Before revision:  However, for datacenter (in short, DC) computing workloads, such as Internet services or big data analytics, previous work reports that they have extremely low floating point operation intensity , and the average FLOPS efficiency  is only 0.1\% , while the average IPC is 1.3 (the theoretic IPC is 4 on the Intel Xeon E5600 platform). Furthermore, we reveal that the traditional FLOPS based Roofline performance model is not suitable for modern DC workloads , and gives misleading information for system optimization .
After revision:  However, for datacenter (in short, DC) computing workloads, such as Internet services or big data analytics, previous work reports that they have extremely low floating point operation intensity , and the average FLOPS efficiency is only 0.1\% . The FLOPS gap is 12X between the two systems equipped with Intel Xeon or Intel Atom processors, but the average user-perceived performance gap of the DC workloads is only 7.4X between them .