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This is probably going to be a hyper parallel fixed point / integer engine like TPU gen1. Doing fast matrix multiply over really small fields is very subpar on
by highd 9y ago
This is probably going to be a hyper parallel fixed point / integer engine like TPU gen1. Doing fast matrix multiply over really small fields is very subpar on CPUs and GPUs. That was the initial reasoning behind TPU gen1 - improving runtime performance.
One question is if it will architecturally be closer to a GPU or an FPGA. The field moves so fast that it might make sense to "future-proof" a bit with a live-reconfigurable FPGA.
- imh 9y agoHow do FPGAs compare on space and power? Would differences be enough to matter for mobile?
- highd 9y agoI don't think space is an issue, but an ASIC designed exactly for a workload will always beat an FPGA on power. But if you don't know the workload exactly or don't have the money to fab an ASIC then an FPGA will be superior if the workload is a bad fit for CPUs or GPUs. So if you can save (2-10)x power on some unknown ML workload in the future that might be preferable to (10-20)x on some fixed workload with a fixed-point ASIC. I.e. Bitcoin mining went GPU->FPGA->ASIC, each with more investment required to design but higher overall performance in Hash/W. But that workload is known exactly.
- blackguardx 9y agoSpace is only an issue because it is directly correlated with unit cost.
- seanp2k2 9y agoI doubt they'll do an FPGA. Devices are too concerned with battery life to be running that, plus their margins would suffer or it'd be even more expensive.
- aswanson 9y agoProbably worse on power consumption as well as price per MIP.
- blackguardx 9y agoFPGAs are pretty bad space-wise and power-wise compared to straight up ASICs. Apple could make some blocks highly configurable, but even an FPGA designer wouldn't use FPGA fabric to do multiplication if they cared about performance. FPGAs are a mix of general purpose logic blocks (the fabric) and dedicated blocks like multipliers, dividers, PLLs, memory, serializers and deserializers, etc.
- highd 9y agoThat's what I'm thinking - some sort of configurable FPGA like fabric around a bulk of TPUv1 style cores, maybe for routing outputs around so you can do some nice pipe-lining like you might want with CV on video.
- jacquesm 9y agoI'd bet on this being an ASIC, doing this on an FPGA with any serious size matrix would require a very expensive FPGA, whereas an ASIC would allow more gates in a smaller volume and would consume less power to boot. From the manufacturers point of view phones not being future proof is a feature, not a bug, that way you'll upgrade to that new shiny item which will keep the profits rolling in.
- wklauss 9y ago> From the manufacturers point of view phones not being future proof is a feature, not a bug, that way you'll upgrade to that new shiny item which will keep the profits rolling in. I don't think a better AI chip will be a convincing argument to change a phone one year later.
- RandomBK 9y agoNot if you put it that way. Apple can simply make new AI features exclusive to newer phones with updated versions of the chips. If they open the chip up to developers, this effect can spill out to the app store. That would then provide the impetus to push consumers to upgrade.
- LrnByTeach 9y agoYou nailed the Apple plan, they did exact same thing staring from Introduction of Siri (4S?), ... then Force Touch etc. With each iteration of phone, they add a shiny new feature that is ONLY available on the newer model.
- savoytruffle 9y agoSiri was only available on new iPhones from then on, but it's now available on regular Macintoshes going back like 7-8 years.
- moonforeshot 9y agoi don't see how force touch can be added to older hardwares...
- rtkwe 9y agoIt'll be an ASIC so more GPU than FPGA. The real reason to upgrade the chip would be to add more transistors rather than any real instruction set upgrade so the FPGA doesn't really get Apple anything other than cost and wasted space.
- djrogers 9y agoYou don't put an FPGA in a device you're going to sell 200M+ of. The cost per unit would be way higher than an asic, and your just going to come out with a better version next year anyway so why bother? I foresee it as similar to their M series co-processors - the first one was pretty basic, and more sensors and jobs have been given to the newer ones each year.
- rch 9y agoIIRC there's already an FPGA in the iPhone.
- deleted 9y ago[deleted]
- Retric 9y agoThere is a tiny one in the iPhone 7. But, that's for flexibility on current tasks not future proofing. In terms of AI there is little reason to run it on the phone unless it's heavily used or needs or be low latency. Consider if they add a 100$ of computing power to a phone that sits unused 99% of the time they can just build a server using those same 100$ worth of parts that can then serve 100 phones saving 90+$ per phone including upkeep etc. PS: This is the same logic why Amazon Echo is so cheap, it simply does not need much hardware.
- dnautics 9y agoFpgas are generally power hogs, which makes sense considering how they work.
- petra 9y agoMythic is working on analog/digital neural network chips. Some others also. Much better power-consumption. Maybe Apple aims on those ? it will certainly achieve a much higher WOW factor, which is key here.