Is the stock apple 128 SSD 3G or 6G

I am trying to figure out whether the stock apple 128 gb ssd for MBP 15" is 3g or 6g. I am because I want to get the data doubler from owc, replacing my optical drive with another hd bay and that bay will only preform up to 3g, which is what OWC told me. Apple wouldn't tell me any more than they had on their site, and I searched a bit and couldnt find much. So if the ssd is 6g I would want it to run on the main bay which supports 6g, getting the most speed out of my drive and I would put a 7200rpm 750gb drive. But if it does 3g, I would put it on the second bay, so i can fit in a 12mm 5400 rpm 1tb drive. Or would the 750gb drive make more sense because of it's speed?


So to recap, whats the stock apple SSD speed, will it make a difference when in the 6G main bay or the 3G secondary bay.

And 7200RPM 750 GB drive vs 5400RPM 1TB drive.


Thanks!

so second thing

will the 7200 rpm make much of a difference over 5400 rpm? This disk will be mainly used for media, photos - videos - music. FCP, photoshop, itunes...