If this is as good as it gets, there's obviously a significant underlying issue, as the memory itself should provide much higher bandwidth.

And the Qorlq line's focus on network capability, with it deemphasis of serdes connectivity is problematic.
If you were to use the e5500 or e6500 cores in a CPU designed with end user computing devices, you'd probably want to rework some of this to provide better support for other devices.

Still, from the recent benches I have seen Spectre660 post, the overall performance of the X5000 still measures up fairly well.