It’s Computex this week, which means companies like AMD, Nvidia, and Intel will be demoing some of the systems and improvements they’ve got planned for the year. AMD’s Lisa Su is giving the keynote at Computex again this year, and the company is kicking things off by giving us a bit more detail on Zen 4 and its upcoming platform, Socket AM5.
First, to quickly recap what we know: Zen 4 is built on a 5nm process. It will arrive later this year along with Socket AM5. As befits the name, AM5 will introduce AMD’s support for PCI Express 5.0 and DDR5. Both of these technologies debuted on Intel’s Alder Lake last year, though compatible hardware has been nonexistent. That’s not unusual — PCIe 4.0 drives were in short supply for months after AMD debuted support for that platform — but it means both companies should have added support by the time that PCIe 5.0 hardware is practically in market.
The first part of AMD’s announcement reviewed the facts we already know on Zen 4 / Ryzen 7000, namely that it’s built on 5nm, arrives in a new LGA socket and will continue to use the chiplet strategy AMD debuted with Zen 2.
AMD is now officially confirming that Zen 4 offers a 1MB L2 cache and boost clocks of 5GHz+. The relevant footnote states that max boost clock on AMD chips is defined as the maximum frequency any single core can hit in a “bursty, single-threaded workload.” We reached out to ask AMD if we should expect any V-Cache chips under the Zen 4 banner and the company told us that while V-Cache is still an important part of its roadmap, it doesn’t have any announcements to make right now.
The I/O die is changing in a significant way with Zen 4. Ever since it launched Zen 2, AMD has built 7nm chiplets at TSMC and purchased its I/O dies from GlobalFoundries. Those dies were built on 14nm using 12nm design rules and they don’t seem to have changed much with the launch of Zen 3. With Zen 4, AMD’s I/O die will shift from 14nm to 6nm, move from GlobalFoundries to TSMC, and it’ll incorporate an RDNA2-based GPU for the first time. TSMC’s 6nm is an evolution of its 7nm, so AMD is maintaining a split between its I/O die and its chiplets.
Unless AMD chooses to sell some CPUs with disabled graphics similar to how Intel positions its KF line of processors, Zen 4 will be the first AMD CPU family to field a GPU core from top to bottom. We know that the graphics architecture will be based on RDNA2, but it’s not clear what kind of features or performance we should expect. Most desktop users don’t care much about the iGPU, but AMD has typically taken its onboard graphics more seriously than Intel, and DDR5 should be helpful to overall performance. Intel offers very little to compete with here, however, so it’s also possible that AMD will copy Chipzilla’s “less is more” strategy when it comes to desktop integrated graphics.
AM5, when it arrives, will provide CPUs with up to 170W of power, up significantly from the 140W maximum AMD targeted with AM4. While companies like AMD and Intel like to talk up improved compute efficiency with every generation, maximum socket power consumption continues to rise overall. While performance-per-watt has continued to improve in absolute terms, it has always been much easier for AMD, Intel, and Nvidia to improve performance by increasing power consumption, and AMD is doing that here as well.
Moving on to Socket LGA1718 / AM5 chipsets, we can expect three flavors in when the platform launches. All three will offer PCIe 5.0 support, but they distribute that support differently. Motherboards based on the X670E(xtreme) chipset will offer two PCIe 5.0 x16 physical connections and at least one M.2 slot with PCIe 5.0 support. X670 motherboards (without the “E”) will only have a single GPU slot with PCIe 5.0 support, but maintain the same promise of at least one NVMe PCIe 5.0 connection. Finally — if what you want is a storage server and you don’t care much about GPU bandwidth — the B650 platform gets you PCIe 5.0 NVMe storage, but GPU slots based on PCIe 4.0.
This is a smart move on AMD’s part. Video cards have always lagged behind maximum available PCIe bandwidth. It is not unusual for even the fastest first-gen launch GPUs with native support to show no benefit when tested on an older PCIe standard versus a newer one. That hasn’t changed since PCIe 1.0 first debuted and took over the job from AGP. PCIe 5.0 isn’t going to be exactly “necessary” for storage either, but SSDs will be able to take advantage of the higher bandwidth at launch while consumer single-GPU installations generally won’t.
AM5 will include up to four video ports on-motherboard with support for HDMI 2.1 and DisplayPort 2.0, SuperSpeed USB ports with up to 20Gbps signaling, and some boards with Wi-Fi 6E support. AMD has been making a major push into connectivity lately and we should see the fruits of that labor by the time this fall rolls around.