Update: It's true. The new additions include a rebuilt and optimized graphics driver and the GPU’s clock speed changing from “800mhz to 853mhz.”
Original: It's being reported this morning that Xbox Live director of programming Larry Hryb and Microsoft's Marc Whitten will release a podcast detailing changes to the Xbox One's GPU.
The Xbox One will have a custom AMD GPU which is said to be similar to the Radeon HD 7790. What this means in real terms is support for 2 GB of DDR5 RAM, the ability to support 4K resolutions and has a graphics clock of 800 Mhz.
Well, according to a Gamespot Japan [via] report the hardware has now been slightly improved, with the GPU speed being upped by 53 MHz since E3.
Microsoft is apparently looking to upgrade the system as much as possible before launch, which is obviously good news all round.