If you have one, you must have the other. And so it is that after today's latest rumour about the PlayStation 4.5 - allegedly codenamed "NEO" - today sees fresh reports that Microsoft is testing "a variety of prototype Xbox devices".

The new information comes from The Verge, who report that Xbox sources have told the tech website that at least some of the prototypes have been "tested with upgraded components you'd use to improve the performance of a PC gaming rig."

Of course, prototypes are a constant concern for a console manufacturer, and it's by no means guaranteed that any of these will hit the market. Couple that with the fact that Head of Xbox, Phil Spencer recently said that he wasn't a big fan of the idea of a mid-generation console upgrade, and this could seem unlikely.

However, recent filings with the FCC sparked speculation as to work beginning on a brand new Xbox and a possible "slim" model, while Phil Spencer said last month that he's interested in hardware improvements that allow for "backward and forward compatibility".

We have contacted Microsoft for comment.

Joe Skrebels is IGN's UK News Editor and he waits with bated breath for the announcement of the Commodore 66 or the GameSphere or something. Follow him on Twitter.