we've accelerated 4 out of 5 hashing algos for HVC, but the last one (Groestl) is causing us a bit of trouble.
Our first port is actually slower than the CPU - at least on my system.
Running Groestl on CPU and the rest on GPU I am getting an 800% performance boost vs. running the CPU alone.
Multiple CPU threads can even share a GPU

Note that overall HVC is *not* CPU-only. They really need to change their advertising, and change it quickly. Whatever they did to SHA256 to turn it into a "GPU and ASIC resistant" HEFTY1 algorithm - it didn't work as they intended.
Christian
What hash rates are you getting on your hardware? Just want to compare... something.