Minor point: ARM-1-based devices were kinda, sorta, brought to market around '85-'86. That's neck-and-neck with MIPS I. Real ARM-2 based machines in '87 were three years ahead of the RS/6000.
Of course, lots of people were developing RISC architectures in the early 80s, in parallel.
Which makes articles like this one: http://www.digitaltrends.com/computing/intel-arm-processors-... ridiculous.
"the unthinkable happened. Intel revealed it was going to build ARM processors."
Do your damn research, people :-)
I have always wondered how ARM succeeded when MIPS was already around. Anyone know ?
In a way it is reminiscent of the z80 clones that was all over the place in the 80s.
So I am very sensitive to the misuse of "RISC trade mark".
Ideal RISC design is very easy to develop. It can be easily tailored to various application domains, including high-performance (OoO) and low-energy. RISC instruction semantics should be simple, all implementation details are hidden. In my opinion, there are only three RISC designs - DEC Alpha, IBM Power and RISC-V. Others contain various design issues that show their inner cogs and that had to be accounted in the designs different from the original one.
(in my MIPS implementation experience I've implemented 33% of MIPS commands in the first month and spent another month accounting for branch delay slot)
ARM contains three deviations from ideal RISC: user-visible PC (read of PC returns PC of command+8!), multi-cycle group load/store commands and condition codes. All three "features" make it difficult to design something different in performance than original ARM.
Is that pedentry better than the "android isn't really open source because Google doesn't do pull requests" though?
Citation needed. Different from Anand's mentioning of "custom designed implementation of ARM ISA" on his webpage without any proof and further copied and taken to Wikipedia. One non-verified source cannot be trusted, sorry. Of course the chip is a custom design ( as it mentioned @ Wikipedia ), because ARM generally do not provide the peripherals and you can "bolt" whatever you like. Apple may be a big company, but they definitely lack the skill set to do such large chips themselves. The wild rumor goes to their attempt to ditch BRCM for wifi's chips for ages, something that would have happened if they had the resources to design something themselves. Not to mention the huge chunk of chip on the new macbook 12", rumored to be from the acquisition of Anobit, which if you have some knowledge of design is at least 4 generations behind. That of course is a speculation, much like Anand's quote of "custom ISA implementation" from A8 and onward, but at least the nm process can be seen to be quite old.
> One non-verified source cannot be trusted, sorry.
I don't work for Apple, and if I did I would value my job more over satisfying your need for a citation. But anyway, since I cannot prove or disprove that Apple did design their own chip, which they did, I will point out that NVidia, a much smaller company, has managed to do just what I claimed, see: https://en.wikipedia.org/wiki/Project_Denver
> Apple may be a big company, but they definitely lack the skill set to do such large chips themselves.
Really? I think their purchase of a processor design company in 2008 speaks to the fact that they do have this talent in house: https://en.wikipedia.org/wiki/P.A._Semi
PA Semi designed their own POWER CPU, which they developed from scratch. Don't tell me these people (who work for Apple now) don't have the capabilities and resources to design a processor which can implement the ARM ISA.
Either provide a citation that proves that Apple hasn't designed their own core implementing the ARM ISA, or stop demanding some from my claim, which has a lot more evidence behind it.
The fact that they have dual sourced CPUs from TSMC and Samsung, which are on different processor nodes, thus requiring a different layout and mask, tells me that Apple's hardware engineers absolutely know what they're doing, and can design the internals of a chip:
http://www.anandtech.com/show/9686/the-apple-iphone-6s-and-i...
Plus, around the time of the PA Semi acquisition, news outlets reported that the engineers were working on a custom CPU for Apple devices: http://appleinsider.com/articles/08/09/15/apples_pa_semi_wor...
I honestly don't know why I put so much time into refuting this. Many other people on the internet think that Apple is designing their own core inside the iPhone, how else would a dual core chip smoking the living shit out of Samsung and Qualcomm's quad and octo core processors?
Here, have another person who says Apple design it themselves. http://apple.slashdot.org/comments.pl?sid=8083459&cid=506143...
That's correct: the spin-off from Acorn was part of the deal with Apple (done by John Sculley).
However, ARM had three investors: Acorn, Apple and chip company VLSI Technology Inc (VTI).
Apple did. It's been widely acknowledged that the processor inside the iPhone is a custom design which implements the ARMv8 ISA. See: https://en.wikipedia.org/wiki/Apple_A9
> Furber and his co-designer, Sophie Wilson, had found research from the Berkeley campus of the University of California into a new type of processor: one that simplified the set of instructions it would follow, in order to enable a sleeker, more efficient design. This style of processing was called “reduced instruction set computing”, or Risc, and the Berkeley Risc designs had been put together by just two people, David Patterson and Carlo Sequin.
ARM were hardly the first people to bring a RISC CPU to market: MIPS, SPARC, and POWER are RISC architectures which pre-dated ARM.
> By 2007, Intel had abandoned the excesses of the company’s Pentium line
Pentium is a brand name, which still exists today. What the author is referring to is Intel's "NetBurst" architecture.
> powering the servers at companies like PayPal.
Citation needed. The CEO of X-Gene said PayPal has “has deployed and validated” services based on their CPU, but readily admits to having shipped only 10,000 units, which is just peanuts to datacentre guys. Source: http://www.theregister.co.uk/2015/04/29/aookied_micro_q4_201...
Overall, I'm happy for ARM's continued success, and I hope that they and the rest of the semiconductor industry will continue to innovate and bring the performance per watt up.
That being said, this Guardian article is crap. It's factually incorrect in places, missing sources for claims, and generally doesn't do anything to actually explain why people supposedly don't know who ARM is.
tl;dr - Some guys in Cambridge, who are fab-less, made a CPU from a RISC design. They license the designs to partners who can add whatever they want around the CPU (or redesign the CPU as long as they conform to the instruction set, as Apple does). The reason they're "not well known" is because they don't sell CPUs themselves, companies like Apple, Qualcomm, MediaTek, etc do.