysmal FPS. I've yet to encounter this on my 680s though.

[Kaaltet]

If the GPU core is running at 10% of 1000MHz or 10% of 100MHz won't make a difference, it will be equally shit performance.
You've yet to say if the cards are actually running at normal clocks. Or do you mean "running fine" as "yes, they are running at normal clocks"?
In which case I apologise, I'm used to talking to people who are basically technologically illiterate on tech support forums.

I had issues with my Fermi cards (560Ti) were they would be stuck in 2d mode (~1/10th or less of max speed) when I exited some programs (most notably F@H), causing abysmal FPS. I've yet to encounter this on my 680s though.

Stock clocks on everything. No overclocking. 1072Mhz on the GPU with load never exceeding 55%-60%, even when the client is lagging. The CPU sits at about 3500Mhz with FFXIV running, and monitors have it running at 10% load at most, even when the client is lagging.