Gadgetory

cpus processors systems on a chip we've all got them what do they do what are they for and what kinds are there this is pocket now I'm Joe Levi that's what we're going to talk about on today's episode of the android guy weekly so buried inside your tablet or your phone is something called a processor or a core or a system-on-a-chip one of those all mean well for that we're going to go back to computer technology and terminology way back in the day you know a long time ago in the 90s we had computers just like we had today they weren't as fast but they had all the same parts kind of those parts while I had a CPU a central processing unit that thing did well almost everything except not all that much what it did was it processed instructions that's all that it was meant to do people thought it was really important and indeed it was but it wasn't as important as they thought because they had a whole bunch of other chips on their motherboard you like that tech jargon up the wazoo in this episode huh so they had a whole bunch of other chips they had an ALU an arithmetic logic unit they had a memory controller which ironically controls the memory they had all this other stuff a North Bridge chip that controlled the top side and more important parts of the the motherboard and a South Bridge that controlled well the lower side and the less important parts of the motherboard and all this stuff the peripherals that plugged into them there were lots and lots of chips the nice thing about that is you could customize if you were a manufacturer what you wanted on your motherboard so you could really differentiate you could make a whole bunch of different stuff and make your stuff stand out from your competitors stuff the CPU on the other hand that was something they said well let the end-user have a little bit of control and flexibility and pick what they want to a certain extent that worked and that metaphor carries through even through today well as things progressed we started getting more and more stuff on that cpu for example today we have a CPU that not only has the CPU on it it has the ALU for processing arithmetic it has the memory controller in most cases and some other stuff there are even multimedia extensions remember those Pentiums with MMX yeah that's what that meant nobody really ever knew at the time but that's what it was for so we got all this stuff and it's building it all into one chip well that means there's less flexibility on the motherboard side to customize and to add different features and benefits based on you know what the Southbridge is and does or how powerful the ALU is or what the Northbridge is ah but we kind of kept the Northbridge in the Southbridge separate on desktop computers come back to that in just a minute the advantage is one chip did a whole bunch of stuff and it did it faster especially when you're talking about the memory controller because you're really pumping memory in or stuff from the memory into the processor processing it and then spitting it back out to the memory out to the RAM that's pretty much a day in the life of a cpu with the memory controller even right next to the CPU slows things down put it on the CPU Wow goes really really fast so you've got cash you've got memory you've got all this stuff built in and it's really really good it makes the chips smaller they're less chips that makes the overall system less expensive though it makes that CPU more expensive okay enough with desktop PCs all right great we're going to talk about one more thing but we're going to compare that to where we are with our Android tablets and really most of the other smartphones and tablets out there today you see these devices these computers that we sit on our desks are having our laps they're what's known as sisk chips they're complex instruction set computing sounds really really neat doesn't it okay what about our phones well phones are based on risk reduced instruction set computing now the difference is between those two are all night and day one is really really wide open you can do anything you want with it you write these really complex instruction sets you send them to the the processor the processor processes all these complex things and well the more complex something is them longer it takes to process it but it can do it it's flexible that way risk r is c it's reduced it's not as complex because of that it doesn't have to run as quickly to accomplish the same things but it pushes the processing of the complexity over to the code so you have to take complex code somehow reduce it send that reduced set over to the processor the processor thinks about it does whatever it spits it back out but you can get a lot better speed out of it as long as the software that's pre-processing the complex instructions to reduced instructions is really efficient it's a little bit of extra overhead but it has some advantages so one of the most popular architectures of RISC processors is called arm it used to stand for something but nobody really cares anymore because it's just ARM arm makes a design it's about it yes they make some reference samples but you can't just really go out and buy an ARM processor you can buy somebody else's processors that's based on arm so there are a lot of different versions of this arm architecture we're up to version 7 right now I know it's going to get kind of confusing arm v7 it's where we're at it's 32 bit honestly almost everybody uses arm v7 you'd be surprised let me review this list TI has their omap4 it's an arm v7 Exynos that's samsung arm v7 snapdragon arm v7 nvidia's tegra it's an arm v7 v8 it's going to come out sooner or later it they're making a lot of progress it's 64 bit it adds a whole bunch of more stuff that's going to make things just tons and tons faster but where are we today we're at arm v7 that's not bad because arm v7 has lots and lots of different levels inside of it in fact you're familiar with the cortex name so we've got the cortex a8 we've got the cortex a15 these are still v7 arm v7 chips what do they do well honestly I could devote hours to that and i'm sure i would put you all to sleep i don't want to do that you can go and research what each one of those does and why it's different and and the benefits what we're going to talk about here is more high-level you CTI makes their omap4 based on the arm v7 and depending on which omap you're talking about it includes a different cortex version of the arm cortex so they're just a lot of variables and everyone would get confused and lost really fast meet probably first but the difference is between desktops and mobile processors we're putting even more stuff on to the mobile processors instead of just taking a cpu and an ALU and a memory controller well over here on these SOC s these systems on a chip we're putting not only those ok so we've got the CPU we've got the ALU we've got the memory controller we're usually also putting a GPU a graphics processing unit a video card right on the chip we're usually putting the Northbridge on the chip and the Southbridge on the chip many many many times we're also putting our cellular antenna processors those chips on to the CPU the whole system on a chip now the advantage there is it's one chip so you'd think that combining everything onto one chip would make things easier and simpler well it makes things smaller it makes things more power efficient so you need smaller batteries or your larger batteries can last longer to run them we won't get into that argument we've already that heavenly but the disadvantage is now you're differentiating based on that one chip and unlike desktop PCs you can't simply pull the chip and replace it with another one wouldn't that be cool hey you know what I don't like this a TI OMAP that I have on my phone I want to go with the Tegra 3 so I'm just going to pop it off and pop my new wouldn't that be cool and I have nothing against TI OMAP by the way just using that as an example but we can't do that they're soldered on the board they're buried underneath circuitry and you just can't do it so you have to get a new device that's kind of the other side of that coin yes you're saving money up front yes you're putting a lot of stuff into one package up front but when you want to upgrade or when you want to change you have to change the whole thing it's a system-on-a-chip you got to replace the whole thing and that unfortunately means your phone so where does that leave us every different manufacturer of processors and other phones is doing something different but most of them are using this arm architecture and they're usually paying about seven cents for licensing per unit to be able to license that architecture they're adding their own stuff to it again this is a system-on-a-chip and arm is just the cpu the cortex that's the other stuff that's added in okay not to be too terribly confusing there so TI is doing their own thing they're putting particularly signal processors because that's what ti does best in with their SOC s Samsung Exynos and before that the hummingbird they're doing all kinds of cool things with there's the snap dragons need i say more I mean come on that's what everybody uses HTC dell sony wow they're great and then of course nvidia's tegra which are powering some of our higher and tablets and some phones do they have any phones yet I know they were going to sorry in bed just had a jab at you a little bit there but everybody is doing something different but they're all starting from the same foundation now when that foundation improves we're going to see some new cool stuff come out from all of these different manufacturers who are just using furman as the foundation upon which their building everything else so really the discussion is more about arm and how cool it is but because it's this whole system on a chip thing with all the extra additives built into it you know bluetooth for versus bluetooth 2.1 Wi-Fi n versus Wi-Fi g all that stuff and of course what what video processor they're using for graphics that's the cool part hopefully I've removed some of the cloud and mystery around CPUs and haven't added more to it but once we get this deep it's hard to get really deep without you know asking more questions than we answer so did I get your questions answered about CPUs and systems on the chip SOC s how they related where they came from what they do for us in some of their drawbacks if I did great give the video a big thumbs up if I didn't or if you caught something that I said wrong or would like to clarify or add more information perhaps what you like best about your SOC that's powering your phone or tablet head over to pocketnow.com leave a comment let us know participate in the discussion and help everybody else who just got lost by everything I just said understand the concept a little bit better because i'm sure you can explain it in a different way that i can that others might be able to understand better complex topics but that's one of the things we like about the android guy weekly for pocket now i'm joe levi you