I don't get why there's such a big power difference.

[freedquaker]

Jizz_Beard_thePirate said:

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On top of that, ps4 is all gddr5 vs xbox one is ddr3 + small amount of edram... Gddr5 is faster than ddr3 but eDRAM is way faster than both however, the x1 only has a small amount of eDRAM to work with plus the developers have to use it properly to make it effective which is why the ps4 is overall faster... (I might be a little off somewhere though)
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Where did you get the idea that Esram is way faster than GDDR5?  Esram has a 102 GB Bandwidth one way, although it can be used to write and read simultaneously, which implies a Maximum of 204 GB Bandwidth. Well, this is VERY theoretical because you will not have read and write simultaneously 100% of the time, and as Anandtech suggested, the expected theoretical maximum is around 170 GB/s

GDDR5 has a 176 GB/s Bandwidth, and with some overhead this nets to around 172 GB. Well, for all practical purposes Esram and GDDR5 have similar speed. So, no Esram is NOT faster than GDDR5 at all. But it has one advantage; very low latency. Without that, 32 MB of ESRAM would be completely meaningless, as it would be too small. So "loading and unloading data" is very quick.

This is crucial for XB1 because it's trying to compensate the sluggish DDR3, since it will load and unload data again & again (with its tiny size), especially using compression technics.  The latency on GDDR5, on the other hand, is not that important, because once you load the data, and you can fit it all, you don't have to unload it until it's delivered.