I'm sorry, but the data you've shown is exactly what's supposed to happen.
You're completely random-accessing and looping through 253MB of data, which obviously does not fit in the cache, and VTune is telling you that you're DRAM bound. This is exactly what will happen if the first iteration indexes the float and float; and the next iteration indexes the float and the float. The cache is effectively useless, and all the bottlenecks will be in the DRAM.
What do you expect it to tell you?