AMD Bulldozer CPU Architecture Overview

Architecture per core:

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Inhibit Annoying Message of the Day in Ubuntu

I find the motd annoying when you log in to a Ubuntu server machine. To get rid of this I do the following as root:

cd /etc/update-motd.d
mkdir klmDisabled
mv ??-* klmDisabled

Unfortunately, whenever the packages update-manager-core, landscape-common, base-files, update-notifier-common change, they might put their junk again into above directory. I reapply above move to get silence again.

Today I noticed, when I fired up my Ubuntu 12.04 server running within VirtualBox, that these messages may consume so much CPU that they are postponed.

Running CPU/GPU Intensive Jobs on Titan Supercomputer

There is a an INCITE program (HPC Call for Proposals), where one can apply for CPU/GPU intensive jobs, the link is INCITE.

From the FAQ: The INCITE program is open to US- and non-US-based researchers and research organizations needing large allocations of computer time, supporting resources, and data storage to pursue transformational advances in science and engineering.

The machines in question: Mira and Titan.

CPU Usage Time Is Dependant on Load

I wanted to write a short benchmark for my son to demonstrate that the AMD Bulldozer 8 core CPU is better than a 6 core CPU from AMD when computing with integers. So I wrote a short C program to compute a recurrence relation using integers only, see C code below. When I ran this program on one core, then two cores, then three cores, and so on, I was a little bit surprised to see that the CPU usage time grew. Indeed, it grew quite significantly: from 20 to 60% up! Once all cores of the CPU are used then the CPU usage does no longer increase. In this case it does seem to have reached its equilibrium.

The AMD CPU is a FX 8120, 3.1GHz. For comparison I used an Intel i7-2640, 2.8GHz, 4 core CPU.

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