I wasn't thinking so much about code efficiency, more "wall plug power" 
efficiency.  The board may consume 250W, but it will take non-zero power to 
support that board, and then the power supply efficiency needs to be taken into 
account.  But I suspect the 1 GFLOP/W was more just an "old" "rounded off" 
number.

Yes... it's very hard work to get to a real 75 GFLOP/Watt, but that is what 
DARPA is all about... High Risk, High Reward.  Somehow, though, I can't see 
building a new fab with smaller feature sizes for the paltry sum of 20M.  More 
like they'll do some architecture studies, a pile o'modeling (if we DID invest 
$1B in a new fab, here's what you might be able to do), and do a bunch of work 
on things like failure tolerant architectures (if you have a sea of processors, 
and X% are dead at any given time, how do you write software to run on that sea)

I wonder what Nvidia chips are used in Audis and BMWs?  The video display, 
perhaps: there's a nifty 3D rendered view of the GPS mapping info in the new 
BMWs?  I don't see a real need for that kind of horsepower in an Engine Control 
Unit.  Maybe in a smart cruise control that does station keeping, or in a 
collision avoidance system.  Actually, I don't really see Nvidia being in the 
"safety critical" space at all.




Jim Lux


-----Original Message-----
From: beowulf-boun...@beowulf.org [mailto:beowulf-boun...@beowulf.org] On 
Behalf Of Vincent Diepeveen
Sent: Monday, December 17, 2012 10:02 AM
To: Lux, Jim (337C)
Cc: Beowulf@beowulf.org
Subject: Re: [Beowulf] DARPA issues 20 MUSD grant to nVidia to go from 1 
GFLOPS/Watt to 75 GFLOPS/Watt

On Dec 17, 2012, at 6:27 PM, Lux, Jim (337C) wrote:

> That could be a notional 1 GFLOP/Watt in a fielded system.

Even linpack is 70% - 80% efficient on this so should get out oh let's use a 
conservative 4.5 flops/watt effectively at codes.





Note that (to my big surprise) it seems to be the case that the gpu's are 
effectively getting higher efficiency than Xeon Phi here.

> The original documents for PERFECT are probably a year or two old by 
> now.. but what DARPA is looking for is a nearly 2 order of magnitude 
> improvement...  Whether they started at 1 or 1.4 or 6 really doesn't 
> make much difference to what they're looking for.
>

Yeah well that 2 orders of a magnitude is just 1 order of a magnitude if we 
start at 6.

6 ==> 75 = factor 12

They speak about 7 nm technology in the accompanying document. That's a very 
conservative estimate, obviously in theory even with todays 2 dimensional way 
of building (not to mention when things really get 3d), we speak of a 
difference in theory of:

(28 / 7) ^ 2 = 4^2 = 16

Given enough time, engineers will get that factor 16 easily out of transition 
over the years from 28/32 nm to 7 nm.
Note that 7nm is still far beyond the horizon.

However if they would have needed to improve current design factor 75 moving 
from 28/32 nm they use today to 7 nm, that would be a complicated bet.

> In any case, it's a long way from a manufacturer's cut sheet to a 
> system installed in a tank bouncing through the woods..
>
>
> Jim Lux
>
> -----Original Message-----
> From: beowulf-boun...@beowulf.org [mailto:beowulf- 
> boun...@beowulf.org] On Behalf Of Vincent Diepeveen
> Sent: Monday, December 17, 2012 5:50 AM
> To: Eugen Leitl
> Cc: Beowulf@beowulf.org; i...@postbiota.org
> Subject: Re: [Beowulf] DARPA issues 20 MUSD grant to nVidia to go from 
> 1 GFLOPS/Watt to 75 GFLOPS/Watt
>
> "todays 1 gflop/watt" ?
>
> The K20X delivers 1.4 Tflop nearly.
> If i google it's 235 watt TDP.
>
> 1.4 Tflop / 235 =  6 gflops/watt
>
> On Dec 17, 2012, at 2:21 PM, Eugen Leitl wrote:
>
>>
>> http://www.networkworld.com/community/blog/darpa-awards-20m-nvidia-
>> stretch-achilles-heel-advanced-computing-power
>>
>>
>

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