All mac pros support SATA II only, and not SATA III unless you have a 6GB card from Newertech or some other company or 3rd party. You would need to see if the SSD drive you purchased has jumpers on it to set it from SATA III to SATA II. Most drives are still backwards compatible. Take a look at your drive and see if there are any jumpers on it. Then try it again.
But SATA III outside the box is not going to work in any mac pro at all unless you have a PCIe SATA III card.
Why do you think it won't? they are totally backward.
But you also dont think we need to know the make, model, and if there is firmware update.
OWC has just posted their own. One thing about buying theirs, they support us, they buy and charge for prremium parts.
It isn't going to get 500MB/sec but an SATA II is going to work and improve your system. You don't need a controller, and if you want to boot from the SSD you are limited as most are not OS X bootable.
Google. Not familiar at ALL with that make.
And the vendor. See if they have RMA and firmware etc.
Intel just posted firmware for their 510, and I'd avoid OCZ 128GB.
With hard drives I always use vendor and Windows to recertify all the sectors.
My memory is that when this happened to others it was the unit itself and a replacement should work.
SSDs are small and never seen any documentation etc of needing or having jumpers. Plus even 7.2K 6G hard drives like WD Black etc work just fine as is in Mac Pro.
But if you want or need 6G, skip any 1x controller and look for one that is 4x and can handle more than one device.
Disk utility doesn't see it either. Even tried it on a Win 7 machine and it didn't detect it either.
Then it's not there, and cannot be initialized, repaired, or used in your Mac.
It is either a dud or does not work in your Mac. Return it for a refund, or try a brand or a Vendor that is more Mac-friendly and will tell you, up front "this works in your Mac."