April 12 (Reuters) – Sberbank (SBER.MM), Russia's dominant lender and a leading technology company, is finding graphics cards the trickiest hardware item to replace in the absence of Western providers, CEO German Gref said on Wednesday. Sberbank needs the cards for its artificial intelligence services and super computers and Western sanctions over Moscow's actions in Ukraine have curbed Russia's access to some technology imports. "We depend first and foremost on technology called hardware," Gref told lawmakers in the Federation Council, Russia's upper house of parliament. "And probably the most critical position is graphics cards, microelectronics – video cards for high-performance…