AMD first teased its upcoming Ryzen 7000-series CPUs and its new Zen 4 CPU architecture at CES in January. The company said that the chips would use the new AM5 CPU socket, that they would be built on a 5 nm manufacturing process from TSMC, and that they would be available this fall.
None of those facts has changed, and AMD still hasn’t announced pricing or more specific availability info for the new chips. But at its Computex keynote this week, AMD revealed a few additional details about the Ryzen 7000 processors and the motherboards and chipsets that will support them when they’re all released to the public in the next few months.
Zen 4’s foundation: Socket AM5
Before covering any specific features of Zen 4, Ryzen 7000, or AMD’s 600-series chipsets, we should cover some basic facts about the upcoming AM5 CPU socket.
Socket AM4 has been remarkably long-lived. AMD hasn’t always been the best at communicating which AM4 motherboards could support which AM4 processors, but as of this writing, most motherboards going all the way back to 2017 can support new Zen 3 processors like the Ryzen 7 5800X3D. That’s a remarkable run for any socket, but it’s especially impressive given that Intel introduces a new socket (or compatibility-breaking updates for an existing socket) roughly every two years or so.
It also means the AM5 socket is a big leap forward, regardless of the chipset it’s paired with. It’s AMD’s first consumer land-grid array (LGA) CPU socket, which means that (like Intel’s, and like the sockets for AMD’s Threadripper chips) the 1,718 small copper pins are in the socket on the motherboard rather than on the bottom of the processor. Its maximum power limit has been boosted to 170 W, compared to AM4’s 142 W, opening the door to higher core-count CPUs that can run faster for longer. AM5 also adds support for PCI Express 5.0 (though the exact support you get will depend on your chipset and possibly your CPU), and it requires an upgrade to DDR5 RAM.
That DDR5 RAM upgrade is one downside for AM5 and Ryzen 7000 compared to 12th-gen Alder Lake CPUs, at least in the short term. Alder Lake-compatible motherboards come in both DDR5 and DDR4 versions, letting buyers choose whether they want the (mostly marginal, but not nonexistent) performance benefits of DDR5, or if they prefer to reuse an existing DDR4 kit. DDR4 is also much cheaper and easier to find than DDR5 right now, though this will gradually change as support becomes more widespread and memory manufacturers boost DDR5 production to meet demand.
Socket AM5 will also support quad-channel DDR5 memory for motherboards with enough RAM slots. In the past, most consumer and enthusiast PCs have topped out at dual-channel memory, while quad-channel RAM has been reserved for higher-end workstation and server CPUs. All of AMD’s Zen architectures have been more sensitive to memory bandwidth increases than Intel’s chips, whether you’re talking about integrated graphics performance or general CPU performance. But doubling the theoretical memory bandwidth doesn’t usually double your real-world performance—we’ll need to wait for more tests and benchmarks to see whether quad-channel memory support is worth the extra cost.
AMD notes that despite all of AM5’s upgrades, the actual size and shape of the CPU package have been kept the same. This was done intentionally to ensure that CPU coolers designed for AM4 chips would continue to work with AM5 chips. Intel’s LGA 1700 socket has a taller, more rectangular shape than its previous sockets, which can (but doesn’t always) break CPU cooler compatibility based on where the bottom of the CPU cooler makes contact with the processor.
Connectivity for AM5 motherboards will depend on the chipset you’re using and the exact motherboard you buy. But AMD says that AM5 motherboards will be able to provide up to 24 lanes of PCIe 5.0 bandwidth, a total of 14 20Gbps USB 3.2 Gen 2×2 ports, and up to four HDMI 2.1 or DisplayPort 2.0 ports for driving displays using an integrated GPU.
https://arstechnica.com/?p=1855701