Intel's 11th Generation Rocket Lake-S CPUs are perhaps the most eagerly awaited hardware launch of this half of 2021 for both fans of their products and those less kindly disposed. A large part of that is the incorporation of a new core architecture - the first major revision since Skylake - and consequently are seen as Chipzilla's first significant response to AMD's Zen 3 Ryzen 5000-series CPUs. It's a lot of weight for any product to have on its proverbial shoulders, but with launch still a few weeks out some of the enthusiasm may already be draining out of the market.

We have known for almost a year now that motherboards based on the Z490 chipset would be forwards compatible to Rocket Lake-S desktop CPUs. The same memory (DDR4) and socket (LGA1200) standards are in use down the range, and so the assumption of many was that Intel would extend compatibility to more affordable chipsets too. Bringing Rocket Lake-S to B460 and H410 would significantly reduce upgrade costs and widen the ecosystem suitable for slot-in upgrades. This release schedule just happened to have a snag however.

As outlined in a support post uncovered this week, Intel have stated that Rocket Lake-S compatibility among 400-series motherboards will be limited to designs based on Z490 and H470 chipsets (BIOS updates permitting). Both the B460 and H410 chipsets will be left without an official upgrade path, despite being LGA1200 designs.



While the support document doesn't delve into the reasons for this exclusion, Hardware Zone Israel has been able to tease out the apparent rationale, as well as some notable exceptions. The snag has been traced to the PCH integrated into the B460 and H410 chipset, which is unable to connect to the CPU though two new sideband channels operating alongside DMI that are necessary on Rocket Lake-S.

It has been speculated that the use of this less capable PCH is rooted in past 14nm production constraints, necessitating an older 22nm alternative design. Z490 and H470, as higher margin designs intended to support Rocket Lake-S going forward, could justify the production allocation and cost where B460 could not.

A few manufacturers apparently have B460 motherboards that will offer Rocket Lake-S support via BIOS updates. Launched a little into the chipsets lifespan, they have incorporated the 14nm PCH necessary for upcoming CPU support. In GIGABYTE's case they are denoted by a V2 suffix, but compatibility shouldn't be assumed until the manufacturers confirm it. The news isn't great for anyone who opted for B460 as an affordable upgrade path either way.

Rocket Lake-S CPUs for desktop should be arriving next month. 500-series motherboards compatible with both 10th Gen and the upcoming 11th Gen CPUs are already available to preorder.

SOURCE: HWZone Israel (Hewbrew), Intel 11th Gen BIOS Update Support Documentation