A few weeks ago Microsoft also anounced overclocking of ESRAM. In X1 DD3 is supplemented with memory embedded into GPU chip - ESRAM. Now it is possible to achieve 68GB/s from DDR3 and 192GB/s from ESRAM for a total theoretical 260GB/s in X1.

http://www.eurogamer.net/articles/digitalfoundry-xbox-one-memory-better-in-production-hardware
"The 32MB of "embedded static RAM" within the Xbox One processor aims to make up the difference, and was previously thought to sustain a peak theoretical throughput of 102GB/s - useful, but still some way behind the 176GB/s found in PlayStation 4's RAM set-up. Now that close-to-final silicon is available, Microsoft has revised its own figures upwards significantly, telling developers that 192GB/s is now theoretically possible."


Both memory types work in tandem and newest DirectX 11.2 (only for Windows 8.1 and Xbox 1) allows for using that 32MB with many GB models with Sparse Texture and other extra new functions:

http://www.geeks3d.com/20130627/directx-11-2-revealed-with-windows-8-1-preview/

This is called Tiled Resources:

http://www.youtube.com/watch?v=EswYdzsHKMc
http://media.ch9.ms/ch9/f740/c048966d-93f7-42b6-97a4-69dae303f740/3-062.webm

Also worth noting in DX 11.2

GPU overlay support and Frame buffer scaling - X1 have them for dynamic *hardware* scalling like RAGE and WipeoutHD did in software. Stable 60fps or 30fps with no tear (and no need for triple buffering - less lag) all the time.

http://www.vgleaks.com/durango-display-planes/

http://www.eurogamer.net/articles/digitalfoundry-rage-face-off
http://www.eurogamer.net/articles/wipeout-hds-1080p-sleight-of-hand

Only in pure core numbers crunching PS4 will have any advantage - and in practice those will give PS4 maybe a few fps more (or more resolution in busy scenes) IF the fact that DX11.2 will be a LOT easier to optimise than PSGL (Sonys OpenGL) won't make it moot in 99% of games.

And with dynamic scalling you won't be even able to see it.