Past that, NVIDIA’s newly announced Ada Lovelace architecture GeForce RTX 40 series video cards do not support PCIe 5.0. The first generation of PCIe 5.0-enabled consumer SSDs are expected to land a bit later this year, and they should be able to hit sequential burst transfer rates above the limits of PCIe 4.0 (~7GB/sec). ![]() So while AM5 can support PCIe 5.0 throughout, the reality is that we’re still going to see a lot of PCIe 4.0 in use even in higher-end motherboards.Īs for the necessity of PCIe 5.0 overall, thus far AMD is primarily focused on what it means for NVMe drive speeds. A very well-designed motherboard is required with impeccable traces, and on top of that the overall short throw of PCIe 5.0 means that retimers/redrivers become necessary rather quickly. Compared to PCIe 4.0, 5.0 has much tighter signal integrity requirements (the signaling frequency has been doubled), which at least at this time, makes PCIe 5.0 expensive to implement. While AMD has baked in 5.0 support into the Raphael CPUs, it’s up to motherboard vendors to actually make it so. Which with the addition of PCIe 5.0 support to the platform, is going to be a recurring theme. Of note there, the current chipsets only use PCIe 4.0 connectivity to the Ryzen CPU, so the current generation of chipsets will not be making full use of the bandwidth capabilities of the CPU itself. We’ll go more into the specifics of the chipsets in a bit, but lays out what is wired to the CPU, and what will need to be wired to the chipset. To visualize this, we’ll use part of the AM5 chipset diagram. So there is no native SATA support on the CPU, and supplying that will come from the chipset. Whereas AM4 CPUs could drive a mix of NVMe and SATA drives (up to 2 SATA + a PCIe x2 for NVMe), AM5 is purely PCIe. There has been one regression, however, and that is SATA support. As a result, AM5 CPUs can drive a total of 3 Superspeed Type-C ports, a fourth Superspeed Type-A port, and then the aforementioned USB 2 port. The USB 2 port is new for this generation, and meanwhile 3 of those USB 3 ports now also support the USB Type-C connector, unlike AM4 which could only natively drive Type-A ports. Meanwhile, the updated socket also offers enough pins for the CPU to drive 4 Superspeed USB 3.x ports, and a USB 2 port. Past that, things look a lot like AM4, with 16 PCIe lanes to directly drive one or more PCIe slots, and then 4 lanes for hooking up the chipset. In practice, those additional lanes are intended for NVMe drives, giving AM5 a second x4 connection to drive a second NVMe drive though we have seen some motherboard designs where vendors are stealing the second x4 for a PCIe 5.0 x4 slot. Which gives the chip a maximum cumulative PCIe bandwidth of 112GB/sec in each direction. More significantly still, PCIe 5.0 is now supported (at least on the Ryzen 7000 “Raphael” processors), doubling the bandwidth of all of those PCIe lanes to a max of 4GB/sec/lane. The biggest change here is that the AM5 socket now provides for 28 lanes of PCIe, a net gain of 4 lanes. ![]() So for AM5, AMD has increased the amount of I/O and the flexibility offered with the platform. While AM4 already supported a fair bit of I/O, including 24 PCIe lanes, 3 displays, and 4 Superspeed USB ports, there was still room for improvement. We'll split this piece up into four parts that cover the four major components of the Ryzen 7000 launch: 1) the Zen 4 CPU core, 2) the on-chip I/O die that supports the CPU's non-CPU features and handles internal connectivity, 3) the 600-series chipsets that handle most external connectivity, and 4) the physical AM5 socket that will outlive all of the other components by a few years.More I/O For AM5: PCIe 5, Additional PCIe Lanes, & More DisplaysĪMD’s other big expenditure using socket AM5’s additional pins is on I/O support. This one will focus on all the other changes, including the ones that will be with us long after Ryzen 7000 is old news. ![]() One is a look at the actual chips' performance and power efficiency, located here. So we're publishing two Ryzen pieces today. The last time this many things changed at once was back in 2017, when the first-generation Ryzen chips originally launched. The processor architecture is changing, but it's also being accompanied by changes to everything from the chipset to the physical socket that the chips plug into. ![]() Further Reading Ryzen 7600X and 7950X review: Zen 4 starts off expensive but impressiveĪMD's Ryzen 7000 launch is bigger than just the processors.
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