Back in our launch review of fifteen Intel X99 motherboards for Haswell-E processors we weren't entirely sure about the purpose of ASUS' OC Socket, which contains more pins than the sockets other manufacturers incorporate in their boards. Haswell-E processors do indeed have more than 2011 contact points, a number of which are not actually used in the official socket. For the time being, Intel appears to be unable or unwilling to tell us why this is the case. Initially, ASUS was also unable to prove the claim that the additional pins can be used to deliver additional and more stable power.
During the tests for our upcoming Haswell-E OC workshop, we couldn't help but notice that the uncore, which includes functions such as the L3 cache and the memory controller, could be overclocked further on ASUS boards than on motherboards that are produced by manufacturers such as Gigabyte and MSI. This had a clear effect on memory performance. In the image below, you can see that memory performance is substantially improved when we increase the uncore frequency from 3 GHz to 4 GHz. The other settings are identical: a Core i7 5960X clocked at 4.5 GHz and DDR4 memory clocked at 3,000 MHz with identical timings. In the most favourable scenarios, the maximum speed of both the L3 cache and the memory is increased by some 30 percent.
It would appear that there is something special going on with ASUS' motherboards, and ASUS themselves claim that this is because of the OC socket. However, as far as we're concerned, this was not yet proven, as ASUS could also simply have employed some clever tricks in the BIOS. ASUS' competitors MSI and Gigabyte both claimed from the get-go that the OC Socket was primarily about marketing, and given that ASUS was unable to describe the exact function of their special socket, we were growing increasingly suspicious as well.
Proof at last
German overclocker Roman Hartung, better known under the alias Der8auer, recently delved into this subject and used an external power source to deliver power to two pins that aren't part of the regular socket, but are included in the OC Socket. After this modification, higher uncore overclocks were also possible on Gigabyte's boards, proving that the OC Socket is indeed beneficial. As a side note, the OC socket will only be useful to the most die hard overclockers out there, but that's precisely the crowd that ASUS is targeting with this feature.
German overclocker der8auer proved that providing a voltage from an external source to two non connected CPU pins provides the same capabilities of the ASUS boards on Gigabyte and other brands.
Intel remains unwilling to comment on the OC Socket and the potential consequences for your processors warranty. For "questions about products, implementations, and innovations by third parties" they refer us to the respective partners. Although ASUS claims that using the OC Socket will not void your warranty, Intel has not yet given a explicit statement on this. Rumours about processors that were killed by the OC Socket are often questionable. There are barely any concrete known cases, and for those that have been identified, there is no evidence the problems were indeed caused by the OC Socket. Moreover, similar reports can also be found for motherboards made by other manufacturers.
Regardless, this does prove that the OC Socket hasn't simply been made up by ASUS' marketing department, as the additional pins do indeed allow for higher overclocks. We can't help but wonder how the rest of this story will unfold. Apparently, ASUS has claimed exclusive rights on the special socket with Foxconn. That said, we do feel that the claims of ASUS patenting the OC Socket are rather implausible, as the processor socket has been invented by Intel, and patenting an adjustment to said socket likely isn't even possible. To be continued...
Left: the regular Socket 2011 v3, as used by ASRock, Gigabyte, and MSI
Right: ASUS' special OC Socket with additional pins