Arm vs RISC V- What You Need to Know

hey there my name is gary sims and this is gary explains now one of the big debates that's been in computing over the last few decades is cisc versus risk and i have a video about that here on this channel and in the past i've compared for example arm which is risk to x86 i've compared to risk 5 to x86 and this video i want to look at risk versus risk as in risk 5 versus arm what are the differences between these two architectures well if you want to find out more please let me explain [Music] before we get started i want to point out that because i have covered some of the history of arm and some of the stuff about risk five in two previous videos that i will leave a time code down in the description if you want to jump over some of these bits however i have been updating the slides as i've been doing those other videos with stuff that i think is also important so let's get cracking straight away what can we find out here quick history of arm acorn computers was a british computer company establishing cambridge and army cities in cambridge today in 1978 and it was most famous for building the bbc micro which was a really really important micro for the home computer revolution that happened in the uk during the 80s elite which was a classic absolute classic game was written and developed by david braban and ian bell on the uh bbc micro and it was originally published by acorn soft so it's acorn companies it comes off for the bbc micro and of course it was ported to so many others because you've got modern versions of elite elite frontiers now 1983 acorn started its acorn risk machine arm project and resulting in a reduced instruction set risk processor that would eventually be known as the 32-bit arm one now to keep costs low the arm one used plastic packaging so the design had to be under one watt and the prototype chip was made in 1985 and when they test it this is the story that is told at the time by the people involved the first test board had a fault on it and the chip was actually only powered via leakage so it wasn't even connected properly to the uh to the power supply and so that was designed to run at one what the chip actually averaged only a hundred milliwatts because even through this leakage it was actually being powered up so they'd worked out they'd made found out this way to build a very power efficient chip and then of course from then onwards you've then got the progression of the different chips arm two came out in 1987 and the first consumer computer based on an arm chip so we're talking about apple max today with the m1 way back in 1987 you had the acorn archimedes which had an arm processor and that was a desktop pc now by the time we get to 1986 our apple began using arm processors for its r d and eventually it came up with the first tablet that our apple did and it was called the newton an amazing machine at its time however didn't succeed so that project died but the use of that arm processor was revolutionary at the time and so a advanced risk machines rather than acorn risk machines arm is spun off from acorn in 1991 with investment from apple and of course this is 1991 and here we are all these years later because apple's still very much a big user of arm processors now at this point it became an iep company intellectual property so rather than selling actual physical chips or making physical chips it sold the design of those to other companies who could then put them in their chips now by 2002 arms partners had shipped over one billion arm-based chips that number reached 50 billion by 2014 and now in 2021 an average of six billion chips are shipped every quarter so that's absolutely amazing and of course arm chips today are found in smartphones both in android and ios tablets laptops and of course servers so basically everywhere now a few things that i've added in here compared to previous videos because i want to just talk about uh these because we will be comparing the arm iso to the risk 5 iso so first of all we have to point out the arms isa is mature and advanced okay risk five started uh kind of in 2010 where of course here we were talking about things that started way back in the 1980s and onwards and so that by now the arm isa is very mature very stable and advanced so we're talking about things like cryptography extensions memory tagging extensions modern things to do with security and making sure that the your malware can't run and access different parts of the memory that shouldn't do and the result of that in this process of maturing the architecture we're now to the v9 architecture so version nine of the architecture and the cortex a510 the a710 the x2 the neoverse n2 are all uh v9 processors so it's not v9 it's not some sort of vaporware it's here today in actual processors and some of the big things that we find in v9 are scalable vector extensions version two now arm originally partnered with fujitsu to create uh the scalable vector extensions it's at the heart of the world's fastest supercomputer and now sve 2 a development that enables better ml and adds dsp like capabilities now the point is here is that the vector extensions are variable which means if you have you can write the software once it doesn't matter how those vector extensions are implemented in the hardware at 64 bit wide or 128 bit or 256 bit wide the same software will work that's the key thing about the scalable vector extensions and the other big thing is we've got the arm confidential compute architecture cca which in practical terms we're talking about a thing called realms which basically allows you to run mini little hypervisors inside of the chip so that your banking app uh can't get access by anybody other part of the operating system or any other apps in its own private hardware protected memory and it's obviously way more uh complex than that in the sense it can do much more but that's basically where we're getting at and because of that it's also useful not only in smartphones but also in cloud computing because now we're coming to an area where you can actually guarantee that whatever service that you're running on your cloud computer is isolated completely from all the other services running on that cloud computer of course cloud computers run lots and lots of things that's the whole point of them that they're running so many different tasks but now you can actually have them isolated so that's a really interesting thing that we're going to look forward to in the next few years now a couple of other things worth mentioning is first of all is for cortex a processors 32 bits is dead and that basically means the processes we find in android smartphones so from 2023 all arm cortex a cores will be 64-bit only in fact iphone processors have already gone to 64-bit only so that's arm compatible processors designed by apple have already gone 64 bits only and i have a whole video called 32 bits is dead where i look at what that means in the history and what it means in terms of compatibility if you're interested in finding out more but it's important this is for cortex a processors and why i say that is because arm actually makes four types of process cortex a four smartphones tablets laptops and so on but it also has of course a very powerful micro controller range in the cortex m range okay and these still remain at 32 bits and the cortex m0 plus which is the smallest microcontroller they do is just 12 000 gates 34 32 bit processor 12 000 gates 0.04 millimeters squared so a very very tiny microprocessor you can get on there it also has cortex-r processors which are for real-time applications and then there are the neoverse processors which are for servers so you've got the neoverse n1 the n2 and the v1 let's do the same thing for risk five so the original risk one processor was the result of some research done by david patterson a very important person in the risk and risk five community he wrote the original paper on risk while he was at the university of california berkeley and that is uh he coined the term risk idea simple instructions fixed length opcodes load store architecture we'll talk more about that in a minute released in 1981 had 44 000 transistors and implemented 31 instructions that was followed then by the risk 2 processor in 1983 and that had a condensed 16-bit instructions so you can get more instructions in a certain space of memory and then there is the risk 4 and the risk 5 processors don't get talked about much but basically they were designed by students who were in patterson's under patterson supervision 1984 1988 one was optimized to run small talk that was optimized to run lisp so we've got risk one risk two risk three and risk four which is then why we then get into risk five so the work on risk five started in 2010 again at the university of california it's an open icer okay that means that the the architecture is free to use by anybody you don't need a specific license or to pay any royalties however it's not open source hardware this is a big thing that people don't understand and i will go into that a bit more in a moment there are two versions 32-bit and 64-bit versions and 128 is possible according to the architecture documentation every risk five processor has to instead to implement the base integer iso okay and if it's a 32 bit one it becomes rv risk five thirty two i for integer or risk five sixty four bit now that base integer doesn't even have multiply and divide commands and it's a very very simple base uh uh iso that needs to be installed and then there are extensions for adding on other things including multiplier and divide now a risk five is made by commercial and non-commercial organizations so for example there are universities that are designing risk five processes they're publishing their work they're using it as a tool to teach their students about how to design processors and there are also commercial entities for example sci-5 which has been in the news recently with the possible approach by intel to buy it and that's commercial operation and its licensing model is similar to arms in the sense if you want to use their risk fire processor core then you pay a licensing fee whether that's a royalty or whatever it is the business deal they have but it's a commercial organization that charges money for the designs of the risk five processes that it creates now we talked about those extensions so for example if you wanted uh multiplication division you have to implement the m extension if you want atomic instructions you have to implement the a extension then there's also single double and quad precision floating point f d and q and there's also an extension for using compressed instructions so again being able to squeeze more instructions into a certain amount of memory now it could get quite boring because most process will probably implement uh integer multiplication and division most will probably implement some form of floating point operation so g is a short form for m a f d so if you have a risk 5 64 gc that means the g means it's got m a f and d it's got multiply and it's got the floating point and c means it's also got the extension for compressed instructions and there are other non-ratified extensions like b for bit manipulation p for practice mds v for vector operations and so on and these will be ratified probably over time at the moment they become a proposal and then if someone wants to implement them they are of course free to do that now talking again about this thing about open iso and not open source hardware this is directly from the risk 5 faq if a company builds a risk 5 implementation is it required to release the source code for that core no the source code can be completely closed and this is because of course it's just the fact that you can build a processor that follows that instruction set that when it sees those ones and zeros what do those ones and zeros mean that's what risk five gives you it doesn't give you free cpus it doesn't give you free chips and it's not like the linux revolution but for hardware it's completely different and one of the reasons it isn't software with software you just need to be a person with a compiler and internet connection and you can start contributing to open source software it's not hard but building chips of course is a multi-million dollar business so you know if you want a chip run you don't just ring up and say oh please send me three chips you have to you know it's a huge complicated business so there's nowhere the same dynamic as open source software not only that of course is the risk five iso needs to be stable it's not meant to be changing every five seconds with this patch and that patch and this patch and that patch he actually wants to be something pretty stable now the chips are designed well whoever designs them that's up to them what they do but trying to do collaborative chip design has not been something that has really been uh done really before unlike collaborative software which is done very successfully now of course you have fpgas they do help but they're not going to help when you're trying to make a competitor to the latest uh snapdragon processor or the latest you know the apple m1 processor in risk five that's not going to help that's a very complicated advanced technical thing that you're trying to do so this is not a linux like revolution for hardware and i wish people would stop saying that so let's get on to the differences so first of all arm is a company and an architecture okay so when people say it's using the r market like the apple processors use the arm architecture the uh that super computer from fujitsu uses the arm architecture but army is also a company that designs processors that design cpu cores that are compliant with its own architecture so it is a company and an architect whereas risk five is just an architecture governed by an organization risque international so they govern the architecture but they're not in the business of designing chips themselves they're in the business of uh maintaining and overseeing the architecture so arm designs cpus and of course gpu cores and npu cores and other things and then licenses them there to other companies like qualcomm samsung mediatek or whoever and on the risk five side you've got companies like sci-fi andes technology they also design risk five cores and they license them to other so in that sense arm and sci-fi and anti-technology and other companies they're all doing the same thing they're designing a cpu core and they're licensing that design to other people and you pay for that design now some companies have an arm architectural license mean they can design clean room arm compatible processors that's what apple has that's what nvidia has that's what fujitsu has and many other samsung has one okay and so they allow them to design but they have to be completely compatible uh with the r market there are tests that they need to run to make sure they are remain compatible okay and so there are there is the ability for other companies to design arm processes and they are licensed to do that now some companies design their own risk 5 processors like western digital they design it to go into their hard disk controllers nvidia do to go inside their gpu because they wanted a micro controller that was able to do some things now they can design those but there's no license fee involved so that's the fundamental difference it comes to doing your own architectural stuff companies like apple and nvidia infusers can do that but there's a business agreement risk fire if you don't need that business agreement but as i pointed out to somebody just recently in the comments it doesn't seem to hurt apple's profits at all or nvidia's by the fact that they have to have this relationship because when you have a relationship when you have a business relationship a contract a license then there is a mutual respect and a mutual back and forth technical support and also input into other things that are happening in the architecture and so much more because you're now in a business relationship when something is free there is no business relationship it's just free so we have to talk about performance where are we in terms of performance for risk five cpus and for armed cpus of course sci five has just recently announced the p550 it's p for performance core and it claims to be comparable with the cortex a75 so that's where cy5 are at and probably sci five are making some of the most advanced risk five processes about today so where are they cortis a75 era well after the chord is a75 came the quarters a76 they called it a77 that's called the ace mda they call it a7 10 then of course we also have the x1 and the x2 so you can see that makes the p uh five five zero at least four or five generations behind what arm is producing today and to catch up companies like scia5 and other risk five manufacturers need to make calls that not only uh increase their own performance they need to gain on the performance that arm are releasing each year so now they're four years behind then they need to be three years behind they need to be so that's a significant leap year after year after year to not only do better themselves but to gain on the competition so that's quite a tall order for anybody in any field of technology and just let me give you an example of a real world application the upcoming beagle 5 is a beagle board but using a risk five processor it has a one gigahertz dual core u75 from sci five it will cost between 120 and 150 dollars now the u74 is equivalent to the cordless a55 in terms of performance whereas the raspberry pi runs at 1.5 gigahertz it's a quad core called it's a 72 faster than the a55 and it costs 75 so you can see here there is a real world disparity between pricing and performance between what you can get today using an arm processor and what you can get using a risk 5 processor even though risk 5 is free i thought free meant it was going to bring in all the the heady days of grit no someone's got to design it someone's got to pay the engineers someone's got to have the vision someone's got to have the tech cost money worth talking also about os support linux works on both 32 bit and 64-bit arm and risk 5 cpus and so that's a very well established set of support there android doesn't sufficiently support risk five windows doesn't run on risk five mac os doesn't run on wiz five chrome os doesn't run on risk five but android windows mac os and chrome os all run on arm process android of course runs on arm windows we have windows for snapdragon now see my review of the surface pro x here on this channel mac os of course with the m1 processor runs on arm and of course there are many chromebooks with arm processors and it's also worth mentioning that because risc 5 allows these extensions then there is nothing to stop companies adding their own extensions and if it's a big enough company then if you don't have that extension you become irrelevant and of course there's a whole big history about what happened with mmx and 3d now and all that kind of stuff way back in the history of intel and amd so andy's technology has the andy's extended instructions which are in quote exclusive performance and functionality and harms and they've added that to their processes and they're not anyone else's processes so you can see there is this danger of risk of breaking up into many different paths depending on which extensions you've used but in comparison all arm chips are compliant to the isa even the ones from apple from samsung from nvidia and they have to pass tests to make sure they are completely uh doing that and that stops any danger of any kind of forking down the road at companies no we've added this functionality and uh you know and we're not going to do what you want we you know it doesn't happen it's all compliant and in fact companies like apple and nvidia all the major partners have had their input into arm v9 because of course they're going to be using it so it makes sense to have them on board for anything that happens with the architecture so what about the future well a big name will likely get into risk five at some point we're hearing that uh intel want to do that but it means to getting into it beyond their proprietary needs so a lot of fanfare has been made when nvidia or western digital user risk five but of course they're just doing it for their own internal use nvidia uses a risk five in its gpu because it needed a micro controller and a risk five was uh just as much a good idea as any other but they don't sell that microcontroller to anybody else so it's only when some a big name gets involved in risk five and it's then selling that uh beyond you know as a processor or selling the iap or something like that will win it will be interesting and that's why intel sniffing around uh to buy psi five could be interesting and risk five will continue to grow in the microcontroller market there's no doubt about that but we're still waiting for a popular prevalent risk five arduino alternative and that does not yet exist and as i said the beagle but five won't rival the pie in terms of cost or in terms of performance however linux capable risk five cpus will continue to be made and they will continue to make progress uh like the recent announcements uh but they are still a long way behind what arm are offering today on the arm side arm presses will continue to push their way into laptops and desktops with the help of apple and qualcomm and microsoft and google these will the areas where we're seeing uh arm process will continue to expand and of course that's also true in the service space with the neo-verse processors and our v9 is setting the scene for the next decade of armed processes so a big announcement in terms of what it can do and what they're going to do big emphasis on security stop this malware stealing things from one memory to another bit of memory because it shouldn't have access to it all of the spectra and meltdown things that we've seen all the runs that followed after there's been quite a few of them uh trying to get around that in a hardware level and the only other question that remains is will there be a knock-on effect if nvidia completes its purchase of arm will nvidia abandon risk five for its microcontroller for example what's going to happen uh there and of course that's an unknown at the moment but i do have a video about nvidia buying arm if you want some more information about that my name is gary sims this is gary explains i really hope you enjoyed this video okay that's it i'll see in the next one [Music] you

Channel: Gary Explains

Views: 205,988

Keywords: Gary Explains, Tech, Explanation, Tutorial

Id: GyWyikB2hFs

Length: 22min 19sec (1339 seconds)

Published: Thu Jun 24 2021