- 8x Intel Xeon CPUs (E5-2676 v3 @ 2.4GHz)
- 60GB of Memory
- 6x 2TB HDDs
$ sudo mdadm --create --verbose /dev/md0 --level=stripe --raid-devices=6 /dev/xvd? $ sudo mkfs.xfs /dev/md0 $ df -h /mnt /dev/md0 11T 34M 11T 1% /mnt
$ sudo hdparm -tT /dev/md0 Timing cached reads: 21126 MB in 2.00 seconds = 10576.60 MB/sec Timing buffered disk reads: 1784 MB in 3.00 seconds = 593.88 MB/sec
Program Version: 0.6.8 Build 9461 (Linux - x64 AVX2 ~ Airi) Constant: Golden Ratio Algorithm: Newton's Method Decimal Digits: 2,000,000,000,000 Hexadecimal Digits: 1,660,964,047,444 Threading Mode: Thread Spawn (1 Thread/Task) ? / 8 Computation Mode: Swap Mode Working Memory: 61,342,174,048 bytes ( 57.1 GiB ) Logical Disk Usage: 8,851,913,469,608 bytes ( 8.05 TiB )
Start Date: Thu Jul 16 03:54:11 2015 End Date: Sun Jul 19 11:14:52 2015 Computation Time: 221548.583 seconds Total Time: 285640.965 seconds CPU Utilization: 315.469 % Multi-core Efficiency: 39.434 % Last Digits: 5027026274 0209627284 1999836114 2950866539 8538613661 : 1,999,999,999,950 2578388470 9290671113 7339871816 2353911433 7831736127 : 2,000,000,000,000
Now, let's talk about the economics here, which I think are the most interesting part of this post.
Look at the above chart of records, which are published on the y-cruncher page, the vast majority of those have been calculated on physical PCs -- most of them seem to be gaming PCs running Windows.
What's different about my approach is that I used Linux in the Cloud -- specifically Ubuntu in AWS. I paid hourly (actually, my employer, Canonical, reimbursed me for that expense, thanks!) It took right at 160 hours to run the initial calculation (79 hours) as well as the verification calculation (81 hours), at the current rate of $1.38/hour for a d2.2xlarge, which is a grand total of $220!
$220 is a small fraction of the cost of 6x 2TB disks, 60 GB of memory, or 8 Xeon cores, not to mention the electricity and cooling required to run a system of this size (~750W) for 160 hours.
If we say the first first trillion digits were already known from the previous record, that comes out to approximately 4.5 billion record-digits per dollar, and 12.5 billion record-digits per hour!
Hopefully you find this as fascinating as I!