Stop With The Mobo Auto-overclocking Shenanigans

RECENTLY, AMD X570 MOTHERBOARD makers came under scrutiny for potentially running the latest Zen 2 CPUs out of spec. This is nothing new, though the methods behind the Zen 2 “cheats” are slightly different. There are various opinions, which distill down to two basic philosophies.

One is that enthusiasts want their PCs to run as fast as possible, and any tuning that a motherboard manufacturer might do in a BIOS is fair game. The other take is that any auto-overclocking or beyondspec tuning should be disclosed in the settings, and by default a board should run at stock.

With AMD’s AM4 X570 boards—and let’s be clear, this isn’t the first time this has happened, not even for socket AM4—the problem is that some motherboards are reporting an incorrect current (amps) value to the CPU. The CPU uses this value to determine voltage, power, and clock speed, seeking to stay within the specified limits. If the motherboard “lies” and says the current is lower, then the CPU will be able to exceed the normal power limits and potentially run faster.

This technically voids your AMD CPU warranty, just like Precision Boost Overdrive. Whether or not these hacks could cause a CPU to fail is more difficult to nail down. Long term, Zen 2 CPUs built on TSMC’s 7nm lithography might be more at risk than 12nm and 14nm chips, but it would still likely take years for most CPUs to fail.

There are some other consequences, however. The biggest is CPU power use, which directly translates into heat. If you’re running a fourcore or six-core 3rd-gen Ryzen, there’s probably nothing to worry about—even eight-core Ryzen 7 3700Xs should be okay. Instead of 65W, your CPU could potentially use as much as 95W, which is well within the limits of what the silicon can handle. No big deal. But with a 105W 3800X, 3900X, or 3950X, power use could be substantially higher. We’re talking 160W during “stock” operation, and at least one vendor (ASRock) has some boards that can hit as much as 210W of power draw—all on the CPU.

With proper cooling, it’s still unlikely to cause any serious issues in the near term. However, some users have noticed substantially higher temperatures on high-end 3rd-gen Ryzen processors, as the Wraith Prism potentially struggles to dissipate 150W of power. Other CPU protections kick in, and “throttling” may occur to keep the CPU below 90 C or whatever, except in this case the throttling is probably just moving the CPU back toward running at official speeds and power. Still, 90 C and higher temperatures are a serious concern, so a user might end up buying a more expensive cooling solution just to keep things running properly—which could mean spending $100 or more to cool a CPU that’s running hot because of hidden automatic overclocking.

I’ve seen test results where on some boards the “stock” performance is higher than what can be achieved with PBO, meaning the motherboard vendors are overclocking via the amperage cheat more than you can get with PBO. Interestingly, enabling PBO appears to disable the erroneous amperage reporting, so vendors were smart enough to know that double-overclocking is a bad idea.

But let me get back to the bigger picture. While AMD boards are the most recent example, they’re by no means alone. Intel doesn’t even report official all-core turbo clocks any longer, basically letting motherboard vendors run free. There are Z490 boards for the new Comet Lake CPUs that will run the Core i9-10900K at 250W, indefinitely—assuming that your cooling can keep up. Perhaps even worse, I remember testing the first Skylake-X CPUs a few years back, and seeing system power draw during a Cinebench run eclipse 450W with a Core i9-7900X. Even liquid cooling failed to keep up, and I watched power steadily go up until the system eventually crashed!

Frankly, I’m tired of these shenanigans. I understand the desire to make a board appear better than the competition, and I’m not even opposed to auto-overclocking features. Just at least give us a way to run a CPU at fully stock specifications. Because sometimes we actually want to respect the official TDP constraints.

This technically voids your AMD CPU warranty, just like Precision Boost Overdrive.