Mesa 6i25 and 7i76

Hi everyone,
I just received my 6i25 and 7i76, I have been reading and researching on configuring the cards and I'm wondering if Linuxcnc 2.5.3 will support the 6i25 in its native mode. The manual indicates it will run a bit faster and have a few additional features so I'd like to run it in that mode if possible. I've read a lot about running it in the 5i25 mode and will use that mode if necessary. I'm also wondering if the firmware I should use is the 7i76x2, I only have 1 7i76.

Thanks in advance for any help.

There is a slight advantage in running the 6I25 in native mode
(slightly faster I/O since the local PCI bus runs at 66 MHz instead of 33)
but I would stick with 5I25 mode just because its more supported.

The 7I76x2 configuration is the standard one for 7I76 configs
(unless you have a non-7I76 daughtercard on P2)

Thanks for the reply,
I will run it in the 5i25 mode then, the only reason I bought the 6i25 over the 5i25 is because of the PCIE bus.
I had a Sun Microsystems Sunfire x2100 server laying around and the 6i25 is the only card that will plug into the 1 expansion slot of the server. Turns out the x2100 seems to work well so it may be a inexpensive machine for Linuxcnc.
I see lots on ebay for less than $100.

Thanks again