Early Power11 signals in the kernel

Date: 2024-02-22T09:00:00-08:00

Location: www.talospace.com

A number of people have alerted me to some new activity around Power11 in the Linux kernel, such as this commit and a PVR (processor version register) value of


. It should be pointed out that all this is very preliminary work and is likely related to simulation testing; we don't even know for certain what node size it's going to be. It almost certainly does not mean such a CPU is imminent, nor does this tell us when it is. Previous estimates had said 2024-5, but the smart money says no earlier than next calendar year and probably at the later end of that timeframe.

That said, the reputed pressures around Power10 that caused closed IP to be incorporated are hopefully no longer as acute for Power11, and off-the-books discussions I've had suggest IBM internally acknowledges its strategic mistake. That would be good news for Power11, but it's not exactly clear what this means for Solid Silicon and the S1 because S1's entire value proposition is being Power10 without the crap. While S1 will certainly come out before Power11, we still don't know when, and if there's a short window between S1 and a fully open Power11 then S1 could go like Osborne.

"Short" here will be defined in terms of how much work it takes to adapt the Power11 reference system. IBM understandably always likes to sell its launch systems first and exclusively before the chips and designs trickle down. The Talos II and to a lesser extent the Blackbird are a relatively straightforward rework of Romulus (POWER9's reference), so one would think adapting Power11 would similarly require little adjustment, though Romulus used the ASPEED BMC and any Raptor Power11 would undoubtedly use (Ant)arctic Tern/Solid Silicon's X1. In contrast, there'd be a bit more work to port Rainier (Power10) to S1 since the RAM would be direct-attach instead of OMI and there may be differences to account for with PCIe, plus the BMC change. The last estimate we had for the S1 machines was late 2024; putting this all together and assuming that date is at all accurate, such a system may have a year or two on the market before Power11 exits its IBM-exclusive phase.

That could still be worth it, but all of this could be better answered if we had a little more insight into S1 and its progress, and I've still got my feelers out to talk to the Solid Silicon folks. You'll see it here first when I get a bite.