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> Moore's Law is still alive and kicking (contrary to what many claim)! That statement is so often misunderstood, in multiple ways. First off, Moore's Law isn
by mtgx 9y ago
> Moore's Law is still alive and kicking (contrary to what many claim)!
That statement is so often misunderstood, in multiple ways.
First off, Moore's Law isn't technically about performance increases. It's about doubling of transistors every 2 years on the same die space. We still got that on CPUs until very recently, even though CPU performance has stopped doubling every 2 years like 15 years ago. But now even the transistor count doubling doesn't happen every 2 years - for CPUs. If that were to happen we'd all have 32- or 64-core laptops by now. And even then the performance wouldn't be anywhere close to 64x (compared to single core).
The second misunderstanding, which exists in your post, too, is that most people refer to Moore's Law dying when they talk about CPUs (especially if we discuss performance).
However, GPUs have indeed kept doubling or so their performance every 2 years, also until very recently. Now it's more like a 30% improvement per year, or 70% improvement every 2 years, which is still way better than CPUs.
And the reason for this is because GPUs pretty much scale with number of cores. If you have 4000 CUDA cores in 2017 for 150W TDP and a $1000 price, then you're going to have let's say 7000 CUDA cores for 150W TDP and $1000 price in 2019, and the performance will be 70% greater. It doesn't work like that for CPUs, and it hasn't for like 15 years.
- mrb 9y agoOn a GPU more transistors = more compute units = more performance. Hence my over-simplification of Moore's Law. I strongly disagree that the rate of CPU perf improvement has slowed down "15 years ago". What a laughable statement. You have to look beyond core count to gauge performance. Microarchitectural improvements, new instruction sets (SSE, AVX), bigger caches, etc certainly still help keep the pace. Have a look: https://www.hpcwire.com/2015/11/20/top500/ https://www.hpcwire.com/2015/11/20/top500/ In particular: https://6lli539m39y3hpkelqsm3c2fg-wpengine.netdna-ssl.com/wp-content/uploads/2015/11/TOP500-SC15-Tech-Trends-Scalar-Processors-Moores-Law-is-fine.png https://6lli539m39y3hpkelqsm3c2fg-wpengine.netdna-ssl.com/wp... Also perhaps you get confused by the fact the average wattage of CPUs sold to consumers is dropping. If, from the performance of a 60-70 watt Netburst Pentium 4 from 2001, you project the expected performance of a 2017 CPU according to Moore's Law, then you should look at today's 60-70 watt CPUs, not at modest 10-20 watt CPUs that seem to be quite popular these days.
- deleted 9y ago[deleted]
- sqeaky 9y ago> Moore's Law isn't technically about ... Moore's law is fuzzy and has been for a while. I doubt if even Moore has the authority to say what it is about anymore. When one person hears "Moore's law" or any other words what are the chances the person hearing those words is thinking the same thing as the speaker? For some words the listener hears the same thing the speaker intended, but I don't think it is for these words anymore. Performance is still exponential the practical of Moore's law is still real.
- bluedino 9y ago>> And the reason for this is because GPUs pretty much scale with number of cores. >> It doesn't work like that for CPUs, and it hasn't for like 15 years. It's more the workload than anything - CPUs scale very well with the right tasks. Nobody gives GPUs the 'wrong tasks' that don't scale