Hi Aaron,
I'm not clear what does it mean "will Carizo OpenCL perf be greater than 7700?". One way, you may simply figure out by comparing both specs (say number of CUs, total number of cores, frequency, GFLOPs, Memory etc.). However, application scope of APU and dGPU may not be same. With Carizo APU, you'll get HSA and OpenCL2.0 (with higher GCN version than HD 7700) support, so you can exploit certain OpenCL2.0 features which may impact the performance significantly over the old HD 7700 dGPU card. So it depends on your usage. IMHO, if you don't want to use any benefits of APU or new features of OpenCL, comparing both the spec. is more intuitive. As Carizo is still not available, it would be difficult to comment about the actual performance differences. But, I can say performance of the APU are getting better day by day and it'll continue in future.
Regards,