If it's just that then it's no issue, in fact it is integral to how CUDA works (I'm assuming loop step is constant over one run of a loop). You get the index of the current thread and you can use it - for example the CUDA prime check example is "check the first N integers for primes" -> start N threads and do a prime check algorithm on the thread index. The only problem happens if your loop #n+1 uses data calculated during the #n loop.