ARM's Own Employees Complain About Anti-RISCV Website (theregister.co.uk)

lkcl writes: Phoronix and The Register have an insightful look into an effort by ARM that is reminiscent of Microsoft's "Get The Facts" campaign. RISC-V's design is a revamp of the RISC concept that is intended from the ground up to fix the mistakes and learn from the lessons of the past 30 years. Power efficiency is 40% better than ARM or Intel. Compressed instructions reduce I-cache misses by 20-25%, which is roughly comparable to the same performance that would be achieved by doubling the Instruction Cache size. Yet despite El Reg's insightful analysis,
all is not as it seems: on further investigation, some of ARM's criticism has merit, whilst some of it is clear out-and-out FUD from ARM that, being so critically dependent on free software, had its own employees complain so much that the site was pulled.

Also we cannot help but wonder which "Big Chip" company offered seven-figure salaries to try to shut down the IIT Madras Shakti Project. Most interesting however is the fact that ARM -- a $40 billion dollar company -- is rattled by RISC-V enough to use underhanded tactics, whilst Intel on the other hand is actually investing.

Comments

Of course they are rattled

[Anonymous Coward]

They reality is that there has been very little innovation in the area of computer architecture in the past couple of years.
Only thing they have been doing is adding more cores.
Once you have a completely open CPU design that fabs can freely fabricate as much as they want, it will eat up a huge slice of the embedded extremely low power market.

Re:Of course they are rattled

[alvinrod]

I wouldn't say that. Companies like NVidia are doing a lot of work in designing cores that are made for deep learning and other types of specialty workflows where a general purpose CPU isn't as efficient or the amount of processing power needed is massive. Others like AMD have developed new interconnect technologies (they call it Infinity Fabric) that can be used to connect multiple small dies together on an interposer. This has massive ramifications as it means you can create massive dies in a much more cost-effective manner. We've also seen both Intel and AMD making moves towards APUs and with HBM (high bandwidth memory) it's eventually going to hit a point where x86 processors can become a SoC to that point that PCs become much more simplified. Maybe this doesn't have the wow-factor of some flashy new invention, but steady progress is often far more important than most of what people want to call "true" innovation.

RISC-V is also an ISA (instruction set architecture) which is not an actual chip implementation. It's very similar to ARM in that it allows for companies to develop their own implementations of the chip, much like how Apple, Samsung, NVidia, and Qualcomm all make their own cores. The only difference is that RISC-V doesn't cost anything to license. You'll still need to pay chip designers to create an implementation if you don't have an open implementation that's free to use and there's no guarantee that any free implementation fits the use case that you'd want to target. Even if it does, there's still no guarantee that someone's proprietary implementation doesn't have such significantly better performance that it's better just to pay the additional cost anyway.

This summary is a mess

[wonkey_monkey]

I don't think I've ever read a more confusing summary. Clarifying that RISC-V isn't ARM's baby would have been a start. The subject of each sentence is also hard to decipher - is The Register's (do we have to call it "El Reg"? That's so twee) analysis about RISC-V, or about ARM's anti-RISC-V site? And so on.

My Thoughts

[DaMattster]

ARM is scared of losing it's death grip over IoT and smartphones. Usually active FUD campaigns bely this real concern. One day ARM will have to come to grips with the fact that it will be toppled. ARM is about to repeat the same expensive mistakes that Microsoft did with its Get The Facts campaign.

Of course Intel is investing

[Anonymous Coward]

All this time they've been living from the x86 architecture. Their last significant architecture change was Sandybridge, concocted in Israel rather than Intel headquarters. Now they have Spectre and Meltdown and AMD is running circles around them with Ryzen. They killed off Alpha by hooking HP on Itanium and then killing off Itanium. MIPS died from a culture of binary distribution/compatibility (simulating non-interlocking 3-stage pipelines with half-interlocking 7-stage pipelines is just absurd). ARM is not exactly new. Everybody is moving to the cloud and tablets and app stores where putting up new ecosystems on different architectures is comparatively easy and Microsoft is running Windows proper into a corner where everybody wants alternatives.

If there is any time for changing horses, it is now.

Re:Intel

[Logger]

I call hogwash on the claim that RISC-V is significantly more power efficient than ARM or Intel. I could not find the summary's claim of "Power efficiency is 40% better than ARM or Intel. " anywhere in the referenced material.

I'm guessing he's misquoting this line "instruction cache access alone dissipated 40% of the energy in a five-stage RISC pipeline."
Unless someone has come up with a RISC-V implementation that completely eliminates 100% of i-cache access power, in no way can you interpret that to mean RISC-V is 40% more power efficient than ARM or Intel. The paper does claim "[RISC- V compressed programs] fetch 25% fewer instruction bits than RISC- V programs", but that's comparing 2 different RISC-V ISAs; not RISC-V to ARM or Intel.

I don't know enough about RISC-V to really say if it's ISA is inherently more or less power efficient than ARM or Intel. I'd be surprised if it wasn't better than Intel, and there's certainly room for improvement over ARM, but the only way to be that much better is *magic*.

The real reason ARM is scared of RISC-V isn't some theoretical efficiency advantage that has never been proven out, but the free licensing structure. There's a lot of IOT designs out there that just need a good enough processor. There's also high volume embedded processor applications whose roadmaps don't don't foresee the need for continual processor improvements, so they'd rather not keep paying per CPU royalties to ARM when they don't care about future enhancements. In those markets cost is king, and it's hard to compete with free.

Interestingly, the embedded markets I'm talking about don't use JIT. JIT based solutions require more memory, aka more cost. JIT based systems also have longer boot times, which is undesirable in these applications. Think, storage controller.

The biggest JIT ARM users are actually in the smartphone space, and near term that space has other sticky reasons to stay with ARM. Compiler support ( really only the apps are JIT, everything else is C), debuggers, and lot's of other ARM IP that is bundled with the ARM license. That other ARM IP is not something most people outside of SoC ASIC design are familiar with. So giving up ARM is to give up a whole lot more than just the ARM processor, and isn't so easily replaced.

I could imagine China encouraging Chinese companies to build a complete ecosystem around RISC-V, that could compete in the smartphone space though. That would align well with China's strategic goals, and probably scares the bejesus out of ARM. And if that is beginning to happen, I don't see how ARM could actually stop it. Really, they only can try to delay it.