Original Link: http://www.anandtech.com/show/7528/the-xbox-one-
mini-review-hardware-analysis             The UI and
Multitasking      The Controller       Performance - An Update
The Chipworks PS4 teardown last week told us a lot about what’s
happened between the Xbox One and PlayStation 4 in terms of
hardware. It turns out that Microsoft’s silicon budget was
actually a little more than Sony’s, at least for the main APU.
The Xbox One APU is a 363mm^2 die, compared to 348mm^2 for the
PS4’s APU. Both use a similar 8-core Jaguar CPU (2 x quad-core
islands), but they feature different implementations of AMD’s
Graphics Core Next GPUs. Microsoft elected to implement 12
compute units, two geometry engines and 16 ROPs, while Sony went
for 18 CUs, two geometry engines and 32 ROPs. How did Sony
manage to fit in more compute and ROP partitions into a smaller
die area? By not including any eSRAM on-die.  While both APUs
implement a 256-bit wide memory interface, Sony chose to use
GDDR5 memory running at a 5.5GHz data ra