The giant chip maker Intel, facing antitrust challenges around the world, announced on Thursday that it would pay $1.25 billion to settle its long-running disputes with its smaller rival, Advanced Micro Devices.

The settlement, covering both antitrust and patent claims, ends the computer industry’s most bitter legal war.

But the truce may not be enough to turn around the fortunes of A.M.D, which has struggled to come up with chips that give it any significant technological or performance edge over Intel, which supplies about 80 percent of the microprocessors that sit at the heart of personal computers.

At least in the short term, the settlement also does not end Intel’s antitrust problems. Governments in Europe, the United States and Asia have accused the company of systematically using large rebates and co-marketing arrangements to persuade computer makers to use its chips instead of those made by A.M.D.