阿里云的CPUXeon为什么比i7-4790K慢这么多？

阿里的CPU的配置是Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz ， 我的PC配置是 Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
两个机器都运行CentOS。 这两个CPU的性能应该相差不远的， 但是同样的程序，阿里云上运行时间是i7运行时间的3倍。


我做了一个Sysbench 测试。 sysbench --test=cpu --cpu-max-prime=20000 run


结果是


Aliyun

Intel(R) Xeon(R) CPU E5-2630 0 @ 2.30GHz


Test execution summary:
    total time:                          37.9879s
    total number of events:              10000
    total time taken by event execution: 37.9846
    per-request statistics:
         min:                                  3.70ms
         avg:                                  3.80ms
         max:                                  7.30ms
         approx.  95 percentile:               4.02ms


Threads fairness:
    events (avg/stddev):           10000.0000/0.00
    execution time (avg/stddev):   37.9846/0.00




------------------------------------------------------------
I7    
Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz


General statistics:
    total time:                          20.5073s
    total number of events:              10000
    total time taken by event execution: 20.5056s
    response time:
         min:                                  2.05ms
         avg:                                  2.05ms
         max:                                  3.35ms
         approx.  95 percentile:               2.05ms


Threads fairness:
    events (avg/stddev):           10000.0000/0.00
    execution time (avg/stddev):   20.5056/0.00
阿里云的CPU需要37秒完成I7 20秒就能完成的测试。


这是怎么回事？