Hardware

Secure access to remote systems

Author: Adrian Jackson
Posted: 5 Sep 2016 | 10:35

06/09/16: As pointed out by my colleague Stephen in the comments after this post, the way to solve most of these issues is to tunnel the key authentication and therefore bypass the need to have private keys anywhere but on my local machine.  I'm always learning :)

Password vs key

Having to remember a range of passwords for systems that I don't use regularly is hard. 

You can use a password manager, but that only helps if I'm only ever trying to log in from my own laptop. If I have to log in from someone else's machine for any reason then I'd need to know the password.

MPI performance on KNL

Author: Adrian Jackson
Posted: 30 Aug 2016 | 12:22

Knights Landing MPI performance

Following on from our recent post on early experiences with KNL performance, we have been looking at MPI performance on Intel's latest many-core processor.

MPI ping-pong latency on KNC and IvyBridge
Figure 1

The MPI performance on the first generation of Xeon Phi processor (KNC) was one of the reasons that some of the applications we ported to KNC had poor performance.  Figures 1 and 2 show the latency and bandwidth of an MPI ping-pong benchmark running on a single KNC and on a 2x8-core IvyBridge node.

Early experiences with KNL

Author: Adrian Jackson
Posted: 29 Jul 2016 | 16:45

Initial experiences on early KNL

Updated 1st August 2016 to add a sentence describing the MPI configurations of the benchmarks run.
Updated 30th August 2016 to add CASTEP performance numbers on Broadwell with some discussion

EPCC was lucky enough to be allowed access to Intel's early KNL (Knights Landing, Intel's new Xeon Phi processor) cluster, through our IPCC project.  KNL Processor Die

KNL is a many-core processor, successor to the KNC, that has up to 72 cores, each of which can run 4 threads, and 16 GB of high bandwidth memory stacked directly on to the chip.

Creating a safe haven for health data

Author: Donald Scobbie
Posted: 6 Jul 2016 | 14:36

Safe havens allow data from electronic records to be used to support research when it is not practicable to obtain individual patient consent while protecting patient identity and privacy. EPCC is now the operator of the new NHS National Services Scotland (NSS) national safe haven in collaboration with the Farr Institute of Health Informatics Research which provides the infrastructure. 

Latest Top500 list, looking beyond the number 1

Author: Adrian Jackson
Posted: 21 Jun 2016 | 17:13

There's been a lot of discussion about the latest Top500 list, released this week at ISC16.  Most of the interest has been in the whopping new Chinese system, Sunway TaihuLight, which has come in at number 1 on the list with a massive 93 PFlop/s rpeak Linpack performance, and 125 PFlop/s rmax theoretical peak performance (3 times bigger than the previous number 1 system).Top500

Whilst this is a very interesting system, and much bigger than is currently planned elsewhere, it's not unknown for very large systems to come in and dominate the list like this.  Back in 2002, the Japanese Earth Simulator system became the number 1 machine with an rpeak of ~5x that of the previous number 1 system, and it stayed as the top machine for a number of years.

Investigating power use in parallel computing

Author: Mirren White
Posted: 3 Jun 2016 | 16:09

The Adept project has been working hard for over two years to further understanding of how power is used in parallel software and hardware, and we are now on the finishing straight. 

It's a good time to take stock of our achievements and reflect on how to focus our efforts in the final phase. Also to consider life after the project ends: how do we want to exploit the technologies we have developed and the knowledge we have gained? How do we ensure a lasting legacy for Adept?

HPC hardware in 2016 and beyond

Author: Adrian Jackson
Posted: 19 Apr 2016 | 23:14

Anyone taking more than a passing interest in HPC hardware recently will have noticed that there are a number of reasonably significant trends coming to fruition in 2016. Of particular interest to me are on-package memory, integrated functionality, and new processor competitors.  Intel Xeon Phi (KNL) Die

On-package memory, memory that is directly attached to the processor, has been promised for a number of years now. The first product of this type I can remember was Micron's Hybrid Memory Cube around 2010/2011, but it's taken a few years for the hardware to become mature enough (or technically feasible and cheap enough) to make it to mass market chips. We now have it in the form of MCDRAM for Intel's upcoming Xeon Phi processor (Knights Landing), and as HBM2 on Nvidia's recently announced P100 GPU.

What's inside the box? Building computers from scratch

Author: Iain Bethune
Posted: 28 Sep 2015 | 13:28

Last weekend, a team of us attended Bang Goes The Borders, a regional science festival hosted by St Mary's school in Melrose.

This was the fourth year we've been there, and as usual there were around 1000 school kids and their families keen to get their hands on all kinds of science- and technology-based activities.

Although our "dinoracer" has been a big favourite for the last few years, this time we took along two completely new activities: the Supercomputing App and the Build-a-PC Junkyard Challenge - which I'd like to tell you about...

War in the coding world

Author: Adrian Jackson
Posted: 11 Sep 2015 | 13:41

It's not often that the internecine rivalries of the HPC research and development community spill over into the public arena. However, a video recently posted on YouTube (and the associated comments), ostensibly a light-hearted advert for a SC15 tutorial on heterogenous programming, shows how real and deep these rivalries can be.

HPCG: benchmarking supercomputers

Author: Adrian Jackson
Posted: 30 Jul 2015 | 14:40

HPCG

The LINPACK library (often known as HPL) has been used to benchmark large-scale computers for over 20 years, with the results being published in the Top500 list. But does it accurately reflect the performance of real applications?

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