If you have a CD-ROM CPS3 system then it should use RAM SIMMs I think. But the board only sets are as Calpis said. Just having the security cartridge won't do much good without a working CPS3 CD system or a SF3 board only set. But that's all I know about the CPS3. Too costly for my tastes and no games on it are worth it.
there are no cps3 motherboards that use ram simms, it's all proprietary flash. get another cps3 mobo if you need additional memory. keep in mind that there are 2 different types of flash simms for prg and gfx slots.
I heard that most upgrade kits came with simms anywy, so there should be a few of them laying around somewhere. To be honest cps3 is one of those systems that you have to be really committed to buy the real hardware, it's pretty unreliable and slow to change games and the games aren't great. It was nice to see them emulated though.
It has SF3 which is cheap enough and a great little game (although 3rd strike does still cost a bundle).
