AMD Threadripper 3990X Review: A 64-Core Multithreaded Beast Unleashed

We also spent some time overclocking the 3nd Generation AMD Ryzen Threadripper 3990X to see what kind of additional horsepower we could wring from the massive processor...

Overclocking The AMD Ryzen Threadripper 3990X Pushing Zen+ Beyond Stock

Manually overclocking a 3nd Generation Ryzen Threadripper processors is very similar to the previous-gen 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 fine tune the end result if you like to tinker and go the manual route. However, the easiest to achieve the most gain will come from tweaking multipliers.
As was the case with the previous-gen Threadrippers, overclocking can be done from within the BIOS on enthusiast motherboards or via AMD's Ryzen Master utility, though we should point out that a compatible version of Ryzen Master wasn't available for review. We're told a new version will be uploaded to AMD's site today, but it is not available as of the time of this publication. Due to the fact that a compatible version of Ryzen Master wasn't available, we manually overclocked our processor via the system BIOS. When manually overclocking Ryzen Threadripper processors (and mainstream Ryzen processors), however, you lose support for features like Precision Boost and essentially lock the processors at a given max frequency, which may actually be lower than the maximum single-core Boost frequency. As such, you may be giving up some single-threaded performance if you manually overclock. 

Like 2nd Gen Ryzen processors though, these new chips should support Precision Boost Overdrive and Automatic Overclocking within Ryzen Master. With PBO, frequencies are dynamically adjusted and automatically managed, because SenseMI is left in control of the processor, and all of the clock gating and power conserving features in the processors continue to function. PBO also reads data embedded in the BIOS by motherboard manufacturers that outlines the maximum power limits of that particular board. Flip on PBO in Ryzen Master, crank up the power targets in-line with your motherboard's capabilities and your system's cooling, and overall system performance should be increased.  Auto Overclocking works similarly, just flip it on an go. Again, assuming you've got adequate cooling (cooling duties in out test system were handled by a Thermaltake 360mm AiO liquid cooler).

For out overclocking tests, we experimented with different CPU multipliers, increasing the all-core clock, until our test system was no longer stable or began thermal throttling under extended load. If you look closely at the Cinebench screenshot above, there are multiple results available as we increased the multiplier. This chart below reflects the maximums table all-core boost we were able to achieve with our setup, of 3.95GHz or a multiplier of 39.5X.  Windows would boot with an all-core boost of 4.1GHz, but we couldn't reliably repeat any benchmarks and had a couple of thermal shutdowns as the CPU exceeded 100°C.

As you can see, we were able to push the Threadripper 3990X's Cinebench score to over 30K. That's more than double the performance of Intel's Xeon W-3175X 28-core processor and nearly 6x the performance of a Core i9-9900KS.

Total System Power Consumption Tested at the Outlet

Throughout all of our benchmarking and testing, we also monitored how much power our 3rd Gen 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.

As we've seen with all 3rd Gen Ryzen processors so far, idle power is somewhat high relative to other platforms. Load power with the Threadripper 3990X while running in its stock configuration, however, isn't much higher than the 3970X, despite the 3990X having twice as many cores. The 3990X's frequency and voltage curve is obviously more tame than the 3970X, but AMD is likely binning and using only premium dies on this processor and, of course, limiting power to maintain socket compatibility.

We also monitored power while overclocking and saw a massive increase in consumption. For these tests, we did not alter the CPU voltage at all -- that was left on Auto and we simply altered the processor's multiplier. In its stock configuration, we saw all-core clocks under load hover around 3.05GHz. Upping the all-core clock to 3.5GHz added about 240W. Increasing further to 3.7GHz pushed it up by nearly 300W. And going all the way up to 3.95GHz increased power consumption by 537 Watts. With all of those cores under the hood running at full-tilt, a large increase in power consumption is expected, but needless to saw, a top-notch power supply and motherboard is an absolute must if you plan to do any tweaking with a Threadripper 3990X.

Let's consider all the data and testing, and sum things up for the new 64-core Threadripper, next...