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How the SoC Is Displacing the CPU

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31–40 of 52 posts

Re: How the SoC Is Displacing the CPU

#31
post #27

Earlier quoted context omitted.

http://shop.fairphone.com/fairphone2.html#technical-specific... That lists the various bands for the mobile radios.

I saw that, but it's strange that they'd make it w/ a capable quad-band radio and -still- declare it's only designed for Europe. I'm not a cellular expert -- are there other considerations outside the frequencies that it supports ? If not, it seems like a good global phone, no ?

I can imagine concerns with stuff like allowed WiFi bands...

Re: How the SoC Is Displacing the CPU

#32
post #12
post #9

"Apple A9X SoC offers 64 bit desktop-class computing enabling a handheld tablet to go toe-to-toe with a state-of-the-art laptop CPU from Intel" Yes and no. Most of the innovation in top-end x86 CPUs goes towards multicore and multi-socket scalability. My desktop is almost 10x faster than an A9X -- and nobody manufactures an ARM SoC that has 100 W thermal envelope but delivers the same speed as a Xeon v3. Intel manufa…

nobody manufactures an ARM SoC that has 100 W thermal envelope but delivers the same speed as a Xeon v3 Look at Cavium ThunderX: 48 ARMv8 cores, very high performance, 95W.

there arn't a lot of workloads a laptop is going to care about that utilize 4 cores, let alone 48. Each indivual core is going to be 1/10th the preformance or less of an intel one.

It would feel dreadfully slow by comparison.

Re: How the SoC Is Displacing the CPU

#33
post #24

Earlier quoted context omitted.

PoP "Package on Package" which puts the memory directly on top of the CPU has been around for a while. https://en.wikipedia.org/wiki/Package_on_package

PoP is nice, but what's really hot is SRAM right on the die. I've been playing with a Renesas part (RZ/A1H) that has 10MiB snuggled up to the A9 core. Doesn't solve everything, but when your app heap and stack are in there it's a great jump in performance for the price. It can also mmap external QSPI flash, you can create a system with no external SDRAM at all if you wanted.

Scratchpads have all kinds of benefits plus are easier to implement than caches. Unfortunately, the market rejects them mostly in Intel's sector. So, we have things like IBM using a ton of onboard cache in high-end chips that's not quite SRAM speed. Worse is better. (shrugs)

Re: How the SoC Is Displacing the CPU

#34
post #28
post #15

Earlier quoted context omitted.

> Intel manufactures different state-of-the-art laptop CPUs. Apple SoCs can compete with the ultra-low voltage Intels, but not with high-end i7 HQ/MQ series. I think his point was that a $15 Apple chip crushes a $150 Intel Core M. Core M chips have extremely little bang/buck value, as do the new "Celerons" and "Pentiums" that are dressed up $110+ Atom chips.

That $15 vs $150 comparison is stupid - where I can buy a A9 for $15? The A9 is a great jump forward by Apple - and I'm impressed by my iPhone 6s - but I'm yet to see the "crushing" benchmark, except for those that are skewed by SHA results.

Not to mention people buying the x86 chip were buying performance and x86 compatibility. Proper comparisons for cheap or energy-efficient x86 would be best made against VIA's CPU's. Maybe also the Loongson with x86 emulation since they can give you speed in MIPS mode and x86 compatibility where needed. Don't know their price, though.

Re: How the SoC Is Displacing the CPU

#35

Earlier quoted context omitted.

Yeah, and the integrated GPUs, at least the entry level ones, do suck. My Acer netbook is barely able to play 360p videos, 720p if you're lucky and 1080p - no hope. My cheap smartphone can play 1080p without a single dropped frame.

On neither of those platforms is the GPU doing the video decode. On your phone there's a dedicated DSP. On your netbook the CPU is pulling up the slack. There's a lot of serial work in decoding videos (like huffman decoding) that doesn't translate to standard GPUs without a little extra silicon.

One of them should just rip off and modernize the SGI Onyx or Octane approaches. They did amazing stuff with 150-200Mhz CPU's by great, HW architecture. :)

Re: How the SoC Is Displacing the CPU

#36

This is a bit silly. A9X and other mobile SoC are in absolutely no way comparable in performance, on any metric, with desktop CPUs. You do not get 150W performance from a 10W chip, particularly not when you are lagging in process node.

I don't think there is much lagging in the node size with the A9 family in comparison to Intel's mobile chips. A9 is a 14-16 nm FinFET design. Not much different than Intel's 14 nm FinFET for core-M. The A9X is clocked at 2.26 GHz compared with a Skylake core-m7 clocked at 1.2-3.1 GHz.

Despite what you said, you in no way addressed or contradicted his point. Clockrate and nm don't tell you performance. Intel's internal architecture has tons of tricks to get more bang for buck out of their cycles. Plus lots of accelerators with extra instructions. Plus modifiable with microcode update. So, a proper comparison would be a number of workloads on each that people use for desktops.

Note: I still haven't seen a mobile that outperforms my old Core Duo 2 laptop. Always slower in both delay and throughput.

Re: How the SoC Is Displacing the CPU

#37
post #14

Earlier quoted context omitted.

You're not missing anything -- the article is dumb. Of course we're eventually going to integrate everything, for the same reason that no one uses separate interrupt controllers or separate Northbridges. We have too many transistors we don't know what to do with. Edit: I think the interesting question is what won't be integrated? RAM and Flash because they use different processes. GPU? Intel and ARM integrate it, but…

Also I would like to know how much die space is wasted on IBM PC backwards compatibility crap in Intel systems (think A20, cascading interrupt controllers, 8086 support, legacy boot, etc)

Not much, I guess. The original 8086 had only around 30000 transistors. The die of a modern quad-core Intel chip accommodates more than a billion transistors, about half of which are dedicated to the GPU and maybe around 10% are taken by a single core. That would roughly translate to 100 million transistors per core (including their L1 and L2 caches), so the footprint of the legacy cruft should be negligible.

Re: How the SoC Is Displacing the CPU

#38
post #16

Intel biggest inroads in SoC market happened when it was giving away Atoms below cost ($5, Mediatek/Rockchip price point) while losing $3-4 Billion. Year after year since 2013. Their plan for 2016 is selling LTE modems below cost to Apple.

How is it even legal ?

Re: How the SoC Is Displacing the CPU

#39
post #14

Earlier quoted context omitted.

You're not missing anything -- the article is dumb. Of course we're eventually going to integrate everything, for the same reason that no one uses separate interrupt controllers or separate Northbridges. We have too many transistors we don't know what to do with. Edit: I think the interesting question is what won't be integrated? RAM and Flash because they use different processes. GPU? Intel and ARM integrate it, but…

Also I would like to know how much die space is wasted on IBM PC backwards compatibility crap in Intel systems (think A20, cascading interrupt controllers, 8086 support, legacy boot, etc)

An intel 8088 processor had a 22mm^2 die size at a 3000nm process node size. A modern x86 processor has a ~200mm^2 die size at a 14nm node size, a die size that is 10x larger with features 200x smaller.

Even if a modern x86 chip had to put an entire 8088 on die for legacy compatability (which it definitely would not need to) we are talking less than 0.1% of the die space being taken up by legacy features.

The idea that x86 is somehow doomed to be inefficent because of legacy baggage is quite simply massively overblown.

Re: How the SoC Is Displacing the CPU

#40
post #38
post #16

Intel biggest inroads in SoC market happened when it was giving away Atoms below cost ($5, Mediatek/Rockchip price point) while losing $3-4 Billion. Year after year since 2013. Their plan for 2016 is selling LTE modems below cost to Apple.

How is it even legal ?

If Intel wants to lose a few billion dollars while gaining almost no market share, why shouldn't it be legal? It was a massive failure all around, with basically only low-end tablets and some Asus phones using Intel's fire-sale chips.

Had it succeeded I'm sure we could have seen some lawsuits but it didn't so we don't.

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