Can a Sata II SSD array be faster than Sata II on a Sata III motherboard?

What I mean is, if I take two SSDs that can obtain speeds like 250MB/s and make a RAID array will it be limited to 300MB/s because they are Sata II, even though the motherboard used has a Sata III bus?

 

A SATA II drive on a SATA III bus won't show any kind of speed improvements. The bus will adapt to whatever standard the drive is.

EDIT: I'm not quite sure I get the question, and I've read it like 3 times.

 

No, you'll use two SATA/300 channels so you'll be able to double your sequential speeds to 500MB/s. Though you probably won't notice a difference since you lose TRIM and sequential speeds aren't that important (except for lots of large file transfers).

 

I'm not asking about an invidual drive.
I'm not sure how to be more clear, so I will ask it differently.

If I get two separate SSDs that are Sata II and setup an RAID array on a Sata III compatible motherboard, would them together on the same array still be limited by the Sata II speed, or would the Sata III bus be able to add the speeds of both as Sata II x 2 = Sata III bus speed?

Edit: While I was typing the guy above got it right, thanks

 

You won't notice a difference between SATA/300 and SATA/600 for RAID0 drives that aren't even capped under SATA/300.

 

Depending on the specific implementation of the SATA III chipset, you may even find that it will be slower compared to running it on a SATA II chipset.

 

Intel RAID supports TRIM through specific firmware. All other manufacturers are a no. Highpoint is supposed to be releasing a RAID card that supports TRIM soon.

 

Which Intel firmware supports TRIM?

 

Intel Chipset Driver Brings TRIM Support to RAID Setups | Hardware Canucks

 

First thing I saw on that link: