Is this normal?

[CHR15x94]

Don't worry about it. I get that too. The core that is hitting ~100% is emulating the Wii/GC's PPC processor, which uses a lot of CPU power. The other core is the one emulating the Wii/GC's GPU which isn't as high a MHz as the PPC, so doesn't use as much power. (The PPC is clocked at about 485[GC]/729[Wii]MHz, and the GPU 192[GC]/243[Wii]MHz)

Hope that answers your question!

- CHR15x94