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ARM Unveils Next-Gen Processor, Claims 5x Speedup
unts writes "UK chip designer ARM [Note: check out this short history of ARM chips in mobile devices contributed by an anonymous reader] today released the first details of its latest project, codenamed 'Eagle.' It has branded the new design Cortex-A15, which ARM reckons demonstrates the jump in performance from its predecessors, the A8 and A9. ARM's new chip design can scale to 16 cores, clock up to 2.5GHz, and, the company claims, deliver a 5x performance increase over the A8: 'It's like taking a desktop and putting it in your pocket,' said [VP of processor marketing — Eric Schorn], and it was clear that he considers this new design to be a pretty major shot across the bows of Intel and AMD. In case we were in any doubt, he turned the knife further: 'The exciting place for software developer graduates to go and hunt for work is no longer the desktop.'"
I for one certainly hope that ARM gets a chance in the more mainstream market; the more competition for Intel, the better!
That would really shake up the Wintel alliance.
"I've got more toys than Teruhisa Kitahara."
It's part of maintaining cache-consistency (I presume between multiple processors etc.) http://infocenter.arm.com/help/topic/com.arm.doc.ddi0407e/CHDFJICC.html
I thought most of the interesting stuff took place on the server?
Well either way, I wish them luck. Having competition and diversity in the processor market is a very good thing and forces everyone to step up to the mark, benefiting everyone.
And if they've managed to keep the power envelope down then even better.
32-bit addressing was seriously impressive in 1987, compared to Acorn's then-current machine with 32KB, including video memory. But now even smartphones are starting to come with 512MB, 1GB of memory. Does ARM have a strategy for getting past 4GB?
"It's like taking a desktop and putting it in your pocket," said Schorn.
That's gotta be one of the most uncomfortable marketing images ever.
"Is that an ARM in your pocket or are you just glad to see me?"
I don't know the heat dissipation figures, but I can safely say I have never yet seen an ARM processor with a heatsink. As for power consumption a quick google seems to show that an 800MHz OMAP3 draws around 750mW at full load. This new A15 core is supposedly going to have similar figures.
No, nothing at all to do with DRM. Snooping refers to checking the contents of other caches for cache coherency. Cache comes from the French, meaning hidden - it is memory that the programmer doesn't see directly, so the CPU has to act in exactly the same (programmer-visible) way as if it were not there. This is pretty simple when you have just one core, but when you have more than one it becomes difficult.
If you have two threads, on different cores, both accessing the same memory, then each will try to pull it into the memory into the cache. This is fine, as long as both are reading it. When one writes to it, the copy in the other core's cache must be updated or the two threads will have an inconsistent view of main memory. This is called cache coherency. The snoop control unit is responsible for all of the cache-to-cache communication. Because ARM cores typically live on a die with other units that share the same RAM, it is also responsible for ensuring that the caches remain consistent with modifications to RAM by the other coprocessors.
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Right now my Samsung 5000 series LED tv runs an arm with busybox linux as the firmware. It is only a matter of time before TVs become fully internet capable and use usb 3 for storage. I also have seen demos of touch screen remotes that have qwerty capability for your TV. So the only thing missing is a simple cursor system and presto you have it all. Seeing that arm processors are becoming this powerful the market for all in one home entertainment devices is there. If Microsoft does not see this coming and continues to have mediocre support for arm based devices then embedded Linux will continue to dominate the living room. Three of my home entertainment devices are already based on the Linux kernel!
'The exciting place for software developer graduates to go and hunt for work is no longer the desktop.'
Why, actually, why??
I am really really looking forward to a desktop with low power footprint. There is no need here to run MS-crapware; no Crysis or other high-resource gaming.
Gimme a nice desktop, low-low power, that boots to Debian on ARM, and I throw mine out of the window. And I already have a 80+ PSU, single row of RAM, dual-core EE AMD. It still has a 45W TDP; plus AMD does not sell the Energy Efficient (EE) any longer except to OEMs; at least in this country.
Throw out the 24-pin plus 12 V power supply, let's do everything on 12 V, give it 6 USBs, Sata, HDMI/DVI, Ethernet and WiFi. A mini ARM.
And, yes, I want to be able to add a hard disk of my own, maybe a DVD- or BlueRay-Drive, so add some space.
Not with the idea of a standards based chargers but this "Wintel alliance," crap. There is no such thing. x86 chips are used for desktop computers because they are the only things that have been cheap, common, and powerful. MS has no special interest in pushing Intel. DOS, and thus earlier Windows versions, were tied to x86. When NT came out, they abstracted it and indeed you could get NT4 for x86, PowerPC, and Alpha. Let me give you a hint how well those other versions sold. As such, they were discontinued.
Also when it came to 64-bit for the desktop time, MS cast in with AMD. Intel was pushing Itanium, which MS does support on their server OSes, but AMD's 64-bit extensions, called amd64 internally by the Windows tools, were what was used for the desktop. So you can get Windows 7 in x86 and x64 variants, and Server 2008R2 in x64 and IA64 variants.
Now for Windows CE (also the basis for Windows Mobile), their mobile/embedded OS, well then that runs on all sorts of things. x86, MIPS, ARM, and SuperH. Again, more could be added, this is just what is supported as that is what there is currently a market for.
What it comes down is they support the architectures that are used in the markets their OSes work in. There is no ARM version of Windows 7 because there are no ARM desktops that demand it. Porting an OS to a new architecture and maintaining it is not a zero effort task, so it isn't done unless it is worth it (unless it is NetBSD :D).
Also the reason x86/x64 continues so strong on the desktop is it works so well. It provides binary compatibility will all your old apps, and the CPUs that use it are fast and cheap. Thus far, I've seen nobody who can beat Intel and AMD in that market. Sure there are higher end CPUs that cost more and use tons more power, like Itanium and Power7. There are also chips that use less power and are cheaper, the ARM. However I've yet to see the chip that does better in their market, as in can do more operations with the same or less power and costs less.
So you want ARM desktops? Well first an ARM CPU that is competitive in that market has to come out. Competitive, please note, doesn't mean "Barely can compete with the low end." I'm talking something that makes you say "Wow, that is faster than my i5, and for less money." Then maybe there's interest. Should ARM desktops start to become popular, you can be pretty confident MS would move Windows over to them.
But please, stop pretending like there's some sinister conspiracy to keep alternate architectures down. There are only two reasons for the x86 dominance:
1) Compatibility. It is far nicer to have a chip that works with your old stuff. People will default to what's compatible unless given a good reason. I'm not going to pay the same amount for a CPU with the same performance that doesn't run my apps as for one that does. So whoever wants to break in to the market has to offer a good reason. Less cost, more performance, etc. Probably still need have a good emulators to support older apps.
2) Intel is really, really, good. Everyone likes to hate on Intel because they are big and there's automatic underdog love on Slashdot, but they are good at what they do. They spend a ton on R&D and the result is they are almost always ahead in terms of fabs and their CPUs tend to offer great performance for the money. Yes, they've bad problems, Netburst (P4) was an example, but currently it is impossible to touch the Core i series. They are fast, do a lot given their power budget, and have a good price.
I know many CS graduates who have thought that the most interesting stuff to play with is in the pocket.
According to this, a typical cortex a9 core draws about 250mW. As this has a very similar architecture (still ARMv7), it should be somewhere in similar regions, maybe more, as they boosted the frequency. So I guess a 16 core version will draw something like 4W+, maybe more. Non-the-less, this is still an incredibly good figure for a web server type processor, though a little heat sink might appear.
I'm only guessing here though, based on previous figures. There is no practical data so far on the exact figures.
They royally kick Atom's ass,
The Atom looks bad on work/watt, but still wins in raw performance.
but I have no idea how they compare to Alpha.
The alpha is a "floating point monster", or was anyway, and since ARM doesn't focus on floating point I doubt they compare. The Atom might keep up though.
I'm currently working with several concurrency development groups within the SUNY system; we are partnered with Oracle, Google, and IBM as well as a few others. Upon mention of ARM not a single co-worker has been able to resist going into rant mode about the lack of reasonably quick CAS and LL/SC implementations. Further, barriers and fences apparently take so long to establish that to fake a CAS you are looking at three to six hundred cycles compared to about a dozen for current generation i7's and SPARCs (optimistic CASing). Can anyone speak to the implementation of the features on this new chip?
Have run all of these, in anger, in production, at one point or another.
I still have an extremely soft spot for the RAQ2, 64 bit MIPS processor.
Image link - http://dev.gentoo.org/~vapier/pics/mipsel-raq2/inside-main-board.jpg
Nota Bene, NO HEAT-SINKS OF ANY KIND, and yet these puppies could saturate a 10 Mbit connection (of course this was the days before flash and stuff) and the whole mainboard used about 10 watts, most of which was the RAM, the biggest power eater was the IDE HD.
Downside was it was MIPS, which is a lot like the downside of the Acorn ARM based A series and Risc-PC series, eg not x86 compatible, ergo not mainstream.
Now that ARM is used is zillions of other devices, ARM is no longer the backwoods, everywhere except in "a computer" eg desktop or server.
Which means ARM on the desktop or ARM on the server won't suffer so badly for not being x86... it will still suffer, but not so badly.
RAQ3 went away from MIPS to x86, IMHO because of this accessibility and availability of x86 code, not because it was technically superior to MIPS... one RAQ3 wasn't more powerful than two RAQ2 in any sense except power consumption and thermal rejection.
In practical terms x86 has gone nearly as far as it can go, both in terms of light speed and die size, and thermal dissipation per cubic mm, so the alternatives are catching up, not so much because of sheer lifting power, but because of thermal dissipation per cubic mm they still have "development room" left to play around in.
The next 5 years or so are going to be interesting, as this "development room" is explored and used up, and especially so if anyone comes out with a robust cross architecture compiler / translator.
http://slashdot.org/~GuyFawkes/journal
While people love the idea of wireless, it just isn't going to happen for everything. In terms of power, it is impossible basically. You can do inductive charging which is technically wireless, I suppose, but it doesn't really fix anything. You device has to sit directly on the charger, which of course has a wire back to the outlet. It's been around forever, electric toothbrushes use it because having a waterproof system is important, but it just isn't that useful over all. Better to just use a wire, or have exposed connectors in a dock. Cheaper and more efficient.
You'll never see actual wireless, longer range, power until we discover some way of getting around that pesky inverse square law thing.
As for communications, well bandwidth is just an ironclad bitch, and one with no easy solution. The very best wireless technology can, in the best circumstances, compare favorably with old ass wired technology. Have a look at Wireless N as an example. If you have a good multi-antenna transmitter and receiver and you aren't too far away and there's no interference you can get 300mbps raw data rate. That works out to 100mbps of throughput. Oh yay. A whole 100mbps, you know, what the cheapest of the cheap wired ethernet can handle.
The real problem starts with video. So HDMI needs 2.8gbps so support 1920x1080 @ 60Hz. That is just the video, no audio. If we start to want things like higher resolutions, higher refesh rates/3D more than 8bpp and so on, it takes even more. Can't do that with any cheap wireless tech these days.
Also when trying to make ultra high bandwidth wireless you run in to the problem that is Shannon's Law. Bits per second is related to bandwidth and SNR. Well SNR is something you can't do much about with wireless. The noise level is what it is, so you have to increase bandwidth to increase throughput. That means increasing frequency. Here there's a problem, the higher the frequency, the less ideal the transmission characteristics. The high GHz stuff, what you need for big bandwidth links, gets rather directional, is quite short range (air even attenuates it) and doesn't pass through hardly any barriers, even walls. This is all aside from the general difficulties making stuff that signals cheap at those frequencies.
You also get the additional problem of needing even more bandwidth to avoid contention. With wires, there's no interference. I can HDMI to three displays side by side, and there's no problem. With wireless, each needs its own channel, which just further increases the amount of RF bandwidth you need to make things work.
Wireless is useful, don't get me wrong, but I don't see this "All wireless, all the time" future you do. You could spend a lot of money trying to do wireless video from your Blu-ray player to your TV, or you could just get a cheap cable. Given that both devices are going to be plugged in anyhow, is it really such an issue?
That means back to segmentation. That isn't a killer problem, but it is significant. In terms of how that works in modern computers, you can see it on Windows systems on Intel PAE processors. Basically the OS gets access to all the memory in the system, but it has to be divided up to be used. In the case of the Windows implementation, the kernel can get only 2GB and each application can get only 2GB. You can have multiple 2GB apps running, but they can't have more.
For an app to get more, it has to implement memory management internally. Basically it talks to Windows and gets a range of memory set up that will be paged, it then gets more RAM allocated and specifies how to page through it. Called AWE and used by a couple apps, like MSSQL. Of course that is complex on the part of the app and would be problematic if you had multiple ones running.
Also it makes task switching hit the system harder over all, because of the segmentation.
So i mean it works, don't get me wrong, I have seen servers doing it. However 64-bit is a much, much, cleaner solution both OS wise and software wise. It really is a hack when you get down to it.
I like current desktop CPUs, which have larger virtual address spaces than physical. You are right, 40-bits is fine for now. As far as I know the top end Intel CPUs only have 48-bits of address lines currently. No reason to implement all 64-bits, you wouldn't use it. However having a flat virtual memory space is something that is extremely useful. There's a reason everyone wanted to move to that with 32-bit CPUs as soon as it became feasible. We don't really want to go back to segmentation.