When I was shopping for one a few months ago, it wasn't explicitly mentioned it X520 specs but mentioned in Mellanox specs. I know that in the theory it suppos

When I was shopping for one a few months ago, it wasn't explicitly mentioned it X520 specs but mentioned in Mellanox specs. I know that in the theory it supposed to downgrade itself, but implementations may vary depends on fantasy of designers. At the end, I just got motherboard with few 10GbE and SPF+ on it.