Tech —

Ryzen 5 review: AMD muscles in on Intel’s i5 sweet spot

Gaming performance still an anomaly, but the Ryzen 5 1600X and 1500X are great chips.

Ryzen 5 review: AMD muscles in on Intel’s i5 sweet spot
Mark Walton

"It can't just be that we're the cheaper solution," said AMD in 2015, back when Ryzen was little more than a handful of hopeful slides in a press deck. But as AMD and the wider tech press knew, competing with Intel on performance as well as price was always going to be an uphill battle. The Bulldozer architecture was a bust, and Intel had cornered the market on high-end desktop and server CPUs. If you were at all interested in media creation, or gaming with a discrete GPU, Intel was the best option.

Then came a trickle of tech specs. Ryzen would be an eight-core, 16-thread chip. It would be a dramatic rethinking of AMD's CPU architecture. It would boost instructions-per-clock by an unthinkable 40 percent over Bulldozer (ultimately, as the Ryzen reviews rolled in, the actual IPC gains were as high as 52 percent). There was a hope, perhaps a naive one, that after months of riding the hype train, AMD would do the extraordinary and not only catch up with Intel, it might even beat it.

The reality proved more complex. Ryzen 7, the range which comprises AMD's top-end 8C/16T chips, was an absolute number-crunching monster in multithreaded tasks—much to the delight of content creators stuck paying Intel's absurd prices for Extreme Edition and highly clocked Xeon chips. But raw IPC remained just shy of Broadwell-E, and some way behind the mainstream Kaby Lake architecture. More importantly, gaming performance was oddly mixed. Ramped up to 4K, Ryzen largely holds its own against Intel. Dropped down to 1440p or 1080p, frame rates—including those all-important 99th percentile minimums—lag behind.

Two months later—after a handful of OS tweaks, BIOS revisions, and patches that show just what can and can't be done to boost Ryzen's performance via software—little has changed. Ryzen, which now spans the range from high-end eight-core chips through to mid-range six- and quad-core chips in Ryzen 5, remains a remarkably powerful CPU in some tasks, and a curiously humdrum one in others. It's an architecture that, like Intel's Broadwell-E, doesn't command outright recommendation, but instead a more measured endorsement.

That's especially true of Ryzen 5, here tested in its 6C/12T 1600X (~£240) and 4C/8T 1500X (£175) forms, which directly compete with Intel's mainstream Core i5 chips. For roughly the same price as a 4C/4T Core i5 7600K (~£230) or 7400 (£170), Ryzen 5 offers two extra cores or double the threads and full overclocking support. Ryzen still isn't for everyone—the sheer gaming grunt of Intel's chips makes sure of that. But, for the first time in a long time, AMD has a compelling alternative.

Six cores or four?

The Ryzen 5 range is made up of four chips. At the top is the £240/$250 Ryzen 5 1600X, a 95W six-core chip that boasts simultaneous multithreading (SMT, the equivalent of hyper-threading), 16MB of L3 cache, and a 3.6GHz base clock. By default, the 1600X will boost to 3.7GHz across all cores, 4.0GHz across two cores, and—with a suitably robust cooling setup—up to 4.1GHz on a single core via AMD's XFR (extended frequency range) functionality. Intel's i5-7600K with its four cores, lack of hyper-threading, and meagre 6MB of shared cache, looks feeble by comparison.

Specs at a glance AMD Ryzen 7 1800X AMD Ryzen 7 1700X AMD Ryzen 7 1700 AMD Ryzen 5 1600X AMD Ryzen 5 1600 AMD Ryzen 5 1500X AMD Ryzen 5 1400
Architecture Zen Zen Zen Zen Zen Zen Zen
Cores/Threads 8/16 8/16 8/16 6/12 6/12 4/8 4/8
Base Clock 3.6GHz 3.4GHz 3.0GHz 3.6GHz 3.2GHz 3.5GHz 3.2GHz
Max Boost Clock 4.0GHz 3.8GHz 3.7GHz 4.0GHz 3.6GHz 3.7GHz 3.4GHz
XFR Boost 100MHz 100MHz 50MHz 100MHz 50MHz 200MHz 50MHz
L3 Cache 16MB 16MB 16MB 16MB 16MB 16MB 8MB
Process 14nm 14nm 14nm 14nm 14nm 14nm 14nm
TDP 95W 95W 65W 95W 65W 65W 65W
Price $500/£430 $400/£350 $330/£320 $250/£240 $219/£200 $175/£175  $169/£160

The same is true of the i5-7400, which comes in at roughly the same price as the £175/$189, 65W 1500X. Where the 1500X boasts 16MB of L3 cache, hyper-threading, and full overclocking support alongside its 3.5GHz base clock and maximum 3.9GHz boost clock, the i5-7400 features just four cores, 6MB of cache, and no overclocking support. The other two Ryzen 5 chips—the £200/$219 6C/12T Ryzen 5 1600, and £160/$169 4C/8T Ryzen 5 1400—also boast impressive specs compared to the similarly priced Intel equivalent, although sadly neither were available for this review.

The Ryzen platform is suitably robust too. Unlike the now defunct AM3 platform, the AM4 platform has all the modern features you'd expect, including support for DDR4 memory, PCIe X4 storage, and USB 3.1 Gen 2. The high-end X370 chipset features support for overclocking (all Ryzen chips are unlocked) as well as SLI and Crossfire. The cheaper B350 chipset sheds a few PCIe lanes and SLI and Crossfire support, but still allows for overclocking. There's even a full-spec line of overclocking-friendly micro-ATX and mini-ITX motherboards in the form of the X300 series. Those haven't yet been released, but are expected soon.

Certain retail Ryzen chips come packed with one of AMD's new air coolers.
Enlarge / Certain retail Ryzen chips come packed with one of AMD's new air coolers.
Mark Walton
The larger Wraith cooler on the left is rated for a TDP of 140W.
Enlarge / The larger Wraith cooler on the left is rated for a TDP of 140W.
Mark Walton

Ryzen brings AMD up to parity with Intel, which is a remarkable achievement given just how far it had fallen with Bulldozer. The under-the-hood architectural improvements—which you can read all about here—are smart, favouring efficiency over unchecked performance. And while AMD's slightly hopeful TDP measurements mean that its 95W chip still pulls as much power under load as Intel's 140W chip, it's a vast improvement.

Like with Ryzen 7, though, Ryzen 5's headline specs aren't always indicative of real-world performance. Intel's Kaby Lake architecture, and to a lesser extent Broadwell-E, maintain a sizeable lead in raw IPC. For the applications that prefer raw singlethreaded performance, Ryzen loses out. There are other issues too. Ryzen has proven more sensitive to memory bandwidth than Kaby Lake, but at launch many motherboards in the enthusiast X370 range wouldn't boot at higher memory speeds. Subsequent BIOS updates have largely fixed this issue, but benchmarks show the memory controller itself remains a weak point.

Just as irksome is overclocking, which is an all-or-nothing deal: you either run Ryzen at the maximum clock speed you can reach at all times, or you opt for Ryzen's ability to automatically adjust the clock speed by small 25MHz increments and save power. There's no in-between. Even if you do opt to overclock, the ceiling using typical air coolers or all-in-one liquid coolers is much lower than with Kaby Lake and Broadwell-E. Where an 8-core Broadwell-E chip can reach 4.5GHz without issue, Ryzen tops out at around 4.1GHz across the board, even in its six- and quad-core forms.

That's disappointing, but not entirely unexpected. Ryzen 5 is the same chip as Ryzen 7, but with disabled cores. Ryzen is designed around a pair of four-core core complexes (CCX) linked together via AMD's "Infinity Fabric" interconnect. In the 1600X and 1600, one core from each of those CCX is disabled. In the 1500X and 1400, two cores from each CCX is disabled. Many were hoping that the quad-core chip would forgo Infinity Fabric, and instead run four physical cores from a single CCX. That would, in theory, negate any possible performance issues that arise from Infinity Fabric, which is dependent on memory speed and clock speed.

AM4 specs at a glance X370 B350 A320 X300 A300
PCIe Gen 3 Graphics 1x16/2x8 1x16 1x16 1x16/2x8 1x16
USB 3.1 Gen 2 2 2 1 0 0
USB 3.1 Gen 1 10 6 6 4 4
USB 2.0 6 6 6 0 0
SATA/NVMe 6/2 4/2 4/2 2/2 2/2
SATA Express 2 2 2 1 1
PCIe Lanes x8 Gen 2 x8 Gen 2 x4 Gen 2 x4 Gen 3 x4 Gen 3
Overclocking Y Y N Y N

Regardless, it does mean that the company is trying to maintain parity between chips by ensuring there are always two CCXes actively connected by Infinity Fabric. AMD was also forced to issue a Ryzen-optimised power-profile to prevent Windows from prematurely parking individual cores to save power (the new profile offloads power management directly to the CPU), while also dealing with performance issues related to SMT, similar to how Intel's hyper-threading suffered problems at launch.

These are classic early adopter issues—and more may emerge as others are fixed. But while Ryzen clearly needed more development time before being rushed to market—a sentiment shared by at least one motherboard manufacturer—it's now stable enough to recommend as a daily driver.

Channel Ars Technica