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ARM: “RISC-V Architecture: Understand the Facts”

riscv-basics.com

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Re: ARM: “RISC-V Architecture: Understand the Facts”

#101

Post by Symmetry »

deepnotderp wrote: post #80
wlesieutre wrote: post #71

Earlier quoted context omitted.

It says right there "No announced RISC-V silicon is susceptible." Does someone actually make a RISC-V processor with out of order execution? Or is this a "They're going to make one eventually, so they'll have to address Spectre attacks before that happens" problem?

Yeah, no shit, because there's no major RISC-V silicon that's OoO. If you solely look at ARM cores that don't speculate, then ARM cores aren't vulnerable either. Also pretty sure BOOMv2 has been taped out: https://content.riscv.org/wp-content/uploads/2017/12/Wed0936...

Well, the A8 was vulnerable despite being in order but it was a mediocre design with an unusually long pipeline for a core of its class. Of course even in order core speculate a little based on predicting branches and their pipeline lengths but there's a very limited window for things to go wrong without going OoO and almost all in order cores can't execute enough dependent instructions to leak data without realizing they took the wrong branch.

Re: ARM: “RISC-V Architecture: Understand the Facts”

#102

Post by gruturo »

redshirt wrote: post #64
gruturo wrote: post #49

If this article is genuine (there are many comments arguing it might not be) I would consider it an excellent endorsement of RISC-V. If a company with an awesome engineering, like I consider ARM to be, is scared to the point of authoring some FUD, RISC-V has to be _really_ promising!

This is an utterly stupid move by ARM...if it's legit. Looks like it's a different domain registry than all the other ARM websites...not sure why, but that seems a bit fishy.

It might be the result of a PR firm doing something utterly inconsiderate and completely exceeding their mandate.

Re: ARM: “RISC-V Architecture: Understand the Facts”

#104

Post by ATsch »

snvzz wrote: post #60
Uberphallus wrote: post #47

A friend works in ARM and was extremely surprised (negatively) when I shared this link with him RISC-V may, perhaps, compete in two fields with ARM: education, where ARM doesn't give a fuck, and hacker boards, which is a tiny market compared to smartphones, smarttvs and so on. There have been around 15 million Raspberry Pi (the most popular SBC) sold in 6 years. Samsung sold 321 million smartphones last year alone. W…

>Whoever is thinking today about replacing some production anything with a RISC-V You're saying they're all wrong? https://riscv.org/membership/

well, there's a difference in supporting a technology and actually making chips with it. They are just investing in tech and research that might help them down the road.

I doubt any of those companies (aside from SiFive) will be actually using RiscV within the next few years.

Re: ARM: “RISC-V Architecture: Understand the Facts”

#105

Post by squarefoot »

pjmlp wrote: post #27
rwmj wrote: post #15

Earlier quoted context omitted.

As with all FUD campaigns, there's an element of truth. ARM does undoubtedly have a very large ecosystem and more features (RISC-V lacks hardware virtualization for example). But there are also loads of companies using and producing real RISC-V cores and all the major Linux distros are already shipping on RISC-V. The barrier to entry to RISC-V is far lower since you can quite literally download the cores off github a…

> As with Linux & Windows servers c.1999, who would you bet on winning in the end? It was more about UNIX & Windows. Linux won on the servers thanks to majority of UNIX guys cutting down costs by outsourcing their development costs into Linux. Had Linux not gotten the money of IBM, HP, Compaq, SGI, Intel, Oracle, Sun, Google, ...., the outcome would have looked much different.

"Had Linux not gotten the money of IBM, HP, Compaq, SGI, Intel, Oracle, Sun, Google, ...., the outcome would have looked much different."

Linux would win anyway. I've worked in the late 90s-early2k in places which were then already planning the move from proprietary Unix to Linux, some of them also in pretty critical contexts. Most of the companies you mention already had their own Unix: AIX, Digital Unix / Tru64, Irix, Solaris; they shoveled all that money into Linux (apparently against their own business) because they realized that selling products and services would pay in the long run a lot more than selling also the operating system, especially when the OSS competitor was gaining support every day. Soon or later that abundance in developers and testers would turn into less bugs, more features and faster response to vulnerabilities that no corporation in the world could equal.

Re: ARM: “RISC-V Architecture: Understand the Facts”

#106

Post by flurrything »

bmcusick wrote: post #91

Looking forward to "The Year of the RISC-V Desktop" articles. That's a joke, but I think Windows vs. Linux is the right reference frame here, assuming that RISC-V proves out. Those who want to roll their own and control their own destiny may go with RISC-V, while those who want a packaged solution will go ARM. And ARM will have to get better to compete. Western Digital has gone with RISC-V for a controller, because W…

Jokes aside. Since February you can already buy RISC-V SoCs that run Linux... at pretty high prices, e.g., https://www.crowdsupply.com/sifive/hifive-unleashed costs 1000$ bucks and the expansion board costs 2000$...

Still not practical for the masses, but not more expensive than similar extravagant architectures like PowerPCs (IIRC a PowerPC9 desktop system costs about 9000$ today).

Someone joked that you could get a 30$ xeon system on ebay from a couple of years ago that would crush these on pretty much any benchmark, but who knows, maybe some day riscv chips will become cheaper and more powerful. What we are seeing in the market today are the very first such systems, from the very first vendors.

Re: ARM: “RISC-V Architecture: Understand the Facts”

#108

Post by chithanh »

TomVDB wrote: post #100
delinka wrote: post #94

Earlier quoted context omitted.

Can you screenshot that and link to the screenshot? I don't see it marked as an ad.

I wish I did. It doesn't come up like that anymore.

Someone on reddit made a screenshot https://www.reddit.com/r/linux/comments/8xbqlv/arm_launches_... https://imgur.com/a/U2XGVee

Re: ARM: “RISC-V Architecture: Understand the Facts”

#109

Post by TomVDB »

chithanh wrote: post #108
TomVDB wrote: post #100

Earlier quoted context omitted.

I wish I did. It doesn't come up like that anymore.

Someone on reddit made a screenshot https://www.reddit.com/r/linux/comments/8xbqlv/arm_launches_... https://imgur.com/a/U2XGVee

Yes, I got the same one!

Re: ARM: “RISC-V Architecture: Understand the Facts”

#110

Post by deepnotderp »

Symmetry wrote: post #101
deepnotderp wrote: post #80

Earlier quoted context omitted.

Yeah, no shit, because there's no major RISC-V silicon that's OoO. If you solely look at ARM cores that don't speculate, then ARM cores aren't vulnerable either. Also pretty sure BOOMv2 has been taped out: https://content.riscv.org/wp-content/uploads/2017/12/Wed0936...

Well, the A8 was vulnerable despite being in order but it was a mediocre design with an unusually long pipeline for a core of its class. Of course even in order core speculate a little based on predicting branches and their pipeline lengths but there's a very limited window for things to go wrong without going OoO and almost all in order cores can't execute enough dependent instructions to leak data without realizing…

Yes, to be more precise, anything doing anything speculative with memory.
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