AMD yesterday released a community update with interesting assertions regarding thread scheduling, temperature reporting, Windows power plan issues, and SMT challenges.
According to AMD’s Robert Hallock, the company has found no indication that Windows 10 thread scheduling is operating improperly for Zen. This should be the final word in any argument that Microsoft thread scheduling issues are sabotaging Ryzen: they aren’t, as stated by AMD below:
“We have investigated reports alleging incorrect thread scheduling on the AMD Ryzen processor. Based on our findings, AMD believes that the Windows 10 thread scheduler is operating properly for ‘Zen,’ and we do not presently believe there is an issue with the scheduler adversely utilizing the logical and physical configurations of the architecture.
“As an extension of this investigation, we have also reviewed topology logs generated by the Sysinternals Coreinfo utility. We have determined that an outdated version of the application was responsible for originating the incorrect topology data that has been widely reported in the media. Coreinfo v3.31 (or later) will produce the correct results.”
When we first began benchmarking Ryzen CPUs, we already had a suspicion that disabling simultaneous multithreading might give a performance boost in games, mirroring the effects of disabling hyperthreading (Intel’s specific twist on SMT) when it was first introduced. Although hyperthreading now has a generally positive effect in our benchmarks, there was a time when it wasn’t accounted for by developers—presumably partly related to what’s happening to AMD now.
In fact, turning SMT off offered relatively minor gaming performance increases outside of Total War: Warhammer—but any increase at all is notable when turning off a feature that’s designed to be positive. Throughout our testing, the most dramatic change in results we saw were from overclocking, specifically on the low stock frequency R7 1700 ($330). This led many readers to ask questions like “why didn’t you test with an overclock and SMT disabled at the same time?” and “how much is Intel paying you?” to which the answers are “time constraints” and “not enough, apparently,” since we’ve now performed those tests. Testing a CPU takes a lot of time. Now, with more time to work on Ryzen, we’ve finally begun revisiting some EFI, clock behavior, and SMT tests.
As with any new technology, the early days of Ryzen have been filled with a number of quirks as manufacturers and developers scramble to support AMD’s new architecture.
For optimal performance, AMD has asked reviewers to update to the latest BIOS version and to set Windows to “high performance” mode, which raises the minimum processor state to its base frequency (normally, the CPU would downclock when idle). These are both reasonable allowances to make for new hardware, although high-performance mode should only be a temporary fix. More on that later, though we’ve already explained it in the R7 1700 review.
This is quick-and-dirty testing. This is the kind of information we normally keep internal for research as we build a test platform, as it's never polished enough to publish and primarily informs our reviewing efforts. Given the young age of Ryzen, we're publishing our findings just to add data to a growing pool. More data points should hopefully assist other reviewers and manufacturers in researching performance “anomalies” or differences.
The below is comprised of early numbers we ran on performance vs. balanced mode, Gigabyte BIOS revisions, ASUS' board, and clock behavior when under various boost states. Methodology won't be discussed here, as it's really not any different from our 1700 and 1800X review, other than toggling of the various A/B test states defined in headers below.
AMD was clear from the beginning of today’s Capsaicin and Cream event that it was not a Vega product launch (the only 100% new Vega news was that the GPU would be officially branded “Vega”), but demos of the previously mentioned technologies like high-bandwidth cache controller and rapid-packed math were shown.
After some brief discussion about exactly how much alcohol was consumed at last year’s afterparty, the Vega portion of the presentation covered three major points: HB Cache Controller, Rapid Packed Math, and Virtualization.
“Virtualization” in this context means the continued effort (by both AMD and NVIDIA) to make server-side gaming viable. AMD has partnered with LiquidSky and will be using Vega’s “Radeon Virtualized Encode” feature to make streaming games (hopefully) as latency-free as possible, though limitations on internet service still abound.
With the impending release of AMD Ryzen comes a wave of related product reveals. CyberPower is now offering preorders for several varieties of prebuilt PCs that take advantage of the new CPUs.
The four models below were described in CyberPower’s press release, and an additional four can be found on their website: the AMD Ryzen 7X Configurator, Mega Special III, Mega Special IV, and Winter Gaming Special II. Each of these configurations can be customized with alternate or additional parts, including “high-performance gaming memory, solid state drives, graphics cards, and gaming peripherals.” During the pre-sale, Corsair Hydro H60 AIO liquid coolers are included as a free upgrade, considering the limited launch-day support for AM4. CyberPower will in fact do a general “Pro OC” for a price, but there are plenty of free resources online for those interested.
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