I'm not sure to be into the right forum.
To follow this french article:
The max latency is very important. I have noted under linux: correct FPS but some time a big latency/FPS slow down. Same for my hdd.
Phoronix should include in their test the latency check for graphic card (I have have big slow down when I'm playing and kopete/skype open a window). And for hdd when you you have file copy in progress in graphic (KDE/Gnome?) and you try open an application (like chrome, with multiple small file to open).
I have sometime latency when I write into kwrite... about 500~3000ms after I have press the key is displayed on my screen.