I've just taken the plunge, and obtained a 750Ti: at the moment, it's in host 170387.

It may be the luck of the draw, but the first two tasks allocated have both been cuda60 (I made sure it was allowed to fetch short queue only before I attached).

The correct way to ensure this in the plan_class specification would be to add a restriction based on Compute Capability to cuda42 and cuda55: don't allocate if Compute Capability < (strictly) 5.0

Some people are saying that their hosts are trying to run earlier apps on their 750Tis. May I ask if these are in hosts with multiple GPUs - a 750(Ti) and an earlier model as well? BOINC is bad at handling this: tasks are allocated to the computer, not specifically to the card, so if you have a CC 2 or CC 3 card in the machine, it passes the test and can get cuda42 or cuda55 work - which can end up being run on the Maxwell. I'll need to think if there's a way round that.

Small side comment: it took ages to get the first task running on the new machine, while the (huge) cufft32_55 DLL downloaded. That's not needed by this app (nor is the v4.2 cufft DLL), and won't be used on this host by this project. A little optimisation of your application version generator would be welcome.