My computer build is
Amd Phenom II x4 945
Asus Crosshair Formula V mobo
Corsair Vengeance 16gb 4x4 ram
KINGWIN Mach 1 1000watt power supply
ATI Raideon 4850 x2 crossfired
and right now as my hard drive i have just a 1tb 7200rpm western digital
I planing on making an ssd as my primary drive but i don't know weather or not to get just 1 512 or raid0 2 256 ssd's
The thing is i don't know if its worth the trouble of setting up a raid0 and i herd that trim isn't supported on amd based systems has anyone done a raid0 with trim on an amd based system here that can help me out? and is it that much of performance increase?
If you haven't bought any of the SSD's yet I would purchase the 512. Not only can you use trim, but if you were to RAID0 them, you would effectively double your chances of losing all of your data (all things being equal). Because all it takes is for one of the two drives to go bad to lose ALL the data on both.
If we were talking HDD's I might consider the RAID0 simply for the performance advantage. But with SATA3 SSD's you're not going to see a performance advantage with RAID0.
By the way, I have two 120 GB SSD's myself and they are in RAID0 and am happy with the setup. The reason I went with this option is because at the time I built my PC, I could only afford one 120 drive and not a 240 drive. Also, when I bought the second drive, I reinstalled Windows and chose to RAID0 just so that it would appear as 1 drive to Windows and not worry about 1 getting almost full and trying to balance what to put on each. This is another reason I say go for the 1 drive.
Something that you could do with two drives is a good RAID 5 setup if your system supports it. You could make four partitions on each drive and combine them all in RAID 5. You'd lose about 12.5% of the maximum capacity, but it'd have most of the speed of RAID 0 (greater than a single 512GB drive) and it'd have it without the reliability hit.
However, with how a 256GB drive is already so fast (at least with the high-end models), it might not be worth the work to get an even faster RAID setup. A single 512GB drive would be fast enough and would be simpler.