2698 v3

I installed E5 2698 V3 for my server, I confirmed that I didn't have any energy saving settings turned on, and the cpu clock turbo in the BIOS is turned on. All-core turbo clock is 2.8Ghz, but single-core clock is only 2.5Ghz ? I don't know what's happened, should usually be 3.6Ghz or 3.3Ghz...