My searches usually error out after 7 days or so of running at 16Mkeys/sec (~12 quadrillion tries).
If you just restart it, nothing is lost. It just makes a clean random start at another point than where you started before.
Are there settings that reduce the amount of GPU that is being used
You can reduce the number of threads it uses:
./oclvanitygen -t 10 1testt
Difficulty: 15318045009
[868.99 Kkey/s][total 34037760][Prob 0.2%][50% in 3.4h]
I highly doubt this will help though: it slows down my system just as much as when I run oclvanitygen at full speed. Unless your "out of resources" means out of memory, in that case less threads could help.
Alternative: set it to save results to a file, and set it to restart after it crashes.