April 23rd marked the fourth anniversary for the chipmaker’s Opteron and the ground-breaking AMD64 architecture , and to mark the occasion AMD announced widespread availability and pricing for the latest range of AMD Opteron dual-core server processors .
 AMD also revealed updated performance numbers for its upcoming Quad-Core AMD Opteron™ processors, code-named ‘Barcelona.’ The new Barcelona projections show that AMD expects to have up to a 50 percent advantage in floating point performance and 20 percent in integer performance over the Intel’s “clovertown” quad-core processor at any given common clock frequency.AMD did not specify the clock speed of Barcelona. Intel’s Clovertown currently tops the chart at 2.66 GHz.
As for the performance of the new AMD Opteron Model 2222 and 8222 SE x86 dual-core server processors . AMD claims and I quote their website
“Under the newest SPECcpu2006 benchmarks, AMD Opteron™ processors continue to set the standard in x86 dual-core processor performance—besting our competitor by up to 15%. We credit that to our superior native dual-core design, with its Direct Connect Architecture, DDR2 memory, and industry-leading performance-per-watt. All with a clear migration path to native Quad-Core. It’s all proof positive that customer-centric innovation wins over hype.”
The AMD site also says
“Saying you’re the “World’s Best Processor” is one thing.
Actually being the “World’s Best Processor” is another.”

Considering their Dismal Q1 results , I would consider it a bold statement

More performance numbers
AMD Native Quad Core Tchnology

See the video where Randy Allen, Corporate Vice-President of AMD’s Server and Workstation Business talks about Barcelona