AMD's linux problem is multiple. Their screwing around with side stepping cpu architectures has killed them. Today I can build a dual socketed intel server that will beat out AMD's quad socket offerings, both on cpu throughput and power use. It's just not pretty.
The only thing it seems they have left today is the good gpu performance on their brazos and llano laptop offerings. Everything else seems to be a joke, the result being intel jacking up their prices.