It seems they will only complete if you never need to suspend BOINC or the project for at least some days or possibly more than a week. The moment you have to suspend the project, or suspend use of processor/GPU for running BOINC project tasks, or reboot the machine (such as installing a Windows update or installing/uninstalling an application, all the work for that RNA task is discarded. So on my machine where it is likely that such a suspension is required at least twice a week, the result is that none of those cmsearch XXL tasks will ever complete. Thanks to the pointer on where I can disable cmsearch XXL WUs from running - I've now done that.
This is a pity. The applications from other BOINC projects save their state on suspension so that they can resume without discarding all the work achieved on them to-date. This is the most user friendly design to which BOINC apps should aspire. After all, it's my machine and when I need to run my own resource intensive apps, I should be able to suspend BOINC so that resources are relinquished so that I can the applications.
Yes, it is correct and known (FAQ) that RNA World supports checkpointing only for 32-bit Linux machines which have memory randomization disabled in the kernel. However, you should activate the switch "keep application in memory" in the general BOINC settings - and this not only for the RNA World project - to avoid loss of data when pausing the task. Sending Windows to hibernation mode should then NOT result in loss of the computational results and should consequently allow you to turn your machine off for a while (in hibernation mode, only!).
As described earlier on many occasions in diverse discussion fora, we are not keen on implementing checkpointing at the science application level for multiple reasons. Among these is the fact that the current application would have to be re-written. And this application is not developed by our team. The second most important argument is that unlike other distributed computing projects, our project already consists of multiple applications and will be massively extended in the future. We therefore require a BOINC-integrated, universal checkpointing mechanism as we cannot re-write all the applications each time a new version is released. Such a universal approach would also be beneficial to all the other projects and, to my point of view, is therefore of utmost universal importance. Unfortunately, there seems to be zero efforts from the BOINC developers to take this request serious. As a consequence, I cannot exclude that RNA World might one day migrate to a different, more advanced DC infrastructure that satisfies our needs in a more timely fashion.