Intel's unlocked Pentium G3258 CPU—or the Anniversary Edition—has been a constant presence in our System Guides for over a year now. For under a hundred bucks, that two-core, two-thread processor can reach stratospheric clock speeds with a little tweaking. Intel didn't announce a successor to the G3258 when Skylake rolled around, and the dual-core wonder has had problems with some games. Budget builders may need a new hero, and Anandtech says that hero will be motherboard manufacturers. Supermicro, ASRock, and Asus seem to have found ways to enable base-clock overclocking on locked Skylake CPUs.
As Scott noted in our review of the Core i7-6700K, the base clock (BCLK) is no longer tethered to the chip's PCIe and DMI clocks. That means overclocking a CPU using the BCLK won't throw other parts of the system out of whack. Despite that change, Anandtech reports it's had no success achieving a significant overclock with a Core i5-6500—results that mirror my own attempts with a Core i3-6100.
Still, a pair of extreme overclockers hit 5GHz recently using BCLK overclocking with locked Skylake Core i3 processors and liquid nitrogen. Anandtech contacted Supermicro, which supplied the motherboard for extreme overclocker Dhenzjhen's 5GHz Core i3-6300 run. Apparently, the same BCLK-unlocking voodoo used in that experiment will make its way to Supermicro motherboards in the near future.
Shortly after that, ASRock contacted Anandtech and shared CPU-Z screenshots of a locked Core i5-6600 running at 4.5GHz on the company's Z170 Extreme7+ motherboard. Those results only required an experimental BIOS. ASRock said it's still putting that BIOS through internal validation, but it could be released to consumers as early as next week.
Asus also appears to have figured out the trick to an unlocked BCLK. An overclocker going by the name elmor took a Core i3-6300 to a dizzying 5.8GHz on an Asus Maximus VIII Gene. Asus didn't provide any more details of that achievement to Anandtech, though, so an Asus BIOS update that would enable BCLK tuning on the company's mobos seems like less of a sure thing.
Update 12/11/2015 12:11 PM: Julio Franco (not the former baseball player) from TechSpot emailed to let us know that the site got its hands on a beta BIOS for ASRock’s Z170 Gaming K6+. TechSpot took a Core i3-6100 to 4.7GHz with this experimental firmware. ASRock will reportedly release BIOS updates for all of its Z170-based motherboards to enable locked-CPU overclocking "very soon."