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.
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.
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.
ARM is a technology company that makes all of it's money licensing it's IP. If people don't use ARM chips, they don't make money.
Intel is a chip manufacturing company. They have their own CPUs, but they have also manufactured ARM CPUs (XScale) and licensed their IP for other chip manufacturers to use. I don't think Intel particularly cares what CPUs they make, as long as they make money.
So, in the grand scheme of things, Intel probably wouldn't care about making RISC-V CPUs if they could make money doing so, whereas RISC-V is a direct threat to ARM's business model.
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.
systemd is Roko's Basilisk.
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.
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.
I have been reliably informed by slashdot that architectural differences don't matter at all because of something called a translation layer.
For modern, high performance cores like the latest x86's you may be right. With their billions of transistors, large multi-layer caches, out-of-order execution, pulling instructions apart into u-ops (and/or multitude of other tricks employed under the hood), some extra complexity in instruction decoding could be a minor part of the transistor budget. Changing little in terms of raw performance, power efficiency etc and making the CISC vs. RISC debate a moot point.
But that's not what RISC-V is about. It's a clean-slate architecture.
It's meant to scale. For a big high performance x86 a complex instruction set may not matter much, but if you're scaling down into low-power / low cost / embedded cpu's, a simpler ISA means smaller, cheaper, more power efficient devices. For scaling up, RISC-V provides for modular extensions to the instruction set. Making applications easy to move from low-end to higher-end parts (and vice versa). Or if you're into some many-core design, having a smaller / simpler core to start with, means you can put more of them on your slab of silicon.
If virtualization is your thing, RISC-V architecture is designed from the start with that in mind. Not bolted onto a 20~30 year old architecture.
Not to mention there's no IP royalties due should you want to bake your own IC's. For large-volume / thin-margin items, that could be a biggie even if you're talking a few $cents a pop (or thereabouts).
Surely the above isn't all - check the RISC-V website if you haven't already. Given the number of organizations & companies behind, I think it's set to take over a large share in several markets. Probably in the long term though, from the low end up.
It must be awesome to be so good in your field that you get to call out your own companies FUD, without getting fired or blacklisted. I don't know if tech people will ever figure out how powerful their technology has made them.
But that's not what RISC-V is about. It's a clean-slate architecture.
It should be noted that RISC-V also has a complicated decoder. "Compressed instructions" is just a soft way of saying it.
The downfall of RISC was in part because is lacked a complicated enough decoder to allow a dense enough code stream to enable the instruction fetcher to pipeline multiple operations per cycle. The old limited pentium U and V pipes were enough to blow DEC's Alpha out of the water, let alone where x86/x64 is today retiring 4 or more operations per cycle on well optimized code.
The RISC idea is an extreme end of the spectrum. x86/x64 is not the other extreme. In this case optimality isnt found at the extremes.
"His name was James Damore."
Please attempt to develop English language abilities expected of a high school freshman before trying to be cute with things like "El Reg."
Really. This is absurd.
it's what they call themselves! and i lurnd inglish from bwainiac https://google.com/search?q=br..."i+can+do+science"
https://en.wikipedia.org/wiki/...
https://google.com/search?q="el+reg"
Hey guys, this is probably in rupees. So, 5-6 figure salary in dollars.
Still, hats off to the guy for turning down a large pay hike.
i couldn't put it in the main article, but i spoke to Madhu back in november, and it was USD $24 million. i still won't say who the company was but you can guess easily. and yes, turning down that much money is extremely brave. basically he realised that he could either be another PhD in amongst 100 other PhDs, or he could go back to his country and help his citizens reclaim sovereignty over their computing devices. when you're faced with that kind of decision it's not really a choice that you can walk away from with a clear conscience.
It should be noted that RISC-V also has a complicated decoder. "Compressed instructions" is just a soft way of saying it.
The complexity of the RVC decoder and the complexity of an x86-64 decoder are nowhere near the same.
The x86-64 can have instructions from anywhere from 1 to 15 bytes long, and it takes a lot of processing to determine how long an instruction is, especially with all the prefixes (like the REX prefix that sees so much use in 64 bit code for x86). This necessitates a state machine of some sort to parse the prefixes and apply their modification to the effect of the instruction in question. Each instruction is highly encoded, which requires a complex decoder to determine the length and operands, before the actual performance optimizations like register renaming begin. Additionally, each variable-length instruction may be split into multiple micro-ops. Intel makes highly performant processors despite, not because of, the instruction set.
Unless you have non-standard extensions, RISC-V instructions can either be 2 or 4 bytes (the 2 byte ones being the compressed instruction set). Instructions must be 2-byte aligned. It is trivial to calculate the length of any instruction in such a chip - if the least significant 2 bits are 11, it's a 4 byte instruction, otherwise it's a 2 byte instruction. In 4 byte instructions, the source and destination registers, and the highest bit of the signed immedate are always stored in the same place in the instruction word, allowing register renaming to execute in parallel, to a large extent, with actually decoding the opcode. The 2 byte instructions are not quite as clean, but still much simpler to decode than x86. (See page 70 of the RISC-V user-level ISA documentation.) Additionally, it seems that every 2 byte instruction is equivalent to executing a certain 4 byte instruction. (p. 81)
And yet, apparently RISC-V compressed is more concise than most variable-length encodings. (Including x86-64, IIRC. So much for "x86-64 uses memory bandwidth and cache more efficiently.")
Source for the RISC-V compressed instruction formats starts at page 67.
i couldn't put it in the main article, but i spoke to Madhu back in november, and it was USD $24 million.
Luke that number is preposterous. Brian Krzanich never even received that much. Also it is a little misleading to characterize GS. Madhusudan as "another PhD in amongst 100 other PhDs". He is the one of the leaders of India's homegrown semiconductor movement.
Luke could you provide sources for your claim that "some of ARM's criticism has merit?". The link provided is to your own mailing list post. I have been following RISC-V closely, and I'm curious what the "systemic failures" you describe there are.
i couldn't put it in the main article, but i spoke to Madhu back in november, and it was USD $24 million.
Luke that number is preposterous.
then that gives you some idea of how much of a threat A... err... the unnamed company that tried to bribe^Whire their engineers.
Brian Krzanich never even received that much.
Also it is a little misleading to characterize GS. Madhusudan as "another PhD in amongst 100 other PhDs". He is the one of the leaders of India's homegrown semiconductor movement.
my understanding was that it was neel who received the "offer", but i can't be sure. ahh.... yes it was. ohhh that's reeeallly interesting. fuckers who published the article REMOVED the bit about neel's "offer"... and "the author of the article no longer works with us". mmmm rrriiiight....
https://web.archive.org/web/20...
"Some of that open source zeal can be seen in the Shakti team here. Gala, who was offered a ‘good seven digit package’ by one of the big chip giants, decided against it. “This was an interview over a cup of coffee. The moment of realisation for me was sitting in the cafeteria, and seeing a hundred other PhDs there. The only distinction I had over them was Shakti. If I left it, I would just be another ball in the bag. So that’s why I didn’t leave,” he says."
What where they even thinking to launch a smear site like that? It's certain to backfire: the message such a site gives is that RISC-V is a serious challenger to ARM, if ARM has to go out and smear it, and people who've never even heard of RISC-V will now be checking it out because this kind of story gets picked up by the computing press and gives a huge amount of free publicity to RISC-V.
Oolite: Elite-like game. For Mac, Linux and Windows
RISC-V will probably never have performance even approaching x86. There is a lot to like about it, but you won't be seeing it used for high performance applications like games consoles or workstation CPUs.
The main reason is that the RISC concept itself turned out to offer much less flexibility for making optimizations on the CPU. A modern x86 CPU treats the x86 instructions as a kind of intermediate language that it dynamically translates into microcode operations on the fly, doing massive optimization in terms of concurrency and access to slow/contended resources like RAM.
With a RISC CPU the idea was to remove a lot of the opportunities for that kind of optimization, the belief being that such optimizations would be too complex for CPUs to do anyway and that the simpler architecture would scale better to higher clock speeds.
RISC-V does support out of order execution, but it's no-where near the complexity of what modern x86 does and the scope to reach that level just isn't there. On the other hand it's great for when you need energy efficiency or reduced complexity.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Nor is this the place to respond to trolls.
I object to power without constructive purpose. --Spock
Of all the buffoonary implicit to Trump his election most likely staved off a war with Russia. Most people have no idea how heated and sensitive the rhetoric had become, a lot of which was showing up in the election. Both the Democrats and Republicans were railing against Russia while the behind-the-scenes diplomatic situation deteriorated. It was as if they were trying to back Russia into a corner to prompt an action.
The US was pressuring Russia, pushing Putin's buttons, while exclaiming to the American public how evil and militant Russia is. All because they want Russia to back out of Crimea and Ukraine. Both the US and Russia are trying to influence the self-determination of the eastern European countries along with the EU.
I object to power without constructive purpose. --Spock
Am I the only one who actually read the archived web site and figured their talking points were pretty benign and reasonable? I mean, RISC-V isn't even a full spec at the moment and is still a work in progress.
Like most things I've come across in the open-source world, RISC-V is a bunch of good ideas, but ARM has proven, working implementations of their own ISA. From a business perspective, it's not outlandish to boast about that. If ARM were tearing apart the concepts behind RISC-V, then that would be a different story.
As The Register's analysis wasn't actually very thorough, let alone insightful, I'd suggest looking at the original criticism before letting loose the nerdrage.