The Need to Overclock…Your CPU?
I've been using 3DMark Fire Strike as a synthetic benchmark since it came out in 2013. Its "basic" run (non-Ultra and non-Extreme) is pretty taxing on GPUs in its two graphics tests. The other two tests tend to be CPU-bound.
So here's the news: two Titan X (Pascal) cards in SLI are actually CPU-bound in the first graphics test of Fire Strike, though not in the second. And that’s with a Core i7-6700K boosting to 4.2 GHz. Forget about using Unigine Valley or other older tests to saturate the Titan Xes. GPU utilization sits at around 50% in those; the bottleneck is clearly our host processor.
I managed to get the two cards in SLI stable at +190 MHz core and +160 MHz memory, which represents about a +10% overclock. As you no doubt know, clock rates in SLI are synchronized, so your headroom is limited to the less-scalable GPU.
MORE: Best CPUs
MORE: Intel & AMD Processor Hierarchy
MORE: All CPU Content