OpenPOWER Foundation – Open-Source / Open Hardware PowerPC CPU ISA

44 45 1 year ago

"By open sourcing and developing on the POWER ISA - one of the most sophisticated processor architectures available - the OpenPOWER Foundation is democratizing access and extending the reach of the RISC-based architecture.'

Open for All

With more than 350 members collaborating regularly, the entire semiconductor industry - from global organizations with deep expertise to individual creators with a new lens - can innovate with choice and build and develop across the full Hardware and Software stack."

https://en.wikipedia.org/wiki/Power_ISA

https://en.wikipedia.org/wiki/Power10

https://www.itjungle.com/2024/12/02/power11-takes-memory-ban...

ThinkBeat• 1 year ago

According to Raptor the newest generation of POWER chips contain a big binary proprietary blob.

Would these pose a problem for the this foundation?

net01• 1 year ago

link ?

p_l• 1 year ago

No - essentially a modern CPU is composed of multiple blocks, not just the actual CPU core. Some of those IP blocks will be closed source, often from third party vendors, and sometimes that means proprietary software blobs to interact with them (whether because the documentation to configure them is proprietary, or because you need to load proprietary microcode or firmware).

The OpenPOWER foundation does not deal with entire CPU module / SoC component, and as such it's not really in their bailwick.

The issue with POWER 10 cpus was that at least two important blocks without which the CPUs are essentially useless involved such third party components that required closed source firmware blobs to initialize.

One of them was effectively the only OMI<->DDR4 (iirc) memory interface (OMI - serial link for memory, successor of POWER8/9 Centaur link), and the other was I think Synopsys' PCI-Express Root Ports

ladyanita22• 1 year ago

Why the focus on Risc-V when the Power architecture already has high-performance cores? Genuine questions.

bhouston4• 1 year ago

Power and RISC-V are going after different markets.

While Power is IRSC has a lot of legacy baggage that makes it significantly more complex that RISC-V (which is clean slate and purposely simplified.) It is also definitely not optimized for low power situations / embedded.

It is basically super computer chip.

Also unlike ARM and RISC-V it isn't designed to be extensible/customized by users. It is more monolithic.

cduzz• 1 year ago

I wouldn't say "super computer" chip (or at least "supercomputer")...

I've read the definition of a supercomputer as "some computer that takes specific domain, compute-bound problems and turns them into IO bound problems." (Implicitly, in that statement is the second statement of "and they have a ton of IO too). They're not really general purpose computers, and likely you'd be able to use risc-v or anything else, with specialized hardware, as the basis of a "supercomputer".

The power platform, on the other-hand (I'll create a new word here) is a foundation for a "SuperEnterprise(tm)" computer.

Power has insane / awesome things like "oh, you can use the ECC bits for ECC and hardware memory tagging[1]." Eventually such things may trickle down to things like ARM or RISC-V, but they're pioneered at the top of the enterprise mountain and trickle down...

[1]https://www.devever.net/~hl/ppcas

Symmetry2• 1 year ago

If you're a student in a microarchitecture class who has to implement a core in a semester then the simplicity of RISC-V makes it a much better choice. And if you're a grad student trying to try out some idea in your thesis then you should also choose RISC-V for the same reason.

If you're creating a microcontroller for a specific product then RISC-V's ability to only implement the hardware features you need is a big benefit and its compressed instructions let you save money using fewer RAM chips.

lizknope3• 1 year ago

The people I know using RISC-V don't want a high performance core. They want a very small area low power core for things like PCIE and DDR link training.

panick21_6• 1 year ago

OpenPOWER was created to sell chips more then anything else. But many people don't just want some stanard 'high performance' chip. There are many different kinds of high-performance chip. A high-performance chip, for a car, a gaming computer, a AI chip or a cloud chip that runs VM are all different.

There is simply not that amount of options in the POWER market. Its a restrictive set of vendors.

Pretty much every new startup designing high performance chips picked RISC-V. And they optimize their chips for specific use-cases.

In addition, the software ecosystem for RISC-V is arguable already better then POWER. And many companies and universities are working together on making it first class. Android is going to RISC-V, it will never be on POWER.

So if you were to design something for consumers, not going with RISC-V would be crazy.

RISC-V is also evolving far more quickly. There are like 80 working groups working on improvements all in the open. The amount of companies working on POWER is tiny in comparison.

mixmastamyk• 1 year ago

Didn't that Android port to R5 get partially walked back?

jamesy0ung• 1 year ago

What exactly is the selling point of the Power ISA? Why would I want to use it over RISC-V?

Symmetry2• 1 year ago

You can accomplish the same task in substantially fewer instructions, leading to higher performance for a given level of design effort.

Also a more developed software ecosystem.

snvzz6• 1 year ago

You can accomplish the same task in substantially fewer instructions, leading to higher performance for a given level of design effort.

The statement is true and favorable to RISC-V, as it is the one with lowest instruction count and code size; RISC-V wins, and it is not even close.

Also a more developed software ecosystem.

Historically true, but right now the momentum is with RISC-V, and it is absolutely is catching up, and no longer a point of contention.

e.g. Debian is the largest Linux distribution by its library of packaged software. There, RISC-V has already overtaken[0] it in available package count.

0. https://buildd.debian.org/stats/graph-week-big.png

bhouston4• 1 year ago

It is aimed at a completely different market from RISC-V.

RISC-V advantages is that it is an incredible simple and extensible architecture aimed at low power / embedded use cases. It is also easy to customize (similar to ARM) for specific use cases.

Power ISA is a super computer chip, while RISC-like, has a lot of legacy baggage and isn't designed for low-power nor is it designed for embedded situations. It also is not designed for customizability, it is more like a monolith project.

Power ISA will have space at the top of the market for very high performance CPUs. But I think it will be stuck there as there are no benefits over RISC-V in the areas where RISC-V is growing right now.

orbifold• 1 year ago

That isn’t actually true. I‘ve personally worked on an embedded POWER processor https://github.com/electronicvisions/nux. It is used as a dual core embedded micro-controller in a neuromorphic chip. Each core has just 16kB of memory on chip and 4kB instruction cache. POWER has subsets of the instruction set which have a gcc and llvm target and are well suited for embedded use cases.

Main advantage of RISCV at this point is that it has a larger community. But at the time it didn’t even have a vector instruction set, whereas we could easily modify the POWER one for our purposes.

panick21_6• 1 year ago

RISC-V is absolutely not and never has been 'aimed at low power / embedded'. Literally from the very beginning the target was 'be an ISA for everything'. Its just natural that simpler things were standardized first and came to market first.

That POWER is better at top of the market is highly questionable, every new startup coming into the high performance space has universally picked RISC-V over OpenPOWER.

Also, nowadays even complex ISA were fine for embedded. The cost difference for stuff like that is tiny. Its really just about how many options do you have in the market, both open and closed. And that's where RISC-V by now simply has more.

OpenPOWER was only fake open for a long time, while marketing itself as open. Only when they were totally getting crushed, did they update and are more like RISC-V, but it was many years to late.

snvzz6• 1 year ago

It is aimed at a completely different market from RISC-V.

Not possible. RISC-V is aimed at absolutely everything.

Thus leaving no sizable niche exclusive to POWER ISA.

irusensei• 1 year ago

I feel like regardless of what you can accomplish with it will be drowned by having to deal with IBM's brilliant handling of their products.

The only occasions I interacted with POWER was in projects where the client was happily deploying bog standard enterprise amd64 servers running Linux to replace it.

phendrenad2• 1 year ago

So what exactly does OpenPOWER grant me? If I create a CPU core design that implements the same ISA as, say, the PowerPC G5 chip used in Macs from 2002-2012, can I sell it? Or can I open-source it? Or is OpenPOWER incompatible with the PowerPC line?

panick21_6• 1 year ago

PowerPC and POWER are not the same. PowerPC was created because Apple allied with IBM, but they wanted Motorola as a supplier. So they basically changed Motorola own RISC chip into something POWER like.

OpenPOWER used to be restricted, but because RISC-V absolutely crush the OpenPOWER fake marketing with being really open, OpenPOWER (like MIPS) after a few years have changed and are now more like RISC-V.

MisterTea4• 1 year ago

No, The AIM alliance's goal was to create a standard Power architecture: https://en.wikipedia.org/wiki/AIM_alliance

PPC Mac is the same PPC that Motorola developed and marketed. The key difference lies in the platform as Power PC is just a CPU ISA, it does not define a platform which includes hardware layout and booting. So you cant just buy a Motorola chip and boot MacOS because MacOS expects a Power Macintosh complete with Power Macintosh hardware and firmware.

Arm and Risc-V also do not define a platform. IBM is the one who developed a standard hardware and firmware design, the BIOS, for the Intel 8086 and thus the PC was born. The PC platform is why we think of computers as general purpose machine that boot any OS. Outside of that ecosystem it's a big mess. Arm and Risc-v do not define platforms which is not a good situation.

sillywalk• 1 year ago

PowerPC and POWER are not the same.

AIUI PowerPC is essentially an extended (original) POWER.

The AIM alliance defined PowerPC which had 32bit and 64 bit modes, and IBM also added ISA extensions - the PowerPC AS or "Amazon" - for its AS/400 line.

When the POWER3 came around, the original 32Bit POWER ISA was deprecated, but still included for backwards compatibility. So all POWER chips since then implement the PowerPC ISA.

snvzz6• 1 year ago

The community behind POWER has long been overtaken by RISC-V.

This can easily be seen reflected in Debian (largest distribution by package collection), where RISC-V has recently overtaken[0] ppc64 as the third largest ISA in available software.

The expectation is that RISC-V will continue to climb and eventually overtake ARM and x86.

RISC-V is inevitable.

0. https://buildd.debian.org/stats/graph-week-big.png

OpenPOWER Foundation – Open-Source / Open Hardware PowerPC CPU ISA

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