Friday, May 31st 2024
AMD Shuffles Feature-sets of its 800-series Chipset, X870 is B650E Successor
AMD is debuting its Ryzen 9000 series "Granite Ridge" desktop processors powered by the "Zen 5" microarchitecture later this year. These chips are compatible with existing AMD 600-series chipset motherboards with a simple UEFI firmware update, but the company is also taking the opportunity to launch the AMD 800-series chipset family alongside these chips. The lineup will be led by the AMD X870E, followed by the X870. These two chipsets should launch immediately alongside the new processors, but will later be joined by the AMD B850 and B840. There's no entry-level chipset planned, the AMD A620 will continue to hold the fort for AMD here. There is an interesting new mix of product differentiation, according to a leaked GIGABYTE slide scored by VideoCardz.
If you recall, the X670E and X670 were differentiated by a lack of Gen 5 PCI-Express x16 PEG slots on the X670, which instead was limited to Gen 4 on the PEG slot. The X670 still had Gen 5 NVMe slots attached to the CPU, and had practically the same I/O features as the X670E, including the same counts of downstream PCIe Gen 4 general purpose lanes. Both the X670E and X670 are 2-chip solutions, in that the second chip is a connected to the general purpose PCIe lanes of the first chip, which in turn is connected to the processor. Things are going to change with the 800-series. The top-spec X870E will be a 2-chip solution, with PCIe Gen 4 general purpose lane counts resembling the X670E; but the X870 is a single-chip solution that more closely resembles the B650E in I/O. The X870 (non-E) now gives you Gen 5 PCI-Express x16 PEG, just like the X870E and the B650E, and at least one Gen 5 x4 NVMe slot attached to the CPU, but has fewer downstream Gen 4 general purpose PCIe lanes than the X670. Both the X870E and X870 assure USB4 connectivity, and support CPU overclocking. Things get very interesting in the mid-range.
The AMD B850 is very similar to the X870 in terms of downstream general purpose PCIe Gen 4 lanes. What's more, it even assures a Gen 5 x16 PEG slot, much like the X870. Where it differs from the X870 is its CPU-attached NVMe slots. Gen 5 is made optional here (motherboard vendors can provide Gen 5 if they want, but are perfectly free to offer Gen 4 instead). Unlike the X870E and X870, the B850 doesn't mandate USB4 connectivity, however, motherboard vendors will be free to offer discrete USB4 controllers on their boards. Much like the B650 and its predecessors dating all the way back to the B350, the B850 supports CPU overclocking.
The B840 is a new introduction with this generation, there's no real predecessor to it, although it closely resembles the A620A, which in turn resembles the B550. It completely removes all forms of Gen 5 PCIe from the platform—the x16 slots are limited to Gen 4, as are the M.2 NVMe slots attached to the CPU. This chipset also lacks CPU overclocking support. It does retain memory overclocking, and B840 motherboards should support AMD EXPO, as well as manual memory overclocking. What sets the B840 apart from the A620 is its Gen 4 PCIe connectivity both along the PEG and general purpose PCIe.
Source:
VideoCardz
If you recall, the X670E and X670 were differentiated by a lack of Gen 5 PCI-Express x16 PEG slots on the X670, which instead was limited to Gen 4 on the PEG slot. The X670 still had Gen 5 NVMe slots attached to the CPU, and had practically the same I/O features as the X670E, including the same counts of downstream PCIe Gen 4 general purpose lanes. Both the X670E and X670 are 2-chip solutions, in that the second chip is a connected to the general purpose PCIe lanes of the first chip, which in turn is connected to the processor. Things are going to change with the 800-series. The top-spec X870E will be a 2-chip solution, with PCIe Gen 4 general purpose lane counts resembling the X670E; but the X870 is a single-chip solution that more closely resembles the B650E in I/O. The X870 (non-E) now gives you Gen 5 PCI-Express x16 PEG, just like the X870E and the B650E, and at least one Gen 5 x4 NVMe slot attached to the CPU, but has fewer downstream Gen 4 general purpose PCIe lanes than the X670. Both the X870E and X870 assure USB4 connectivity, and support CPU overclocking. Things get very interesting in the mid-range.
The B840 is a new introduction with this generation, there's no real predecessor to it, although it closely resembles the A620A, which in turn resembles the B550. It completely removes all forms of Gen 5 PCIe from the platform—the x16 slots are limited to Gen 4, as are the M.2 NVMe slots attached to the CPU. This chipset also lacks CPU overclocking support. It does retain memory overclocking, and B840 motherboards should support AMD EXPO, as well as manual memory overclocking. What sets the B840 apart from the A620 is its Gen 4 PCIe connectivity both along the PEG and general purpose PCIe.
74 Comments on AMD Shuffles Feature-sets of its 800-series Chipset, X870 is B650E Successor
You know, I spent a month meeting with companies that were developing USB4 hardware and doing research before I wrote the USB4 article, I didn't just pull some shit off the internet, even if it's from the USB-IF, since you clearly didn't understand what you read.
A bigger issue for AMD might be wafer allocation. The chipset would have to be made at 7nm/6nm in order to not overheat. AMD need lots of 7nm and 6nm wafers for several other chiplettes, so a completely new Promontory will have to wait some more.
Even more such traces would be needed for Gen5 chipset, plus more retimers.It's not an issue as Gen5 chipset will not be introduced for a few good years. It's just not needed by anyone. Desktop platforms have even struggled to make any meaningful use of Gen5 lanes on CPU since late 2021... Hardly a few enthusiasts use Gen5 SSDs, and those giant heat sinks are monstrocities. Only by the end of this year new GPUs will start using Gen5 lanes, 3 years after their introduction on motherboards. Lack of technology syncing there.
There will be even less reasons to introduce Gen5 chipset link any time soon, as the increase in PCIe lanes is driven predominantly by CPU. It's enough if a new platform adds another one or two Gen5 x4 link and by 2030 we will have at least 32 Gen5 lanes from CPU alone. Plenty. Modern chipset simply needs to remain cheap enough as to not drive motherboard prices too much and reasonably connected to southern components, mostly USB, SATA and other smaller PCIe devices.
I will add more. X670E gave us up to 7 M2 support and we don't really need any more than that but USB 4. So I might purchase some faster RAM to bring me up from 5200 MT/s.
videocardz.com/newz/amd-introduces-x870e-chipset-promises-am5-updates-through-2027
Probably not helped by the fact that many B650 non-E boards had no PCIe 5.0 at all, despite specification otherwise.
First time I've seen a reference to a Promontory 19 chipset. I thought A620 was a cut-down Promontory 21. Maybe that's what the cut-down version is called?
What's the deal with that first image in the article, though? That diagram had so much compression artifact that it almost look AI-generated - or maybe scrambled, by someone who really shouldn't be taking that screenshot, off what looked like a remote desktop interface from the watermarks. ;)
The fact that the ASM4242 is two years late is hardly AMD's fault, as it got stuck in certification hell at the USB-IF due to a certain company that "donated" the specs to the USB-IF didn't explain how a lot of things worked, but assumed that anyone who was going to make a USB4 host controller knew how that company did things internally.
The ASM4242 was always supposed to be connected directly to the CPU this way. This info leaked way before the AM5 platform launched.
Obviously, the host still must provide more than 10 Gbps in order for USB tunnelling to take place. And that's the whole point of bare minimum requirement of 20 Gbps for the host. Practically, every host has 40 Gbps speed due to Microsoft requirements for PCIe data from x4 PHY.
2.2 USB4 Fabric Architecture
The USB4 Fabric is designed to meet the needs of multiple transport protocols. Its main features are:
Signaling rates that support high throughput interconnects :
- 10 Gbps (for Gen 2), 20 Gbps (for Gen 3), and 40 Gbps (for Gen 4).
A620 can be either a cut-down Promontory 21 chip (allowing Prom21 chips with defects to still be sold), or a Promontory 22 chip (which is smaller and cheaper to manufacture).
Leaves me quite hopeful we might see a PROM21 (or PROM22) AM4 board since, clearly there's no 'restrictions' between platforms. It's just PCI-E linking the 'chipset' to the SoC, after all.
[I *really* want to see a 'new' AM4 board, if only for all the salt it will mine from the "AM4 is ded" crowd]
USB4 at 10 Gbps is only a mode name of USB4 Gen 2x1, and not "USB 3.1 Gen 2", despite the same speed over one lane.
Both names signify the same speed only, but are coded differently on the electrical layer.
Hence, USB 3.1 Gen2 neither belongs to USB4 specification nor to USB4 product line.
Market name for any product supporting the name 'USB 3.1 Gen2' is SS USB 10 Gbps.
That's why your initial post was dismissed, but you kept going...Now you are learning finally about USB4.
USB4 spec does support a single link at 10 Gbps, but there is no market name for a USB4 device that would do only USB data at 10 Gbps. Such device or port is called 'SS USB 3.2 Gen 2x1' (old name USB 3.1 Gen2), with logo 'SS 10'. Therefore, "USB4 10 Gbps" device or port do not exist, only a mode of operation within wider data envelope.
Minimal market name for USB4 device or port is 'USB4 20 Gbps', with a logo 'encircled 20'. This is USB4 Gen 2x2. Such device supports both 10 Gbps per single lane and 20 Gbps in total per dual lane, in both directions. And here we are coming to "USB4 10 Gbps" situation whereby USB4 data could operate over one lane while other data, such as PCIe or DP operate over the other lane. If you, however, connect 'SS 10' peripheral, such as flash drive into USB4 host port, the port will not operate as USB4 port, but as USB 3.2 Gen 2x1 port due to different data coding protocol. Therefore, once again, USB4 could NOT mean "just USB 3.1 Gen 2 (10 Gbps)". It never meant that, and it will never do.