[HN Gopher] Megatron-Turing NLG 530B, the World's Largest Genera...
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       Megatron-Turing NLG 530B, the World's Largest Generative Language
       Model
        
       Author : selimonder
       Score  : 66 points
       Date   : 2021-10-11 13:13 UTC (9 hours ago)
        
 (HTM) web link (developer.nvidia.com)
 (TXT) w3m dump (developer.nvidia.com)
        
       | bane wrote:
       | What's really interesting is that these models are using some
       | non-trivial portion of all easily accessible human writing -- yet
       | humans learn language really well with significantly less input
       | data. What's missing in the field to replicate human performance
       | in learning?
        
         | dlkf wrote:
         | Humans use language to accomplish tasks in their environment -
         | establishing relationships, making deals, coaxing others, etc.
         | By contrast, all neural language models do is predict the next
         | word as a function of the previous word. So far, these language
         | models have nothing at all to do with language learning.
         | They're only valuable insofar as they advance downstream
         | engineering tasks like machine translation.
        
         | visarga wrote:
         | Imagine you lived in a black room and all you can see is a
         | buffer of text scrolling in front of you. Nobody explains what
         | the symbols mean. You don't remember anything medium term, you
         | can only access a short snippet of text at a time and form long
         | term memories gradually. You just look and predict what will
         | come next. Who could become an intelligent person being raised
         | in these conditions?
         | 
         | So they are missing 2 years worth of visual, auditory, tactile
         | and other modalities (grounding), having direct access to
         | change their environment (embodiment) and being part of our
         | society or an AI society (social).
        
         | ipsum2 wrote:
         | One dimension that isn't being considered is that humans have
         | had billions of years of evolution, while neural networks are
         | essentially a blank slate.
        
       | xnx wrote:
       | This reminds me a little bit of the early 2000's where search
       | engines would list the number of indexed pages on their homepage.
       | For language models, does large = good? I'm guessing the quality
       | of the corpus matters as much.
        
         | ewheeler wrote:
         | Maybe? The Scaling Hypothesis[1] suggests that greater
         | capabilities of intelligence may emerge from scaling up
         | 'scalable architectures' to large sizes. GPT-3 exhibits 'meta-
         | learning' capabilities that GPT-2 did not (like learning how to
         | sum numbers)--probably just because its a 100x larger version
         | of GPT-2.
         | 
         | [1] https://www.gwern.net/Scaling-hypothesis
        
         | thunderbird120 wrote:
         | >For language models, does large = good?
         | 
         | The short answer is yes, the long answer is it's complicated.
         | 
         | You could actually think of these models as a type of indexer
         | because, at their heart, what they are doing is memorizing the
         | training data and storing it in such a way that incomplete
         | samples can be used as keys to extract complete samples. The
         | magic happens because the models themselves (even the 100+
         | billion parameter ones) are nowhere near complex enough to
         | actually store all of these possible key value pairs. Instead,
         | the model has to compress its representation of the data which
         | leads to generalization. Larger models can model more
         | complexities which leads to better performance as long as your
         | training dataset is sufficiently large and varied.
        
         | bpiche wrote:
         | I'm not sure it moves the needle on NLU/classification tasks
         | very much, compared to models with many fewer parameters. But
         | it does seem to make the NLG better, which is what Microsoft
         | seems obsessed with lately.
        
       | captn3m0 wrote:
       | Interesting that books3 and The Pile are among the largest corpus
       | used for training - both with copyright concerns.
        
       | trash3 wrote:
       | How has the previous largest model, gpt3, generateda value? How
       | much better is this model at those tasks?
        
       | miket wrote:
       | https://en.wikipedia.org/wiki/Wu_Dao
        
       | bpiche wrote:
       | Wonder how much compute it would cost to train this thing, if you
       | weren't Nvidia..
        
       | posharma wrote:
       | This is great. Now, how do we inference these models
       | economically? It appears there's some kind of competition to
       | train larger and larger models, but the inferencing side of the
       | story seems to be neglected?
        
         | dwohnitmok wrote:
         | Model inference is actually comparatively very cheap. If you
         | have the resources to train a model, you most definitely have
         | the resources to run it.
        
           | shock-value wrote:
           | Does that hold as the workload scales up? E.g. could this or
           | similar models be used as part of a general-purpose search
           | engine whereby (at least) one inference is completed per
           | unique search? Aside from computation, I know these models
           | consume an intense amount of memory -- would that scale
           | horizontally easily / economically? Would it need to?
        
           | manquer wrote:
           | Not necessarily, you train once , you run inferences billions
           | of times maybe. The compute required could be beyond your
           | resources.
        
         | buffington wrote:
         | When you say "inference", do you mean "interface", or is
         | "inference" an ML term I'm not familiar with?
        
           | igorkraw wrote:
           | It's a ML term, inference basically means using the
           | probability model you learned to draw "inferences" about a
           | piece of data. In this context, it means giving the language
           | model some context and using some method (either arg max
           | sampling or something more sophisticated like beam search) to
           | do what amounts to statistical auto implemention on it. As
           | you might imagine, doing this with 530 GB of data at speed is
           | quite energy intensive, even though there are things you can
           | do to compress the model (distillation, pruning,
           | compression/discretization) and specialised inference
           | hardware.
           | 
           | Technically there is some very specific meaning to inference
           | vs. prediction, but it's been heavily overloaded with meaning
           | by now
        
           | sanity31415 wrote:
           | First you train a model then you use it, "inference" is a
           | fancy word for using the model.
        
       | petters wrote:
       | Training data has 0.339T tokens, less than the number of training
       | parameters. A model like that could store all of the training
       | text with 100B+ parameters left for computation.
        
         | visarga wrote:
         | But then you try to predict the next token on a completely
         | unseen piece of the corpus and fail miserably if all you do is
         | store the training data.
        
         | thewarrior wrote:
         | Maybe that's what it's doing under the hood.
        
         | knuthsat wrote:
         | For some reason this issue with model having insane amounts of
         | weights but training data being small is not something that is
         | an issue for modern NNs.
        
           | lucidrains wrote:
           | https://arxiv.org/abs/2109.02355
        
       | macrolime wrote:
       | Will anyone outside of Nvidia be able to access it? GPT-3 at
       | least has an API.
        
         | thenightcrawler wrote:
         | hoping so!
        
       | cs702 wrote:
       | So we now have models with 0.5 trillion parameters, each the
       | weight of a connection in a neural network.
       | 
       | Trillion-parameter models are surely within reach in the near
       | term -- and that's only within two orders of magnitude of the
       | number of synapses in the human brain, which is in the hundreds
       | of trillions, give or take. To paraphrase the popular saying, a
       | trillion here, a trillion there, and pretty soon you're talking
       | really big numbers.
       | 
       | I know the figures are not comparable apples-to-apples, but
       | still, I find myself _in awe_ looking at how far we 've come in
       | just the last few years, to the point that we're realistically
       | contemplating the possibility of seeing dense neural networks
       | with hundreds of trillions of parameters used for real-world
       | applications in our lifetime.
       | 
       | We sure live in interesting times.
        
         | EvgeniyZh wrote:
         | Not all weights are born equal, different paradigms allow more
         | parameters while being less parameter-efficient, e.g.
         | https://openreview.net/forum?id=TXqemS7XEH
        
         | fspeech wrote:
         | A 10 trillion parameter model was mentioned here:
         | https://mobile.twitter.com/ethancaballero/status/14458268620...
        
           | ImprobableTruth wrote:
           | That's MoE.
        
             | rolisz wrote:
             | Mixture of Experts, aka not all 10 trillion parameters are
             | used at the same time, just a subset that is an "expert" on
             | the "task at hand".
        
         | codeulike wrote:
         | Unless we have misunderstood neurons, and microtubules are the
         | fundamental computational unit in which case we are out by an
         | order of magnitude
        
           | eximius wrote:
           | There was a result recently of modeling an organic neuron
           | with 1000 digital neurons.
           | 
           | And even if that result was perfect modeling of the neuron,
           | that assumes perfect and exhaustive _data readings_ on the
           | organic neuron, which is, frankly, unlikely. (Not that I know
           | how to estimate how much it 's missing, but I don't think we
           | fully understand a single neuron yet.)
        
         | singularity2001 wrote:
         | Except that every synapse is not a dumb weight but a highly
         | complex system connected to an even more complex system (aka
         | neuron) which might each be a (super)computer on its own.
         | 
         | Given how extremely bad we are at computing, there is hope (for
         | ai) that the neurons or their circuits are not _that_ powerful
         | after all.
        
           | alecst wrote:
           | Last I heard (and I believe this could be wrong) my professor
           | said that we basically understand how a single neuron works.
           | That like basically if we do X input we get Y output, up to
           | some accuracy. He used this to discuss the idea behind neural
           | networks -- that each neuron is simple enough to model, all
           | we need to worry about is the weights and the dynamics of the
           | network as a whole.
           | 
           | How much of a simplification is that? And how much does the
           | accuracy of such a model matter, in the grand scheme of
           | things?
        
             | visarga wrote:
             | > All we need to worry about is the weights and the
             | dynamics of the network as a whole. How much of a
             | simplification is that?
             | 
             | A lot. Parallel optimization is an art form. These models
             | are trained on static datasets, they can't intervene in the
             | environment to infer causal relations, so they need legs
             | and hands.
        
             | manquer wrote:
             | I would say quite a bit. Adding even a third body makes it
             | impossible to calculate physics with certainty. A complex
             | system with any number of individual components is hard to
             | understand with certainty and/or calculations can become
             | exponentially more complex .
        
             | gisely wrote:
             | Your professor lied.
        
             | sydd wrote:
             | oh finally something that I learned a lot about :)
             | 
             | Such research is the area of computational neuroscience -
             | one thing that such people do is try to model parts of the
             | brain (or just a single neuron) with computers.
             | 
             | A Neuron (=nerve cell in the brain) is a very complex
             | beast. In rough terms they work like this: They collect
             | signals (electrical impulses) via their small appendages
             | called dendrites. when the sum of the signals reaches a
             | certain threshold a large electrical impulse is generated
             | at the cell body that will travel trough its "output"
             | appendage (called axon) that connected to another neuron's
             | cell body or to its dendrite.
             | 
             | Neurons display a dazzling variety in all these parameters:
             | 
             | - In morphology, e.g. they can look like a pine tree
             | http://www.scholarpedia.org/article/Pyramidal_neuron (I
             | really recommend scholarpedia, also this article has a nice
             | animation on how electrical impulses propagate) or like a
             | sea urchin.
             | 
             | - it really matters where the cell gets its impulse from: A
             | neuron stimulated near its cell body will be much more
             | sensitive to the input than being stimulated far away.
             | 
             | - Their response characteristics are wildly varied too.
             | Some give off one large impulse, some a quick burst of
             | impulses. Some are preventing others from giving out
             | impulses from stimulation (inhibitor neurons)
             | 
             | - This whole mess can be modulated with chemical compounds
             | that are released by the body -- some make some neurons
             | more sensitive, some less.
             | 
             | - Also we still discover every year some new mechanism that
             | modulates how they function.
             | 
             | The issue is that this results in such a complex system
             | that a modern PC cant even simulate 1 detailed neuron model
             | realtime (these tools are open source, try them out! for
             | example https://neuron.yale.edu/ ). Now we know that we're
             | simulating things that likely do not matter (e.g. we don't
             | need a neuron model that consist of 10.000+ segments), but
             | we do not know which parts we need to remove to have a
             | faithful simulation. Also we might simply simulate some
             | parts wrong because our knowledge of the subject is not
             | enough.
             | 
             | But on the upside we've reached some great things already,
             | for example we know how our brain calculates from our head
             | and eye position the orientation of the things we're
             | looking at
        
         | postalrat wrote:
         | CPU in kilohertz then megahertz then gigahertz then it stopped.
         | 
         | RAM in kilobytes then megabytes then gigabytes then it stopped.
        
           | manquer wrote:
           | Those are material science and physical limitations.
           | 
           | Number of parameters in a neural network is not really
           | limited that way, doing useful compute with it is a different
           | matter
        
       | savant_penguin wrote:
       | Really cool!
       | 
       | I'd love to see a table comparing the results against the other
       | gigantic models (I know could Google the other results and merge
       | them together but no thanks)
        
       | rustc wrote:
       | Has there been any update on the legality of using this kind of
       | model? Is it ok to just crawl the web, take any content you want,
       | train a model and sell access to the model like
       | OpenAI/GPT-3/GitHub Copilot?
        
         | wyldfire wrote:
         | For the most part, everything that's not barred by law is
         | "legal." Does this use constitute copyright infringement (if it
         | were trained on copyrighted material)? IMO no, but it depends
         | very much on the use of the model. Copilot is especially
         | interesting because instead of being used for simple inference
         | the model is being used to author new works that might aspire
         | to also be copyrighted. Are those new works derivative works?
         | Perhaps. We consider art and science produced by humans to be
         | inspired in part by that which they've been exposed to before.
         | If the model hasn't been overfitted, it should generalize its
         | 'knowledge' sufficiently that it's 'similar' to our
         | intelligence. Humans can commit copyright infringement when
         | they recall and author content so specifically as to be a
         | derived work.
         | 
         | In any case: my opinion matters for naught. The only 'update'
         | you'd get that matters is from a court producing a ruling.
         | Legal journals might chime in but their opinion isn't binding.
         | Theoretically there could be legislation to clarify but that's
         | probably a really, really, really long way off.
         | 
         | Certainly some of the training looks to be content that's not
         | copyrighted or no longer copyrighted, btw.
        
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