According to the Inquirer, AMD will start shipping it's upcoming Barcelona or Phenom processors into the channel next week, not a minute too late, as the lauch is slated for the 10th of September.
The bad news is that initial shipments will be of 1.9GHz parts and these are unlikely to be a real threat to Intel's Core 2 Duo/Core 2 Quad processors.
We'd expect the first batch of CPUs to reach system integrators first, before it becomes available from online retailers, but it might be worth waiting for the higher clocked models.
It seems like Intel doesn't have to worry as yet and can save it's upcoming CPUs until next year.
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