There has been a fair bit of action at the top of the GPUPI 1B benchmark rankings in the last week or so, almost all of it revolving around Nvidia Titan X Pascal cards. Almost exactly a week ago US legend k|ngp|n submitted a score 2sec 349ms using quad SLI’d Titan X Pascal cards with all four GPUs pushed to 2,550MHz (+79.96%) on LN2 – a score widely heralded as utterly exceptional, and possibly even insurmountable. Today we can confirm that this score has now been blown away by a new World Record GPUPI 1B run from dhenzjhen of just 1sec 787ms.
The new World Record score for GPUPI 1B was in fact made using a server rig of almost inexplicable girth. Prepare yourself for a nasty case of rig envy! In short, its seven Titan cards are joined in an unholy alliance with a pair of 10-core/20-thread Broadwell-EP Intel Xeon chips. After just a quick calculation, I’m pretty sure that the CPUs and GPUs alone in this rig would cost in the region of 14K USD. The electricity bill will be no sweat heart either, seeing as the combined TDP of all that high-end silicon is over 2,000 Watts.
Dhenzjhen took a pair of Intel Xeon E5 2689 v4 'Broadwell-EP’ configured at stock settings and setup a rack mounted rig containing no less than ten Nvidia Titan X Pascal cards. The GPUs were then pushed to 2,800MHz (+44.67%) with memory tuned to 1,300MHz. The result is a GPUPI run of 1sec 787ms, pretty far ahead of k|ngp|n’s 2sec 349ms.
What’s is interesting to note is that despite having seven cards installed on the rig, Dhenzjhen ended up disabling three of them. It turns out that Nvidia Titan XP cards have trouble with negative scaling beyond seven GPUs.