Showing posts from February, 2019

Ubuntu LTS 18.04.2 available

An updated release of the long-term support Ubuntu 18 (Bionic Beaver) is now available for ppc64el. Read the full changelog for 18.04.2. As with prior releases, Ubuntu 18 should "just work" on the Talos II. All Power ISA official releases of Ubuntu are Server branded and do not install a GUI by default.

The last POWER1 on Mars is dead

The Opportunity Rover, also known as the Mars Exploration Rover B (or MER-1), has finally been declared at end of mission today after 5,352 Mars solar days when NASA was not successfully able to re-establish contact. It had been apparently knocked off-line by a dust storm and was unable to restart either due to power loss or some other catastrophic failure. Originally intended for a 90 Mars solar day mission, its mission became almost 60 times longer than anticipated and it traveled nearly 30 miles on the surface in total. Spirit, or MER-2, its sister unit, had previously reached end of mission in 2010.

And why would we report that here? Because Opportunity and Spirit were both in fact powered by the POWER1, or more accurately a 20MHz BAE RAD6000, a radiation-hardened version of the original IBM RISC Single Chip CPU and the indirect ancestor of the PowerPC 601. There are a lot of POWER chips in space, both with the original RAD6000 and its successor the RAD750, a radiation-hardened version of the PowerPC G3.

That's not the end of Power ISA chips on Mars, though: Curiosity, which is running a pair of RAD750s (one main and one backup, plus two SPARC accessory CPUs), is still in operation at 2,319 Mars solar days and ticking. There is also the 2001 Mars Odyssey orbiter, which is still circling the planet with its own RAD6000 and is expected to have enough propellant to continue survey operations until 2025. Curiosity's design is likely to be reused for the Mars 2020 rover, meaning possibly even more Power chips will be exploring space and doing science where it counts millions of miles from home.


On a recent Hacker News discussion someone pointed me to this weird historical oddity: the AMD Opteron-socket-compatible POWER7 as reported in El Reg, circa 2006.

We use a POWER6 here at Floodgap for the main server, which as typical for RISC servers of those days uses a bespoke logic board and getting a replacement for it was quite expensive (as we found out when it blew one in 2014). Part of this was no doubt due to their low production volumes and in 2006 IBM was still producing x86 Xeon-based servers, so it made logical sense to try to consolidate their manufacturing. (Recall Apple did something similar with the Power Macintosh 4400 and the "Yellowknife"-derived "Gossamer" beige Power Macintosh G3, both of which were intended to use, or at least use more, off-the-shelf commodity PC components.)

What was particularly interesting about this concept, however, was that the envisioned AMD motherboard would also have accommodated SPARC processors, intended to attract IBM, Sun and Fujitsu at a time when Intel was planning to unify their own hardware for Xeon and Itanium (rip). In some respects it may have reflected an IBM perception that Itanium was potentially a threat to their RISC line and to achieve similar economies as Intel planned to.

Did this happen? Although the Register's article implies some prototyping was done, it doesn't look like it ever saw the light of day, and it's not clear why the agreement foundered. Indeed, the POWER7 systems I've all seen continued to use a custom board and I've never heard anything about SPARCs of that generation using such a common logic board either. In particular, the lowest level Power 720 820x machines — the ones that would have been most likely to use such a cost-reduced design — are in fact very similar to the POWER6 820x machines (including our local 8203-E4A), and there are even upgrade paths.

The idea didn't really die, though, because IBM finally opened up their architecture into OpenPOWER with the POWER8 and now anyone can make a board that a Power chip can go into. And, of course, one particular vendor's POWER9 workstation is what this very article is being typed on. Naturally this wasn't altruism on Big Blue's part; it was their attempt to build a larger multi-front ecosystem to combat x86 dominance in the server room, which would embiggen the pie for "big RISC" servers and thus IBM's slice of it. If it also caused Power chips to turn up in other environments, well, that would be more icing on the cake. While the "Opteron POWER7" looks like it never happened, and no one's putting Epyc chips in Talos IIs, at least some concept of a cross-vendor Power logic board did manage to survive and we OpenPOWER pioneers are the lucky beneficiaries today.

So long, Itanium

I have mixed feelings about Intel announcing the end of Itanic the Itanium. Everyone knew this was coming, of course, but Intel finally officially gave Itanium a death date of mid-2021 instead of keeping it limping along as it has for the past several years.

On the one hand, I don't like Itanium for killing PA-RISC. The first machine I ever had root on was a HP K250 running HP-UX 10.20, and I still have a PA-RISC laptop (an RDI PrecisionBook C160L) and a C8000 with dual PA-8900s, the most powerful Precision Architecture workstation HP ever made. I thought PA-RISC was a nice, clean instruction set with decent performance and HP seemed to at least try to keep up with PowerPC and SPARC, and I think it died before its time (there was even talk of using PA-RISC in Amiga computers!). HP is still the Itanium's only customer, mostly because they would probably roil the remnant HP-UX user base with another architecture switch. In fairness, it should be noted that it was HP themselves that didn't think there was any money in continuing with developing their own CPU (the same logic they applied to killing the DEC Alpha, another exceptional architecture murdered way too early), and that may have been true at the time, but Itanium has painted the Superdomes into a corner and HP-UX and OpenVMS will probably go the way of emulation like the Unisys mainframes have gone.

On the other hand, the end of IA-64 marks the end of an era, not only for non-x86 designs within Intel, but as the last major VLIW CPU (which Intel and HP called "EPIC"). GPUs are of course largely VLIW, VLIW chips still turn up in embedded systems applications and there are still oddballs like the Russian Elbrus, but as a CPU architecture load/store designs have largely won. Even your typical Intel chip is essentially a modern RISC-style core with an x86_64 instruction decoder bolted on (and of course all that other black box crap that you don't get with POWER9). Itanium made it worse with a pretty weaksauce x86 emulator and its unusual architecture choices that make it relatively resistant to Spectre-style attacks but difficult to optimize typical software applications for, a recurrent problem with VLIW compilers in general. This was one of the big reasons the SGI IA-64 workstations never really took off compared to the MIPS systems they replaced.

Big classic proprietary CPUs were a big part of my early career and losing Itanium is a sad whimper. But while Power ISA is a much less adventurous design, it's a much more performant one, and OpenPOWER means it will stay relevant for a long time to come. If you've got a Talos II under your desktop as I do, you chose right.