On 11/28/2012 11:27 AM, Vincent Diepeveen wrote: > > On Nov 28, 2012, at 4:30 PM, Prentice Bisbal wrote: > >> >> On 11/27/2012 07:32 PM, Vincent Diepeveen wrote: >>> >>> On Nov 28, 2012, at 12:17 AM, Prentice Bisbal wrote: >>> >>>> >>>> On 11/27/2012 03:37 PM, Douglas Eadline wrote: >>>>> >>>>>> My interest in Arm has been the flip side of balancing flops to >>>>>> network >>>>>> bandwidth. A standard dual socket (AMD or Intel) can trivially >>>>>> saturate >>>>>> GigE. One option for improving the flops/network balance is to add >>>>>> network bandwidth with Infiniband. Another is a slower, cheaper, >>>>>> cooler >>>>>> CPU and GigE. >>>>>> >>>>> applause. >>>> >>>> I applaud that applause. >>>> >>>> What Bill has just described is known as an "Amdahl-balanced system", >>>> and is the design philosophy between the IBM Blue Genes and also >>>> SiCortex. In my opinion, this is the future of HPC. Use lower power, >>>> slower processors, and then try to improve network performance to >>>> reduce >>>> the cost of scaling out. Essentially, you want the processors to be >>>> *just* fast enough to keep ahead of the networking and memory, but no >>>> faster to optimize energy savings. >>> >>> For HPC the winning concept seems to be increasing corecount at >>> manycores. >>> >>> We also see how bluegene couldn't keep its concept - it's having >>> what is it 18+ cores >>> now or so? >> >> It's not 18+. It's exactly 18 cores. And only 16 are used for >> computation. One is used for operating system overhead, and the other >> is a spare. >> This is exactly in keeping with the Blue Gene Concept, which is using >> low-power processors to conserve energy connected to highly-optimized >> interconnects to create a more balanced system. 'Low-power' and 'low >> core-count' are not the same thing. >> > > > Here is what wiki says on the original concept: "Trading the speed of > processors for lower power consumption. Blue Gene/L used low frequency > and low power embedded PowerPC cores with floating point > accelerators.While the performance of each chip was relatively low, > the system could achieve better performance to energy ratio, for > applications that could use larger numbers of nodes." > > It's obvious this won't be the case in the future. > > It means the future is big fat manycores eating a ton of power for > each CPU. > > Arguing then that each core is low power is not relevant - it's not > the original concept of the CPU being low power and embedded > as you can see from the wikisayings.
*Sigh*... Many lower-powered cores can still equal a low-powered complete processors. _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
