Threadripper 3990x brings more CPU threads than Windows Pro can handle [arstechnica.com]
As reported in Anandtech's excellent Threadripper 3990x review [anandtech.com], the newest Threadripper is also pushing the boundaries of what the industry is prepared to consider a "desktop" in the first place. Windows 10 Professional chokes pretty badly when presented with TR3990x's 128 logical processors (threads) and organizes them as two CPU groups—which it even mistakenly refers to as multiple "sockets" in some places.
Windows 10 Pro's lack of support for so many threads on a single socket isn't just a funny-looking quirk. Under Windows 10 Pro, some benchmarks run twice as fast with hyperthreading disabled, just to keep the operating system from maladaptively grouping them into separate "sockets" that then get handled under NUMA [wikipedia.org] rules. Keeping threads from crossing real physical processor boundaries is helpful, but it can be crippling when the actual boundary doesn't exist in the first place.
Ultimately, this means Windows 10 Pro isn't really appropriate for Threadripper 3990x at all—if you're building a 3990x system, you need to plan on a roughly $120 upgrade from Pro to Workstation or on paying the $84/year for a Windows 10 Enterprise subscription. Windows 10 Workstation and Enterprise both support TR3990x's 128 threads without resorting to organizing them in nonexistent sockets, and without the performance penalties associated.
None of this is a problem for Linux users. Although Intel's performance-optimized Clear Linux distribution outperforms [phoronix.com] normal "daily driver" distributions, it doesn't do so any more on the Threadripper 3990x than it does on a lowly quad-core [forbes.com] Ryzen 5 3400G. If you want to run a 3900x on bone-stock Ubuntu, you can do so, and you'll be fine.
One of the interesting takeaways from my pre-launch briefing with AMD on the Ryzen Threadripper 3990X [phoronix.com] was AMD representatives actually recommending Clear Linux [phoronix.com] for use on this 64-core / 128-thread HEDT processor and the platform to which they've found the best performance. Yet, Clear Linux is an Intel open-source project. In any case, here are benchmarks of how Clear Linux performs against other Linux distributions on the Ryzen Threadripper 3990X within the System76 Thelio Major. And, holy crap, with the Threadripper 3990X on Clear Linux I managed to build the x86_64 default Linux kernel in under 20 seconds!
The Clear Linux recommendation for the Threadripper 3990X was hardly a surprise to me given my experience with the platform, just a bit surprising AMD representatives acknowledging the Intel open-source software creation during a briefing. We've been benchmarking Clear Linux for years and were the ones to initially shine the public spotlight on its impressive performance capabilities -- that includes for AMD platforms too with numerous tests on different platforms we've performed the past few years. Just recently were our benchmarks looking at how Clear Linux offered the best performance on a $199 AMD laptop [phoronix.com] while this testing is at the opposite end of the spectrum with the 64-core $3990 USD processor.
Previously: AMD's 64-Core Threadripper 3990X Reviewed [soylentnews.org]