AMD Ryzen CPU & platform guide
AMD’S CLAWED ITS WAY BACK INTO THE PREMIUM CPU MARKET WITH ITS NEW RYZEN PROCESSORS — BUT ARE ITS NEW 8-CORE WONDERS READY FOR THE BRUTALITY OF PRIMETIME? JOSH COLLINS INVESTIGATES.
Welcome back!” That’s the general feeling that’s been flowing from the enthusiast community towards AMD with the launch of its new Ryzen CPUs. Based on chipmaker’s Zen microarchitecture, Ryzen’s been paired with the equally new AM4 platform, utilising a range of chipsets. But it’s been a long while since AMD had a CPU of this calibre, so let’s rewind a bit. Perhaps, even a byte.
THE LONG TEASE
In case you’ve been living in the woods with no internet for the past two years, or perhaps you don’t follow the speculative PC enthusiast news game very much, by this stage, you have no doubt at least heard or read about AMD’s new Zen microarchitecture, in development for several years. Now, after much waiting and anticipation, the products have finally landed: a new range of CPUs and a swathe of motherboard chipsets.
Zen is AMD’s first new microarchitecture in five years. Furthermore, the design is a clean sheet design, deriving no inherent values from previous microarchitectures from the company.
This launch is centred primarily around the introduction of AMD’s new top-of-the-line CPU range called Ryzen 7, spearheaded by the Ryzen 7 1800X, and five new chipsets covering the needs of enthusiasts, business, consumers and even small form factor specific solutions. These new chipsets
are the X370, B350, A320, X300 and A300. The roundup following this piece covers an offering of X370 and B350 based motherboards. For a breakdown of chipset features, check out the table we’ve prepared comparing the feature support across the new range.
The new CPU microarchitecture, Zen, is the brainchild of an AMD luminary and chip guru, Jim Keller, backed by his engineering team.
THE PATH TO RECOVERY
The last time AMD had a wholly competitive processor range it was the early 2000s and AMD was giving the blue giant, Intel, a run for its money with its highly efficient Athlon (codenamed K7) and Athlon-64 (K8) processors. There’s no surprise, then, when you link the dots to find Jim Keller worked on the Athlon design and was the lead architect for Athlon-64, including co-authoring the specs for the x86-64 instruction set widely used for 64-bit processing on x86 based architectures — even Intel use this.
After the K8 generation, Jim Keller moved on to work for other chip manufacturers such as Broadcomm and Apple, contributing to a range of devices, including the Apple A4 and A5 ‘system on a chip’ (SoC) designs.
The microarchitecture prior to Zen was Bulldozer and saw three revisions in the form of Piledriver, Steamroller and Excavator. All iterations failed to impress against the ever strengthening and evolving Core microarchitecture from Intel. For quite some time, the performance CPU market was a onehorse race, with AMD relegated to the entry-level market.
News broke in 2012 of Keller leaving Apple and resuming a role within AMD, tasked with developing a new generation microarchitecture from a clean sheet. The industry felt an instant buzz. Could AMD return to challenge Intel, which by now had grown to enjoy its market perceived position as CPU leader with minimal competition? We all wanted answers.
For three years, Keller and his team developed the new architecture, followed by 18–24 months of refinement. Though Keller left AMD again in 2015 for new opportunities at Tesla, it wasn’t before having laid the Zen groundwork. As such, we can be sure the roadmap will continue to be paved in Zen, just as Intel has tweaked its Core microarchitecture since its launch of the Core i7 in 2008, codenamed Nehalem.
A CLEAN SHEET
With a clean sheet from which to derive AMD’s future in the x86 microprocessor industry, there was a formidable task ahead of Keller and his team. A whole new CPU microarchitecture, starting from scratch, is no easy feat and to deliver a solution that not only closed a very considerable performance gap between AMD and Intel but to try to deliver it as quickly as possible can only be summarised as a mammoth task.
While abandoning AMD’s previous processors increased the work to be done, it equally removed constraints from the development programme. As such, Keller was free to consider how the CPU would operate and interact with other sub-systems within the platform, along with the current and future needs of a broad range of users and usage scenarios. Essentially, a scalable solution would be ideal, paired with numerous integrated features.
Keller was instrumental in the development of SoC processor designs for Apple. Notably, the Apple A4 and A5 development lead by Keller and found in products like the iPhone 4 and 4S. Therefore, it’s not unusual to see one of the significant core differences between Zen based CPUs and its predecessors is the implementation of a SoC design.
This approach encouraged an outcome that would deliver a powerefficient and scalable processor with increased interconnect bandwidth for platform sub-systems. Paired with an efficient core processing capability and the subsequent processor microarchitecture has already left a noticeable impression at launch.
A CAUSE FOR DISRUPTION
Based on a SoC design, the controllers for memory, PCI Express, SATA and USB sub-systems are all incorporated into the same package as the processor cores. This introduces increased bandwidth between sub-systems and improved power efficiency. However, this occurs at the cost of creating a significantly more complex chip and impacting die area availability.
The SoC design provides flexibility for adaptation across a variety of uses from mobile to small factors, desktops to servers. This scalability also provides flexibility in how the SoC can be integrated into different platforms with varying goals. For example, the same technology can be used to create a fully featured small form factor (SFF) solution while also providing the backbone for a multi-CPU scaling server cluster. Add simultaneous multithreading and it’s like icing on a cake.
The disruptive nature of the Zen platform isn’t just through design. AMD has aggressively targeted Intel in an effort to not only regain market share but to also regain lost mind share. With the AMD Ryzen 7 1800X and AM4 X370 solution poised to do battle head-on with Intel’s established Core i7 6900K and X99 platform, performance alone wouldn’t be enough. Smart planning has seen the Ryzen 7 1800X enter the market at nearly half the price of the Core i7 6900K and with supporting motherboards on average significantly cheaper. The challenge has been made.
RYZEN 7 1800X AND AM4 TESTED
Our scope of attack was to first assess stock performance. This meant stock CPU frequencies, stock platform frequencies (no bus adjustments) and the vendor referenced, JEDEC backed, stock RAM frequency. In a nutshell, this saw the Ryzen 7 1800X operating predominantly between 3.6–3.7GHz with spikes to 4.0GHz and memory running at DDR4-2666. This setup went head-to-head with numerous Intel CPUs from both the Z- and X-platform and operating with DDR4-2400 RAM. The Core i7 7700K consistently boosted to 4.5GHz and the Core i7 6900K and 6950X both at stock frequencies and boosting to 4.0GHz. The X-platform provided the most comparable stage for assessing the 1800X, even more so when we re-ran tests with the 1800X overclocked and locked to 4.0GHz.
The 7700K delivered the highest level of gaming performance. However, upon closer inspection, the gap to the 1800X wasn’t as big as expected and demonstrated that if AMD can refine the design to increase overall clock speeds of Ryzen, then a hidden strength could be revealed. As expected, the 7700K was cut down in Cinebench, yet held its own in the X265 encoding benchmark.
The Ryzen CPU went toe-to-toe with the X-platform offerings, and while it wasn’t the outright fastest of the bunch, what the 1800X did do was embarrass the price point of the Intel offerings. To put this into perspective, a 6900K plus X99 motherboard will cost twice as much for the equivalent 1800X plus X370 motherboard. We hope you’re sitting down for this next one: you could build a whole Ryzen PC for the price of the Core i7 6950X alone, much less a motherboard to match it. This is what defines the Ryzen release. For most enthusiasts, an AMD platform wasn’t up for consideration. Now, however...
The second course of enquiry set out to observe the same scenarios but with increased memory frequency, with operational frequencies between DDR4-3000 and DDR4-3200. This is when Ryzen started to falter. Initially just reaching DDR4-2933 or DDR4-3200 — native memory frequencies for Ryzen — was a nightmare, but towards the end of the assessment period, we got DDR4-3200, but stability was sketchy.
This demonstrates that AMD’s new platform has some teething issues as it settles into the marketplace. We expected this and it was reminiscent of Intel’s big shift from Core 2 Quad-X48 to Core i7-X58. It also shows that AMD and motherboard vendors are acting quickly to patch issues found preand post-launch and this should be looked upon in a positive light, rather than negative.
Therefore, we plan to revisit Ryzen in the next couple of months, with a specific focus on DDR4-2933 and DDR4-3200 support. We will also have Ryzen 5 insights for you then as well. Stay tuned!