So if i want TRIM being passed onto the C300, i have to set the C300 as SATA 0?
		
		
	 
It was just drive 1 in my example, but it can be on any port on the intel controller. Port order doesn't matter, RAID array membership does.
Your setup is:
SATA0, SATA1, SATA2 make up a RAID0 array, SATA3 is a single non raid member drive.
With such a setup SATA3 will get TRIM just fine on intel motherboards only (at the moment); any other mobo will not send it trim (only due to driver limitation).
SATA0, SATA1, SATA2 which make up a RAID0 array will not get TRIM on any controller on the market as of march 05th 2011
	
	
		
		
			As its setup right now the C300 is on SATA 3, SATA 0 1 2 being the intels in RAID 0.
...i have RST V10 installed...
		
		
	 
Then you are good to go. However if you were using an AMD motherboard, VIA mobo, etc then TRIM would not have been passed to your SSD in such a setup.
Also if you were using RST v9 or earlier then TRIM would not have been passed to your SSD. This was a driver limitation that has been resolved in intel RST10; but has yet to be resolved for other companies.
	
	
		
		
			Oh and i tried to set AHCI, and i lose RAID when i do that. 
So it needs to be set on RAID, so im lost in how to setup AHCI and have RAID working.
		
		
	 
Intel motherboards have 3 modes you can select from:
1. IDE = drives are communicated with in legacy ATA protocol; RAID is disabled. It is called IDE because of some term confusion that is likely not going to be fixed.
2. AHCI = drives are communicated with in AHCI protocol; RAID is disabled. AHCI enables NCQ and hot plugging.
3. RAID = drives are communicated with in AHCI protocol; RAID functionality is enabled.
There is no technical reason preventing a RAID mode that communicates in the legacy ATA procotol, but modern mobos don't bother with this option. If you set your mobo to RAID mode then you DO have AHCI enabled. If you are in RAID mode and have no RAID arrays it will work just like AHCI mode, only booting up your computer will take slightly longer.
It is recommended that you install windows with mobo set to RAID mode, this will make windows install the ATA, AHCI, and RAID drivers. If you install in AHCI mode you only get ATA and AHCI drivers, if you install in IDE mode it will only install the ATA drivers. This is an arbitrary (and stupid) decision made by MS, it means that if you install in RAID you can switch to AHCI or IDE mode after window installed with no problem (the drive just doesn't get used) while if you install in IDE mode windows will blue screen if you switch to AHCI or RAID; unless you manually install the drivers you need before making the switch in the mobo.