Phoronix published a review on the Scientific Linux 6.6 vs. Scientific Linux 7.0 Benchmarks
A quote from the article:
Scientific Linux 6.6 vs. Scientific Linux 7.0, which of these Red Hat Enterprise Linux derived distributions are faster? Here's some benchmark results from a ten-core Xeon systemScientific Linux 6.6 vs. Scientific Linux 7.0 Benchmarks @ Phoronix