South Korean memory chip maker SK Hynix Inc said on Wednesday its October-December operating profit more than doubled to a quarterly record high, boosted by healthy demand from servers and new smartphones launched by Apple Inc. SK Hynix, the world's second largest maker of DRAM chips used in personal computers and smartphones, said its DRAM shipments rose 18 percent from the previous quarter while the average selling price fell by 3 percent. Memory chip makers have been booking higher profits in recent quarters thanks to better-than-expected demand for personal computers and data servers as well as careful capacity management across the industry.