Which is faster? Internal or external RAID 0 on MacPro?

I'm trying to squeeze the last bits of speed out of my ancient MPro.
I'm currently using an external 2tb esata drive for my media.
thanks in advance

In theory using an Apple RAID card for an internal RAID will be fater than a software RAID internally. Hardware RAID is going to be pretty much the same internal or external. Personally I prefer hardware RAID.

Does anyone have any experience with this OWC Mercury Rack?
eshop.macsales.com/item/Other%20World%20Computing/RPM3F8Q02.0T/
Looks promising.

I just purchased this one eshop.macsales.com/item/OWC/MEQX2T16.0S/
a few months ago configured as RAID 5 and also an internal Sata III 6 GBPS card for my Mac Pro. This is basically what you are looking at, only in a larger upright enclosure as opposed to the 1RU unit.

Bottom line for me is that it is outstanding, and extremely fast. I have 12 useable TB of storage as the RAID 5 configuration eats up one of the four 4TB drives.

That particular OWC mercury rack will not be any faster that four internal drives on a Software RAID0 setup.

Thanks.
Now here's the $64,000 question...
How about a single SSD drive? Like this?
www.bhphotovideo.com/c/product/897033-RE..._5_inch_SSD_840.html

That drive would be faster alone if you had a PCIe card (ie. Velocity Solo X2) with a 6Gb to connect the SSD drive. It would be cheaper to just buy two SSD that were only Sata ii speed (300MB/sec) with half the space and RAID0 them internally.

Most likely the next mac pro will have Sata iii. If apple was looking ahead to keep the mac pro up to date for a while they might make the drive ports sata iv. The latest SSD drives totally max out the Sata iii spec.

I'd like to see an internal T'bolt and SSD drive options. You'd not have any faster drives than that.

But for maximum storage space with maximum speed, internal T'bolt using SATA 3 would be nice.