Advanced Micro Devices Inc. believes that a greater percentage of its graphics revenue came from cryptocurrency mining in the first quarter. In a conference call after the chip maker released first-quarter earnings, Chief Financial Officer Devinder Kumar revealed that blockchain-related revenue was about 10% of AMD revenue in the quarter. Previously, AMD had insisted that crypto-mining revenue was mid-single-digits percentage of its revenue. Kumar did say that AMD expected a "modest decline" in blockchain-related revenue in the current quarter, and said that has been factored into the company's second-quarter guidance, which beat expectations. AMD stock got an extra boost during Wednesday's call, with an 8% gain jumping to more than 11%.