The Ryzen Debut
The conundrum AMD currently faces started when it launched Bulldozer to lackluster reviews back in 2011. The following years found it trying to right the ship with Piledriver, Steamroller, and Excavator. But it’s safe to say the company's host processing portfolio never regained its lost luster. Meanwhile, Intel dominated the mobile, desktop, and server markets with a seemingly insurmountable performance built on the excellent Sandy Bridge design and an unrelenting cadence of incremental improvements.
Heading into today's review, nobody can argue the fact that AMD is far behind by comparison. Wouldn't that make a comeback all the more impressive, though?
We started seeing Zen micro-architecture teasers last year. Company representatives told us its next generation would usher in incredible performance gains, matching or surpassing Intel's best efforts on multiple fronts. Zen also promised to revitalize an aging platform through Socket AM4 and new core logic. And AMD says it has a clear path forward planned for future versions of Zen.
At some point, though, the rubber has to meet the road. A good first step was taking aim at a competitor. Intel's $1000+ Core i7-6900K seemed like an ambitious choice, but early hand-picked benchmark results made AMD's eight-core engineering samples look formidable. Then, announcing that the flagship model would sell for less than half of of the -6900K's price sent the masses into a frenzy. Most online vendors even sold out of their Ryzen 7 1800X allocation during pre-sales based on little more than AMD's own endorsement.
Now it's time for Ryzen to stand up on its own accord and show us what it can do in the real-world. We have several Ryzen SKUs in-house, spread across multiple Tom's Hardware labs. We've identified a number of unexpected results that bear continued investigation. We'll continue updating our coverage as answers materialize. But we want to start putting our findings in front of you so enthusiasts can make more informed buying decisions in the face of general availability, which begins today.
Four years ago, AMD began its work on the Zen core, which is its first clean-sheet architecture since Bulldozer. AMD’s initial objective was to transition from the 28nm process used for its modern APUs to GloablFoundries’ 14nm FinFET node, which offers increased performance and density within a similar power envelope. The company also set an ambitious goal to increase instruction-per-clock throughput by 40% over Excavator through a series of design choices that significantly boost performance. Notably, AMD deployed a new architecture and a lithography shrink simultaneously, which is a daunting challenge.
Last year, we published Everything Zen: AMD Presents New Microarchitecture At HotChips. In that story, we stepped through the composition of Zen, from front to back, right up to describing the CPU complex (CCX) responsible for housing four execution cores, each core's 512KB L2 cache, and 8MB of shared L3 cache. If you aren't already familiar with Zen and how it differentiates from prior-gen designs, check that piece out.
Moving forward, you need to know that the Zen core is Ryzen's fundamental building block. All three SKUs we're introducing today employ two quad-core CCXes, adding up to 4.8 billion transistors across the entire die. The company says its Infinity Fabric connects the CPU complexes, but remains shy about how that's a quantifiable benefit.
As we established in our architectural deep-dive, AMD also arms Zen with simultaneous multi-threading support, allowing each physical core to operate on two threads in parallel. In theory, this improves the utilization of available hardware resources. A lot of our real-world benchmarks bear that out with phenomenal performance gains. But other workloads expose teething pains we're still trying to diagnose.
How about the 40% IPC improvement goal AMD set for itself? Well, after factoring in the new micro-op cache (bypassing the L1 and L2 for frequently-accessed micro-ops), the better branch prediction engine, the 1.75x-larger instruction scheduler window, and faster caches, the company cites a +52% final tally compared to Excavator. Naturally, we have our own single-threaded workloads to run and will gladly make comparisons using CPUs from our lab.
The Ryzen 7 Line-Up
AMD is splitting its newest CPUs into the eight-core Ryzen 7 family, a six-core Ryzen 5 series, and the quad-core Ryzen 3 line-up. Only the Ryzen 7 SKUs are shipping today, but it's easy to see that AMD is targeting Intel's Core i7, i5, and i3 portfolios with a similar naming scheme.
Aside from Intel's eight- and 10-core i7s, the Ryzen 7s deliver higher core counts across the board. The AMD CPUs also blow Intel's Broadwell-E prices out of the water, though four-core/eight-thread Kaby Lake is generally cheaper (albeit with half as many cores).
It's not entirely clear what features AMD plans to roll out across the Ryzen 5 and 3 CPUs, but we do know 7s sport the SenseMI suite. We'll go into more depth on SenseMI shortly. What's important here, though, is that SKUs with an X suffix include the eXtended Frequency Range capability. XFR automatically increases clock rate beyond the factory-set Precision Boost frequency if you provide additional thermal headroom with an aggressive cooler. This extra bit of speed applies to two of the chip's cores.
Ryzen 7 is solely a host processor, devoid of integrated graphics. All three models debuting today drop into the Socket AM4 interface, include eight physical cores, and boast 16MB of shared L3 cache. They also sport unlocked ratio multipliers, though you'll need a motherboard based on the X370, B350, or X300 chipsets to overclock.
The Ryzen 7 1800X features a 3.6 GHz base frequency able to hit 4 GHz under lightly-threaded workloads via Precision Boost technology. Both of those specifications are higher than Intel's eight-core Core i7-6900K. With Precision Boost enabled, all of the 1800X’s cores can operate at 3.7 GHz. And with enough thermal headroom, two cores jump as high as 4.1 GHz.
Perhaps surprisingly, given the comparisons to Intel's 140W Broadwell-E behemoths, 1800X bears a 95W TDP. If that's not enough to make you believe AMD has a new lease on life, the $500 price tag should excite professional content creators especially. Of course, if you don't regularly find yourself running heavily-threaded tasks, Ryzen 7's value isn't as pronounced. After all, Intel's Kaby Lake-based Core i5s and i7s offer solid performance and generally sell for less than the top-end AMD chips. Ryzen 7's performance in our benchmark suite will have to justify the premium.
The 95W Ryzen 7 1700X's clock rates drop to 3.4 GHz base and 3.8 GHz under Precision Boost. Those frequencies compare favorably against the 140W Core i7-6800K, which tops out at 3.6 GHz in lightly-threaded tasks and only comes equipped with six cores. Worse, Intel charges $425 for the -6800K, while AMD is introducing Ryzen 7 1700X at $400. The Core i7-7700K also becomes relevant at this point, with its $350 price tag.
AMD's Ryzen 7 1700 has a 65W TDP, making it the lowest-power eight-core desktop CPU available. A 3 GHz base clock rate and 3.7 Precision Boost ceiling are significantly lower than Intel's 91W Core i7-7700K. However, the company compensates with twice as many physical cores and a comparable price tag.
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The six-core/12-thread Ryzen 5 family should surface in Q2, and include at least two models. The Ryzen 5 1600X will feature a 3.6 GHz base and 4 GHz Precision Boost ceiling, while the 1500X is expected to start at 3.5 GHz and ramp up to 3.7 GHz in lightly-threaded workloads. AMD hasn't shared cache configurations yet for those models. Ryzen 3s are also in the queue, though those aren't expected until the second half of 2017.
AMD geared its pricing structure to target the 99% of enthusiasts it says buy CPUs priced under $500. If Ryzen 7 is successful, the stage is set for even more disruption in the mid-range and low-end segments as well. So, does Ryzen begin its life on stronger footing than Bulldozer? Let's find out.
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