Actually, it would be interesting to see perf stats.
Both the iso & the game directory on internal sata
vs.
iso on ntfs usb + game directory on internal sata..
Perf differences must vary from game to game as well...
That could be very interesting, i never saw a serious comparison well made to clear all doubts
This is why i said that "technically" SATA is faster than USB, because i dont know if there is something slowing down the speeds... but initially sata should win usb
Another comparison i would like to see is the speeds loading a backup from a USB flash stick... but this needs to be made with a very good flash stick (with high read speeds.... the write speeds doesnt matters)
Ive seen some webs with huge lists of flash sticks performance, so by knowing the brand/model we could be sure that flash stick is really "squeezing" the USB speeds to the max
For some time i was considering buying a flash stick and dedicate it to the PS3
For the capacity initially i was thinking in 50GB because a PS3 bluray is limited to 50GB capacity... so in the worst scenario posible i could store 1 game in it
In the practise... the biggest game i know from PS3 library if i remember right was killzone3 with 40GB... but is because it have around 12gb of videos, and are duplicated for "stereoscopic 3D" TVs (so 24 gb of videos in total and you are never going to watch one set of them)
So... yeah, there are many games that worths to be "ripped" (to remove game files and make them smaller)
In the practise with a flash stick of 32gb should be enought to hold one game (in the worst scenario), or several