Thermal Design Power, or TDP, is a term used by AMD and Intel to refer in an extremely broad sense to the rate at which a CPU cooler must dissipate heat from the chip to allow it to perform as advertised. Sort of. Depending on the specific formula and product, this number often ends up a combination of science-y variables and voodoo mysticism, ultimately culminating in a figure that’s used to beat-down forum users over which processor has a lower advertised “TDP”. With the push of Ryzen 3000, we’re focusing today on how AMD defines TDP and what its formula actually breaks into, and how that differs from the way cooler manufacturers define it. Buying a 95W TDP processor and a 95W TDP CPU cooler doesn’t mean they’re perfectly matched, and TDP is a much looser calculation than most would expect. There’s also contention between cooler manufacturers and CPU manufacturers over how this should be accurately calculated versus calculated for marketing, something we’ll explore in today’s content.
This content comes from an earlier-published feature-length video we made. We don’t really make any profit on the articles, but maintain them anyway as a point of reference. If you’d like to support deep-dive, long-form content like this, please consider supporting us the following ways:
- Watching the video is a great way, but we know that you’re here because you prefer reading! It’s faster, after all
- Grabbing a GamersNexus GPU Disassembly Toolkit, an anti-static GN Modmat (available in medium & classic large), T-shirt, GPU anatomy poster, glassware, or other merch to support us
- Contributing to our efforts on Patreon
The article continues after the embedded video. Please note that some off-the-cuff/unscripted commentary will not be ported to the article, so you may miss on some commentary, but most of it is here.
Other than announcing our upcoming collaborative stream with overclocker Joe Stepongzi (Bearded Hardware), we're also talking Threadripper specification leaks, 6000MHz memory overclocking, RDNA 2 and Zen 3 roadmap information, and smaller items. For us, though, we're excited to announce that we're streaming some liquid nitrogen extreme overclocks with AMD parts this weekend. We haven't run both the 5700 XT and 3900X under liquid nitrogen at the same time, so we'll be doing that on Sunday (9/15) at 1PM Eastern Time (NYC time). On Saturday (9/14), we'll be streaming the efforts to overclock just the 3900X under liquid nitrogen. Joe Stepongzi, pro overclocker with a decade of experience in the 'sport,' will be joining us to help run the show.
Memory speed on Ryzen has always been a hot subject, with AMD’s 1000 and 2000 series CPUs responding favorably to fast memory while at the same time having difficulty getting past 3200MHz in Gen1. The new Ryzen 3000 chips officially support memory speeds up to 3200MHz and can reliably run kits up to 3600MHz, with extreme overclocks up to 5100MHz. For most people, this type of clock isn’t achievable, but frequencies in the range of 3200 to 4000MHz are done relatively easily, but then looser timings become a concern. Today, we’re benchmarking various memory kits at XMP settings, with Ryzen memory DRAM calculator, and with manual override overclocking. We’ll look at the trade-off of higher frequencies versus tighter timings to help establish the best memory solutions for Ryzen.
One of the biggest points to remember during all of this -- and any other memory testing published by other outlets -- is that motherboard matters almost more than the memory kit itself. Motherboards are responsible for most of the timings auto configured on memory kits, even when using XMP, as XMP can only store so much data per kit. The rest, including unsurfaced timings that the user never sees, are done during memory training by the motherboard. Motherboard manufacturers maintain a QVL (Qualified Vendor List) of kits tested and approved on each board, and we strongly encourage system builders to check these lists rather than just buying a random kit of memory. Motherboard makers will even tune timings for some kits, so there’s potentially a lot of performance lost by using mismatched boards and memory.
Hardware news this past week has only partially slowed, with an uptick in security notices responsible for most of the coverage we've found interesting. Researchers at Eclypsium have identified vulnerabilities in more than 40 drivers from 20 different vendors, something we'll talk about in today's coverage. We also talk about Ryzen 3000 binning statistics posted by Silicon Lottery, the CPU binning company.
Show notes continue after the embedded video.
This is a quick and straightforward piece inspired by a Reddit post from about a week ago. The reddit post was itself a response to a video where a YouTuber claimed to be lowering temperatures and boosting performance on Ryzen 3000 CPUs by lowering the vcore value in BIOS; we never did catch the video, as it has since been retracted and followed-up by the creator and community with new information. Even though the original content was too good to be true, it was still based on a completely valid idea -- lowering voltage, 50% of the equation for power -- will theoretically reduce thermals and power load. The content ended up indirectly demonstrating some unique AMD Ryzen 3000 behaviors that we thought worth testing for ourselves. In this video, we’ll demonstrate how to know when undervolting is working versus not working, talk about the gains or losses, and get some hard numbers for the Master and Godlike motherboards.
With the launch of the Ryzen 3000 series processors, we’ve noticed a distinct confusion among readers and viewers when it comes to the phrases “Precision Boost 2,” “XFR,” “Precision Boost Overdrive,” which is different from Precision Boost, and “AutoOC.” There is also a lot of confusion about what’s considered stock, what PBO even does or if it works at all, and how thermals impact frequency of Ryzen CPUs. Today, we’re demystifying these names and demonstrating the basic behaviors of each solution as tested on two motherboards.
Precision Boost Overdrive is a technology new to Ryzen desktop processors, having first been introduced in Threadripper chips; technically, Ryzen 3000 uses Precision Boost 2. PBO is explicitly different from Precision Boost and Precision Boost 2, which is where a lot of people get confused. “Precision Boost” is not an abbreviation for “Precision Boost Overdrive,” it’s actually a different thing: Precision Boost is like XFR, AMD’s Extended Frequency Range boosting table for boosting a limited number of cores when possible. XFR was introduced with the first Ryzen series CPUs. Precision Boost takes into account three numbers in deciding how many cores can boost and when, and those numbers are PPT, TDC, and EDC, as well as temperature and the chip’s max boost clock. Precision Boost is enabled on a stock CPU, Precision Boost Overdrive is not. What PBO does not ever do is boost the frequency beyond the advertised CPU clocks, which is a major point that people have confused. We’ll quote directly from AMD’s review documentation so that there is no room for confusion:
AMD’s X570 chipset marks the arrival of some technology that was first deployed on Epyc, although that was done through the CPU as there isn’t a traditional chipset. With the shift to PCIe 4, X570 motherboards have grown more complex than X370 and X470, furthered by difficulties cooling the higher power consumption of X570. All of these changes mean that it’s time to compare the differences between X370, X470, and X570 motherboard chipsets, hopefully helping newcomers to Ryzen understand the changes.
The persistence of AMD’s AM4 socket, still slated for life through 2020, means that new CPUs are compatible with older chipsets (provided the motherboard makers update BIOS for detection). It also means that older CPUs (like the reduced price R5 2600X) are compatible with new motherboards, if you for some reason ended up with that combination. The only real downside, aside from potential cost of the latter option, is that new CPUs on old motherboards will mean no PCIe Gen4 support. AMD is disabling it in AGESA at launch, and unless a motherboard manufacturers finds the binary switch to flip in AGESA, it’ll be off for good. Realistically, this isn’t all that relevant: Most users will never touch the bandwidth of Gen4 for this round of products (in the future, maybe), and so the loss of running a new CPU on an old motherboard may be outweighed by the cost savings of keeping an already known-good board, provided the VRM is sufficient.
AMD’s technical press event bore information for both AMD Ryzen and AMD Navi, including overclocking information for Ryzen, Navi base, boost, and average clocks, architectural information and block diagrams, product-level specifications, and extreme overclocking information for Ryzen with liquid nitrogen. We understand both lines better now than before and can brief you on what AMD is working on. We’ll start with Navi specs, die size, and top-level architectural information, then move on to Ryzen. AMD also talked about ray tracing during its tech day, throwing some casual shade at NVIDIA in so doing, and we’ll also cover that here.
First, note that AMD did not give pricing to the press ahead of its livestream at E3, so this content will be live right around when the prices are announced. We’ll try to update with pricing information as soon as we see it, although we anticipate our video’s comments section will have the information immediately. UPDATE: Prices are $450 for the RX 5700 XT, $380 for the RX 5700.
AMD’s press event yielded a ton of interesting, useful information, especially on the architecture side. There was some marketing screwery in there, but a surprisingly low amount for this type of event. The biggest example was taking a thermographic image of two heatsinks to try and show comparative CPU temperature, even though the range was 23 to 27 degrees, which makes the delta look astronomically large despite being in common measurement error. Also, the heatsink actually should be hot because that means it’s working, and taking a thermographic image of a shiny metal object means you’re more showing reflected room temperature or encountering issues with emissivity, and ultimately they should just be showing junction temperature, anyway. This was our only major gripe with the event -- otherwise, the information was technical, detailed, and generally free of marketing BS. Not completely free of it, but mostly. The biggest issue with the comparison was the 28-degree result that exited the already silly 23-27 degree range, making it look like 28 degrees was somehow massively overheating.
Let’s start with the GPU side.
As we’ve been inundated with Computex 2019 coverage, this HW News episode will focus on some of the smaller news items that have slipped through the cracks, so to speak. It’s mostly a helping of smaller hardware announcements from big vendors like Corsair, NZXT, and SteelSeries, with a side of the usual industry news.
Be sure to stay tuned to our YouTube channel for Computex 2019 news.
Computex is coming up. We'll be at the show next week, which means most of our time will likely be spent covering new X570 motherboards for AMD and AMD's announcements, with NVIDIA's presence sparse at the show and Intel's focused on mobile. Beyond the motherboards and CPUs, we already have numerous cooler and case manufacturers lined-up for meetings, alongside some GPU board partners. In the meantime, this past week has set the stage for Computex with a focus on security vulnerabilities, tariffs, and X570 chipset sightings.
The show notes are below the embedded video.
We moderate comments on a ~24~48 hour cycle. There will be some delay after submitting a comment.