Zen’s development cycle is still in overdrive
AMD ups the pressure on Intel; Intel’s new top dog; Facebook to face the music; Microsoft tests ads; more….
AMD CERTAINLY has ambition, and a hectic release schedule. It was only last March that the first Zen chips appeared, and since then we’ve had a myriad variants, and a second iteration of the design, the Zen+. The EPYC range of server processors came along in June, and repeated the trick Ryzen had managed on the desktop: It offered a price to performance balance that left Intel more than a little bruised. EPYC sold well, taking a decent bite out of Intel’s Xeon market share, but there’s much more to be had. We are about to see EPYC 2, codename “Rome,” a 7nm server chip that is ready for sampling now, and due for commercial release this year.
EPYC 2 will be the first AMD chip to use the new Zen 2 architecture. This is a modular design, with 7nm process nodes, called “chiplets,” built around a 14nm I/O unit, rather than Zen’s more self-contained blocks. The architectural improvements include doubling the floating point width to 256-bit, and doubling the L3 cache, along with a slew of tweaks to branch prediction, bandwidths, prefetching, instruction cache, and more. Clock for clock, Zen 2 will be 10–15 percent faster than Zen+, minimum. The shrink also offers lower power consumption. Starting with a server chip shows where AMD’s plans lie, and where a good part of the profits are.
Moving to a 7nm process means more room for cores. The EPYC 2 will double the core count, now 64 rather than 32, instantly giving twice the power per socket. It also gets PCIe 4.0 support, and will be socket compatible with the previous EPYC, and indeed the next one, “Milan.” Performance? At AMD’s Next Horizon event, an EPYC 2 was pitted against a dual Xeon Platinum 8180M—no slouch with a total of 56 cores. The comparison employed the ray-tracing benchmark C-Ray, and the prototype EPYC 2 box coasted to victory. A carefully selected demonstration, of course; the benchmark likes floating point and lots of cores, which helps.
The desktop version of Zen 2, the 3000 series, is all set for this year. Leaks have it that the first chips are eight-core, run at 4GHz, and use the same AM4 socket as the 2000 series. There will be 12 and 16-core versions to follow. There’s also talk of a 32-core HEDT version. AMD’s multicore performance is already outstanding—Zen 2 will push it even further.
The next target is singlethread performance—AMD wants to top the desktop gaming benchmarks, a prize that has eluded it so far, but Zen 2 could be the architecture to do it. Clock speeds are unlikely to jump by much, but the efficiency improvements could tip it over, unless Intel does something…. With AMD’s blistering development cycle, Zen 3, an evolution of Zen 2, is promised in 2020. Zen 4, more of a
redesign, is already being planned. Radeon is also going 7nm. First to emerge will be Vegapowered Instinct M160 and M150 cards. These PCIe 4.0 cards are aimed at machine learning in data centers. The M150 is due any day, with the M160 following before spring. 7nm graphics cards will follow, but details are scant. More precise details on the upcoming Navi cards are thin on the ground, too, apart from rumors that Radeon is to focus on consoles and servers first. We’ve yet to know much about any response to Nvidia’s hardware ray-tracing Turing architecture either. A response is inevitable, but development teams are pretty busy right now, so it’ll be later rather than sooner.
AMD appears to have skipped the 10nm process; the original Zen was a 14nm piece, the Zen+ optimized and shrank this to 12nm. The new Zen 2 will jump straight to 7nm for its processing units. This must be galling for Intel, which is struggling to get its own 10nm process off the ground, and is reduced to getting all the value it can out of 14nm chips.
It’s only been 22 months since AMD got back in the game with the Zen-powered Ryzen, and the company has been firing on all cylinders ever since. EPYC 2 and its Zen 2 stablemates look set to increase the pressure on Intel across the marketplace, from servers down.
EPYC 2: the first chip to use the Zen 2 architecture