Are you sure you have an R7 270 ? I cannot find that product listed anywhere - although I do find a R9 270 series product.
Who is the manufacturer of the product ? Do you have a website link to the product specs ?
The component I have in question was named in the Device Manager as AMD Radeon R7 270 but has changed to AMD Radeon R7 200 Series. The Manufacturer is box standard AMD, nothing like Sapphire or GigaByte. I've been trying to find the product specs myself but all I've found so far are links to the Catalyst Driver, not the actual graphics card.
If you want to look into this in a bit more detail you can look at the Hardware ID's obtained from my Device Manager: