U.S. researchers are bracing for the prospect that China will once again have the world's fastest computer─and could hang on to the speed crown for some time.

        China's National University of Defense Technology last week informed visiting scientists about a massive machine in Changsha whose initial test results appear likely to top the next ranking of the 500 largest supercomputers, scheduled for release later this month.
        中國的國防科技大學上周告知來訪的科學家們，中國一台巨型電腦的初次測試結果顯示，它有可能在定於本月晚些時候公佈的最新一期全球超級電腦500強排行榜上位列第一。
        Such systems, used heavily by government agencies for purposes such as weapons design and intelligence-gathering, have long been seen a symbol of national competitiveness─and the focus of recent leapfrogging moves by the U.S., China and Japan.
        巨型電腦主要被政府機構出於武器設計和情報收集等目的而使用，它們一向被視為國家競爭力的象徵，世界運算速度最快電腦的寶座近年來一直被美國、中國和日本這三個國家交替佔據。

        A supercomputer in China unveiled in 2010 briefly topped the global speed ranking. But U.S. research institutions recently have fielded the fastest hardware, led by a machine called Titan at Oak Ridge National Laboratory.
        The new Chinese system─called the Tianhe-2, or Milkyway-2─uses two different kinds of computer chips from Intel Corp. INTC -2.60% as well as some homegrown circuitry, according to Jack Dongarra, a U.S. supercomputer expert who saw the system last week. He published details about the machine that were reported earlier by the publication HPCwire.
        'It's a real system,' said Mr. Dongarra in an interview Wednesday. 'It seems to be ready for production.'
        Mr. Dongarra, a professor at the University of Tennessee who is also on the Oak Ridge research staff, said Chinese officials put the system's theoretical peak performance at 54.9 quadrillion operations per second─or petaflops, in industry parlance. It reached 30.65 petaflops in a standard test known as Linpack, he said, compared with 17.59 petaflops for the Oak Ridge system.

        The U.S. has previously responded to such challenges, including a system from Japan that temporarily held the top speed ranking. But the next U.S. supercomputer that could challenge the Tianhe-2 isn't expected until 2015, said Horst Simon, another supercomputer expert who is deputy director at Lawrence Berkeley National Laboratory.
        美國之前曾經回應過此類挑戰，包括運算速度曾經排名第一的來自日本的系統。但是另一名超級電腦專家 Simon 說，美國能夠挑戰天河2號的下一台超級電腦預計到2015年才會出現。 Simon 是 Lawrence Berkeley 國家實驗室的副主任。
        'If anybody believes that the Chinese are just in there for a stunt, this machine has proven them wrong,' Mr. Simon said.
        He argued that the U.S. government has invested sporadically in supercomputers lately, while Chinese agencies have spent steadily. 'In some areas where there has been a tradition of U.S. leadership, the Chinese are out there to really be in the race and win,' Mr. Simon said.

        No official price has been released for the Tianhe-2 system, which was constructed with help from the Chinese company Inspur. But some U.S. researchers put the likely cost at $200 million to $300 million.
        Tianhe-2 is a big endorsement for a new Intel product line. The Silicon Valley company's standard microprocessors have been used in supercomputers since the 1990s. But some big machines lately have been enhanced with chips called GPUs, or graphics processing units, from companies such as Nvidia Corp.
        天河2號是對英特爾一個新產品系列的巨大認可。自從上世紀90年代以來，這家矽谷公司的標準微處理器就一直被用於超級電腦中。但是一些大型電腦近來使用了來自 Nvidia 等公司的“圖形處理單元”(GPU)晶片，並因此提升性能 。
        Intel has responded with the Xeon Phi, a specialized chip with as many as 61 calculating engines. The new Chinese system has 48,000 of those chips, as well as 32,000 conventional Xeon chips based on a forthcoming design not yet generally available, according to Mr. Dongarra's report.
        英特爾的回應是推出了Xeon Phi，這是一種擁有多達61個計算引擎的專業晶片。根據 Dongarra 的報告，中國新的系統擁有4.8萬個Xeon Phi晶片，以及3.2萬個傳統的Xeon晶片，這些晶片基於一種即將推出且尚未普及的設計。

        In addition, the system has about 4,000 chips developed in China that are based on a standard design called Sparc. Mr. Dongarra said Chinese officials appear determined to reduce their dependence on U.S. components.
        除此之外，這一系統擁有大約4,000個在中國開發的晶片，這些晶片基於一種叫做Sparc的標準設計。 Dongarra 說，中國官員似乎下定決心減少對美國零部件的依賴。

        He doesn't discount the possibility that government agencies in Japan will field a system to rival the Tianhe-2, but he regards the Chinese system as particularly impressive. 'In some sense, it's a wake-up call to the U.S.,' Mr. Dongarra said.