Advanced Micro Devices said its Shanghai processor is on track to ship in servers by the end of the year and sought to reassure customers that the problems that delayed its previous server chip, Barcelona, are a thing of the past.

AMD shipped the first quad-core Barcelona processors last September but halted sales soon after when a bug was found in the chip's cache memory. It didn't resume volume shipments for about six months, damaging AMD's reputation and costing it valuable market share to Intel.

Pat Patla, general manager of AMD's server and workstation group, said Tuesday that AMD has overhauled its testing process to avoid similar problems with Shanghai, another four-core processor being manufactured with a more advanced 45-nanometer process.

"We realized with Shanghai that we'd have to turn out a product early that had the stability and the health to make [server vendors] get engaged," he told reporters in San Francisco. "We realized their experience with Barcelona wasn't ideal."

AMD appointed a veteran engineer, Raghuram Tupuri, to close gaps in AMD's testing and validation processes. And it worked more closely with server vendors early on to ensure that the first samples of Shanghai, delivered around the end of February, were of higher quality, Patla said.

In a sign of how confidence in AMD had eroded, Patla said some server makers were still "a little hesitant" about working with the first Shanghai samples, and AMD had to ship them complete systems in order for them to test them.

He said he's now confident that the first Shanghai chip, a "mainstream" processor running at 75 watts, will be available in servers in the fourth quarter. Two other models will ship in the first quarter next year: a low-power, 55-watt version for blade servers, and a high-power, 105-watt version for large, "number-crunching" machines.

Shanghai will give a 35 percent performance boost over Barcelona on average -- meaning more for some applications and less for others -- and consume 35 percent less power, according to Patla. The improvements come partly from the move from a 65- to 45-nanometer manufacturing process and a larger 6M-byte Level 3 cache. In addition, the Shanghai cores will run at a higher clockspeed than those of Barcelona, but those details, along with pricing, won't be announced until the chip is closer to launch.

The IDG News Service is a Network World affiliate.