Once upon a time, motherboard chipset updates were major news — mostly because we were impatiently waiting for circuit engineers to fix whatever they’d broken in the previous hardware release. There’s a lot less of that these days, happily, but the flip side of that equation is that motherboards don’t tend to evolve as quickly, either. A new PDF released by Biostar — probably before the company was supposed to and since removed — suggests that AMD’s upcoming X570 chipset will buck this trend by introducing support for several significant features.
According to Biostar, its upcoming Racing X570 GT8 will feature support for PCIe 4.0, with two full-size slots electrically configured for x16 and x8 operation, and a third full-size slot with an x4 configuration hanging off the southbridge. The three M.2 slots are described as being connected to the CPU and the southbridge, respectfully, using PCIe Gen 4 in all cases. Bandwidth is stated to be 32Gb/s, which corresponds with a PCIe 4.0 x4 link.
One thing to keep in mind, of course, is that SSD controllers will need to be updated to support PCIe Gen 4.0 themselves in order to take advantage of this bandwidth improvement. A PCIe 3.0 M.2 drive plugged into a PCIe 4.0 port will still work perfectly, but it won’t take advantage of the higher speed. One of the theoretical advantages of moving to PCIe 4.0, however, is that motherboard manufacturers can offer the same high performance as a current x4 PCIe 3.0 solution while using half the lanes. (PCIe 3.0 Gen 3 offers 985MB/s of throughput in each direction per lane, while PCIe 4.0 increases this to 1.969GB/s in each direction per lane).
Update: Biostar’s math doesn’t work as listed. 32Gbps is the x4 link bandwidth on PCIe 3.0, even though 4.0 support is listed.
Offering both DDR4-4000 support and three M.2 slots on a board are a touch surprising. AMD’s Ryzen 7 is not terribly fond of high RAM clocks, due to the need to run its Infinity Fabric at half RAM speed. This means that as you crank up the DRAM clock, the IF clock rises as well. There are rumors that AMD has implemented a new divider that would run Infinity Fabric at effectively 1/4 of the listed RAM clock (which works out to 1/2 the DRAM actual clock). In other words, instead of running at 2.5GHz using DDR4-5000, the Infinity Fabric would clock back down to 1.25GHz — if this rumor is true. Alternately, it’s possible that Biostar is simply advertising high memory frequency support without any corresponding improvements (as such) promised by AMD.
It would not be unprecedented for AMD to make a move like this. We haven’t had to deal with front side bus multipliers for a long time because motherboards no longer use FSBs, but some of you may recall when your AGP, PCI, and ISA clocks used multipliers and derived from the system FSB. The entire point of using multipliers was to ensure that these lower-clocked buses remained within their appropriate ranges. One reason why overclocking the FSB was considered superior to overclocking by multiplier (but also riskier) is that running the FSB at faster clocks also improved transfer rates over the ISA, PCI, and AGP buses, as well as the northbridge memory controller clock and associated RAM latencies.
But just because a motherboard advertises that it can support a given memory frequency doesn’t mean that CPUs will practically hit that frequency — and JEDEC has yet to publish a DDR4 standard above 3200MHz. We wouldn’t treat this information as proof of high RAM clock support for third-generation Ryzen just yet.
Separately, there’s one bit of unintentional humor on Page 7 of the PDF.
AMD and Intel will undoubtedly both be surprised to discover that the X570 chipset supports Intel Core and — somehow — the Intel B360 chipset. Interestingly, the X570 is the only new chipset on this list so far. Rumors have suggested AMD might have a B550 chipset refresh coming later this year, but for now it looks like only the X570 will ship for launch.