P106-100s are 6GB, are those going to be viable on mainnet?

The P106-100 will not be viable to use with the basic Grin miner but we are working on some memory optimisations for our miner that will make it possible. We won’t have this ready for launch but shortly after. It’s our main priority after launch.

What is the interface tor managing multiple miners? Is there a central dashboard?

The software will consist of two parts. A main dashboard which will be web based and then remote agents that are installed on each rig. The remote agents will be platform agnostic.

How many graphs solved per second can your grin miner do on different GPUs?

We are still doing testing on the miner so don't have all of the figures just now. We did a benchmark test 2 days ago run on CUDA master - looks like it's faster compared to grin-miner, 3% CPU usage on single 1080Ti and i7 but it's a bit early to say for certain. We will publish a table comparing both miners on Nvidia/AMD rigs shortly.