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HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

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Re: HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

#11

Not enough. Because, you know, there happens to be something else that is driven by memory. I'll give you a hint as to what it is: it's comprised of approximately a hundred billion units. (And no, it's not a galaxy.) Divide 160 terabytes by the number I just stated, and you'll find that that you only get 1.6 kilobytes per unit. Not really enough (or at least, too close for comfort). Step up your game, HP! :) But, thi…

Maybe just say what you mean, instead of riddles, as part of contributing to the discussion?

Re: HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

#12

Not enough. Because, you know, there happens to be something else that is driven by memory. I'll give you a hint as to what it is: it's comprised of approximately a hundred billion units. (And no, it's not a galaxy.) Divide 160 terabytes by the number I just stated, and you'll find that that you only get 1.6 kilobytes per unit. Not really enough (or at least, too close for comfort). Step up your game, HP! :) But, thi…

Maybe just say what you mean, instead of riddles, as part of contributing to the discussion?

~100 billions neurons in a human brain I guess. Not sure what 1.6KB per neuron is too close to

Re: HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

#13

Not enough. Because, you know, there happens to be something else that is driven by memory. I'll give you a hint as to what it is: it's comprised of approximately a hundred billion units. (And no, it's not a galaxy.) Divide 160 terabytes by the number I just stated, and you'll find that that you only get 1.6 kilobytes per unit. Not really enough (or at least, too close for comfort). Step up your game, HP! :) But, thi…

Maybe just say what you mean, instead of riddles, as part of contributing to the discussion?

I assume poster is referring to the human brain, but yes, too clever by half and doesn't contribute much to the conversation.

Personally, I'm quite disappointed that this isn't memristor based - not much of an improvement in holding a conscious statefile that disappears when the power goes out.

Re: HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

#14
I am not sure if I should be impressed until they reveal more details.

160 TB over 40 nodes is 4 TB per node, which assuming 512 GB dimms requires only 8 dimms (4 per socket) or with 256 GB dimms 16 dimms (8 per socket).

How fast is the interconnect? 100Gb/s?

So far it sounds like an common high memory HPC cluster unit with really unknown technical parameters.

Re: HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

#15
post #2

> The new prototype has 160 TB of shared memory spread across 40 physical nodes, interconnected using a high-performance fabric protocol. So basically something similar to RDMA scaled to 40 nodes, 4 TB RAM per node.

Underwhelming - you could build the same exact thing with a bunch of white box servers and a pair of Infiniband switches.

Re: HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

#18
post #12

Earlier quoted context omitted.

Maybe just say what you mean, instead of riddles, as part of contributing to the discussion?

~100 billions neurons in a human brain I guess. Not sure what 1.6KB per neuron is too close to

This comment currently has a reply ( http://i.imgur.com/N7BZJfu.png ) which shows why I wanted to leave my original post as a "riddle" rather than coming out and saying it.

The following "crap" is not relevant to anything, only read it if you want the answer to why 1.6 KB is insufficient for a certain science fiction fantasy which will never, not in ten, a hundred, or a thousand years, become relevant any more than magicians will start flying around on brooms. It has nothing to do with anything. Don't get me wrong and think that I think it has relevance to something.

Original version of this comment:

--

Well, it's clear that you could not come even close to perfectly describing the state of a cell and all its connections in 1.6 KB. As just one example, every cell has a different genome[1] which if you encoded it in full would be 700 MB right off the bat. I'm not saying the fact that every neuron has a different genome is relevant to its computational functions, but 1.6 KB is cutting it very close. Let's explore why this is so.

Suppose we simplified and said that each neuron may be connected to n other neurons (we will calculate what n fits in our memory). Addressing 100 billion takes 36 bits. (You need approx. 36 bits to name a number between 1 and 100 billion, i.e. if all you're doing is naming which other neuron it's connected to.). So let's see how many "synapses" the 1.6 KB might be enough to address. -- we are looking at how many connections could be encoded into 1.6 KB.

So 1.6 KB if you did nothing else but as a simplification say that you were referring to another neuron, then 1.6 KB = 1.6 * 1024 * 8 = 13107 bits, divide that by 36 and you get 364 addresses. Suppose you were to then encode each of those addresses with a single byte (an 8-bit brain) representing the strength of that connection, and you are down to only encoding 13107/44 = 297 neural connections with an 8-bit connection value. [EDIT!! As pointed out in a reply, original version of this paragraph contained a math error - I originally divided by 8 after dividing by 36 -- as though each bit of the address needed a connection strength, rather than adding 8 to 36 to get the number of bits needed for each connection and only afterward dividing that into the 1.6 KB]

Okay, so let's see how "297 neural connections" stacks up.

In fact "Each neuron may be connected to up to 10,000 other neurons", but "Each of the neurons has on average 7,000 synaptic connections to other neurons." This means we do not have 8 bits - we do not have even a single bit. (Because 7,000 is more than 297 or even 364).

So you cannot even store the full address of each synaptic connection (the full address of the other neuron it's connected to) let alone a value of the strength of it, or anything else computationally interesting that may be going on chemically. Of course, obviously one neuron will not be directly connected with another far away, for example on the other hemisphere of the brain (meaning you can almost certainly shave nearly 1 bit of addressing off of the 36 bits from the get-go, and likely you need a far smaller address space, if you really look at it.)

But as you can see, however you slice it, you're just cutting it extremely slow. If synaptic connections had even 10 bits of value of some kind than you're way over your budget here.

But as you can see we're close - the numbers just barely don't work.

HP are on the right track - they simply need to step their game up.

[1] recently in the news - https://www.scientificamerican.com/article/scientists-surpri...

EDIT* - thanks for the correction, yes, there was a math error.

Re: HPE unveils The Machine, a single-memory computer with 160 terabytes of memory

#20
post #8

Earlier quoted context omitted.

the article is pretty weak, people have built rdma machines that size before, and there have been architectures that allow for direct memory addressability of that size before. so i have to assume the latter. that seems to be borne out by the little information i can find...addressable persistent memory is clearly a theme. but i haven't found any discussion of what kind of latency hiding mechanisms might be at play a…

The Next Platform has had many articles with bits of detail on HPs Machine. Unfortunately, they don't really have any tagging mechanism, but you can search the phrase "the machine" or look at related articles there. https://www.nextplatform.com/2017/01/09/hpe-powers-machine-a...

Great resource. Based on that, it looks like the fabric has a bandwidth of 600Gb/s (or 1.2Tb/s full duplex).

The interconnect seems to be the real innovation here.

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