AMD Raven Ridge Thermal/Power Analysis: Ryzen CPUs With Vega

Combined Stress Testing: Benchmarks & Results

Extreme Stress Test with the Stock Cooler

The individual CPU and GPU stress tests pushed AMD's stock thermal solution to its limit. So what happens when we tax both sides of Raven Ridge simultaneously? How well are the two blocks balanced, what does maximum power consumption look like, and how much heat is generated?

Once again, this represents an extreme scenario that doesn’t have much to do with either processor's everyday operation. One way or another, though, both chips have to survive the gauntlet.

AMD Ryzen 3 2200G

After ~6 minutes, AMD’s Ryzen 3 2200G hits 95°C. That's well above its thermal limit. And the result doesn't change, even when we push the fan to its fastest rotational speed. With that said, the processor doesn't falter; it keeps going, albeit at an uncomfortably high temperature.

The hottest voltage converters toe the 80°C mark. Average power consumption is close to 88W, while peak power use falls just shy of the 100W threshold.

Plotting frequency over time shows us that the Zen cores slow down slightly once the processor exceeds 94.5W. However, Ryzen does balance this demanding workload well; the missing 100 MHz toward the end of our test is no big deal, particularly since Radeon Vega Graphics isn't affected at all.

In the end, AMD's stock cooler passes our test in a photo finish, with the Zen cores dialing back just a touch.

AMD Ryzen 5 2400G

The higher-end Ryzen 5 2400G enjoys greater utilization via simultaneous multi-threading and features more Stream processors. Surely it'll hit a wall when we push it hard, right? An average power consumption measurement of ~99W over 15 minutes and peaks close to 128W just can't be dealt with using a small aluminum sink.

Sure enough, after about three minutes, the CPU starts throttling to protect itself. After that, temperatures peak around 92°C, and the voltage converters run at 80°C.

Our corresponding frequency curve shows the throttling kick in even more clearly. The controller tries to maintain balance by frantically bumping clock rates up and back down. After two minutes of failing to rein in thermals, the temperature hits 95°C and AMD's Ryzen 5 2400G pulls the emergency brake. A small frequency dip affects the CPU and GPU, bringing voltage and current down a bit.

After the processor frantically changes the CPU’s frequency (near its thermal limit), it can achieve the original higher clock rate again after a short cooling-off period without a load. However, as soon as the graphics engine throttles, it takes a reboot to recover full functionality. Even a prolonged idle period doesn't help. AMD couldn't (or wouldn't) explain the cause of this behavior.

Extreme Stress Test with the Chiller

Enough of that diminutive stock heat sink and fan. We’re switching to our chiller and a good CPU water block to eliminate thermal bottlenecks. Even under full load, the liquid stays at a constant 20°C, while the air-conditioned room provides 22°C to the blower running at full-blast.

AMD Ryzen 3 2200G

Cooling the Ryzen 3 2200G wasn't a challenge for our massive thermal solution. Consequently, we never had an issue with heat. Average power consumption through our 15-minute run was ~90W, with peaks approaching ~101W. In spite of this, the processor's temperature never exceeded 57°C, and the voltage converters peaked at ~62°C.

The CPU and GPU frequencies remain stable. This means it's possible to circumvent AMD's throttling mechanism on the lower-end 2200G, even under brutal loads, by using an ample cooler. You just need something better than the Wraith Stealth.

AMD Ryzen 5 2400G

But what's this? Ryzen 5 2400G shows us that the chip's throttling behaviors can't be attributable to thermal limits. CPU and GPU temperatures in the 60°C range don't require corrective action by the processor's telemetry. And yet, we again see Ryzen 5 pull its emergency chute, dropping average power consumption from just over 114W (with up to 131W peaks) to ~100W. The voltage converters were at a mere 64°C before the processor started throttling.

Clock rates plotted over time illustrate the drop as well, though they're not as pronounced as our thermal readings. Both the CPU and GPU lose ~100 MHz. And again, it takes a reboot for Ryzen 5 2400G’s frequencies to hit their ceilings once this behavior starts. Simply giving the chip a break to cool off doesn't restore full functionality.

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