AMD 2nd Gen Ryzen Threadripper 2950X And 2990WX Review: Beastly Zen+ Many-Core CPUs
AMD Ryzen Threadripper 2950X & 2990WX: Overclocking And Power Consumption
We also spent some time overclocking the 2nd Generation Ryzen Threadrippers (sort of) to see what kind of additional horsepower the processor had lurking under their heat spreaders...
Overclocking a 2nd Generation Ryzen Threadripper processor is very similar to the original parts. Because the processors are unlocked, overclocking it is simply a matter of altering a few multipliers, tweaking voltages, and dealing with the additional heat and power requirements. These processors can also be overclocked by adjusting base clock frequencies though, so it's possible to really fine tune the end result if you like to tinker and go the manual route.
As was the case with the first-gen Threadrippers, overclocking can be done from within the BIOS on enthusiast motherboards or via AMD's Ryzen Master software. Ryzen Master gets a major update with this launch, however, that's probably going to be appealing to those of you that would like to maximize performance on a Threadripper, without sacrificing some of its more advances features.
Along with the features added in v1.3 that arrived alongside the 2nd Generation Ryzen desktop processors, like power tracking, fastest core detection, and per CCX overclocking, the latest version of Ryzen Master -- version 1.4 -- includes these additional updates. We'll quote AMD directly to keep it simple...
- Precision Boost Overdrive (PBO): PBO allows the SoC to consume more power from the socket, and exploits additional current headroom in motherboards with VRM configurations that exceed AMD specification.
- Topology View: Cores in the UI are now labeled and grouped according to their physical location in the SoC.
- Quarter Core Mode: Legacy Compatibility Mode has been extended to include a 75% thread count reduction, permitting the 2990WX to temporarily behave like a Ryzen 7 2700X CPU with 2 CCX, 8C16T, and 2CH DIMMs.
Precision Boost Overdrive, or PBO, is particularly interesting. When manually overclocking Ryzen and Ryzen Threadripper processors, you lose support for Precision Boost and essentially lock the processors at a given max frequency, which may actually be lower than the maximum single-core Precision Boost frequency. With PBO, however, frequencies are dynamically adjusted and automatically managed, SenseMI is left in control of the processor, and Precision Boost continues to function. PBO reads data embedded in the BIOS by motherboard manufacturers that outlines the maximum power limits of that particular board. Simply flip on PBO in Ryzen Master, crank up the power targets, and bingo -- you've increased system performance.
Because PBO is so easy to use and maintains the processors' feature set when enabled, we used it for our overclocking tests. This is a somewhat conservative approach to overclocking a Threadripper and should give you all an idea as to the “worst case scenario” overclock. Our results should be repeatable, assuming you’ve got similar hardware and everything is working properly. Cooling duties were handled by a Thermaltake 360mm self-contained liquid cooler.
To see what our chips could do, we enabled PBO and increased the power targets to the maximum values available with our motherboard (these values will vary from board to board depending on the robustness of its VRM and VRM cooling solution). During our endeavor, we should note that the processors operated in the 80-degree range when under sustained load, and idle temperatures hovered in the upper 30s, so temps were not an issue.
While we had PBO enabled, we re-ran a couple of benchmarks and saw some marked performance improvements. We nearly hit 6,000 in Cinebench's MT test with the Threadripper 2990WX and the 2950X was able to overtake the Core i9-7980XE. The 3DMark Fire Strike Physics test also showed some gains for both chips, though the high marks from the 2990WX were achieved in 1/2 core mode.
We should also mention that with the power targets cranked all the way up with the Threadripper 2990WX, our test rig wasn't stable in Cinebench, so we dialed things back by about 15%. Higher scores with PBO enabled on a 2990WX should be possible with some motherboards. During our briefings for example, we witnessed a 2990WX installed in an MSI MEG X399 Creation, air-cooled by a Wraith Ripper, nearly hit 6,100 in Cinebench.
Throughout all of our benchmarking and testing, we also monitored how much power our 2nd Gen Ryzen Threadripper test system was consuming with a power meter, versus the other systems we used for benchmark comparisons.
Our goal was to give you an idea as to how much power each configuration used while idling at the Windows desktop and while under a heavy CPU workload. Keep in mind, this is total system power consumption being measured at the outlet and not the the individual power of the CPUs alone.
Just like we saw with the originals, idle power with the 2nd Generation Threadripper configurations was higher than all of the other systems tested. Under load, power consumption was also higher than the other platforms, but the 2950X was not completely out of line with Intel's highest-end Core i9. The Threadripper 2990WX, however, consumed significantly more power than Intel's most powerful desktop chip. The 2990WX also offered 50% better performance in most multi-threaded tests and is packing quad, 8-core dies though, so increased power consumption isn't unexpected.
We also monitored power while overclocking and saw some huge jumps in consumption. While overclocked, the Threadripper 2950X's peak power consumption under load jumped up by nearly 90 watts. The Threadripper 2990WX's power increased by nearly 200 watts, however, and as we mentioned earlier, that wasn't even with the power targets cranked all the way up to their absolute maximum. Moral of the story -- make sure you've got a robust motherboard and power supply and a beefy cooler if you plan to overclock a 32-core Threadripper.