osmo-bts-trx fails frequently on osmo-gsm-tester

We're still having massive stability problems with osmo-bts-trx on the osmo-gsm-tester. I have run a tcpdump on the ntp port for the past days, and nothing is doing ntp besides the actual ntp service. Today I started ntp while an osmo-bts-trx run was active and what do you know, the osmo-bts-trx process exits immediately. I think this is bad, osmo-bts-trx shouldn't use wall clock time for precise timing needs. Besides that, I have no idea what could cause the clock skews, except maybe that the CPU or the USB are not fast enough?? I'm wondering, is there still such a thing as a separate linux realtime kernel? We will soon take to productive use another main unit which will be a cleanly installed OS. If we see the same problems on that system and can't find a software fix, we may need to reconsider the tester for osmo-bts-trx... ~N