This is a can or worms and you probably need to consult with your AHJ to see what they allow. If you build the data center to NEC 645 specifications, you get some allowances. But most architects don't want all the hassles in a 645 area so they don't do it. Even if it is 645 compliant, they allow type DP cords on the equipment, but I have never seen a computer PDU cord with a type DP cord.
In our area, they allowed holes/notches/Vees in the floor tiles and a power box mounted under the tile right next to that cutout. Some would say this violates cords penetrating through floors and don't allow it. Next step after that is floor boxes which are quite expensive. These would be on FMC whips to a J box on the concrete floor. J boxes could be fed from a wireway but we just used conduits back to a big distribution box at the UPS/PDU. Repeated lifting of those tiles to pull cables or do other work (security inspections, smoke detector testing) tended to damage the FMC whips. LFMC is a little stronger, and even some of those split, but you need to be sure it has a plenum jacket which is harder to find.
I finally gave up and tended to have an overhead rack installed. Power receptacles would be under the top of the rack and a cable tray above it for network and other interfacing cables. Cords are fine above the floor, but not under. Don't know if the fire knows any difference in a data center that is unmanned most of the time.... Underfloor space could be used for interface cables, but most are not plenum (network cables are about the only easy ones to find as plenum). So your nice raised floor is mostly useless except for convenient HVAC distribution.
