The Group's second Linux cluster, collectively known as Titania, consisted of 100 Athlon systems divided into five sub-clusters. It was designed in 2000-01, and remained in service from April 2001 to June 2003. After retirement, its nodes were used as local desktops (until 2006), donated to help build a Chemistry cluster, and used to build small test clusters, utilized for a series of cluster-building workshops.

System Specifications

  • 1100 MHz AMD Athlon CPU (titania, ariel), 1333 MHz (oberon, umbriel)
  • Asus A7V Motherboard (titania, puck), Asus A7A266 Motherboard (oberon, umbriel, portia)
  • 256 MB CAS2 SDRAM (mix of ECC and non ECC)
  • 20GB 7200rpm Western Digital hard drive
  • 100Mbps Ethernet Cards - mix of:
    • Intel EtherExpress (two on root node)
    • 3Com 3C905B (eventually replaced with more Intel cards for homogeneity)
  • Floppy and CD-ROM drives
  • Scyld Linux
  • Built by Champaign Computer

titania, ariel, oberon, umbriel

titania and ariel each consisted of 16 1100MHz Athlon CPUs with 256 MB of memory each. oberon and umbriel consisted of 32 1333 MHz systems.

puck, portia

puck and portia were test clusters: puck consisted of two 1100MHz Athlons, portia of two 1333MHz systems.

Each cluster was controlled as a single root node, which is controlled much like a standard Linux box. Computations were divided up and transferred to the rest of the cluster by a single front end machine. The other machines had no keyboard, mouse, or monitor; they only connect via the network. All of the machines were connected through four 3Com SuperStack III 3300TM 24-port switches, each with a Gigabit uplink and a matrix port for attaching additional switches, and two 3300 III 3300MM, which have three matrix ports to connect the other switches.


Using the molecular dynamics code NAMD we achieved these speedups on a 92,000 atom system on our clusters (as of December 2001):

CPUs 1333 MHz Athlon
Sec/Step Speed-Up Efficiency
1 10.54 1 100%
2 5.45 1.93 96.7%
4 2.83 3.72 93.1%
8 1.52 6.93 86.7%
16 0.83 12.70 79.4%
32 0.47 22.43 70.1%

Breakdown of Costs (at time of purchase)

Count Unit Cost Total   Description
1100 MHz PCs 36 $1,039.00 $37,404.00   4 spares
1333 MHz PCs 70 $975.85 $68,309.50   6 spares
Add. Network Cards 4 $50.00 $200.00
Ethernet Switches 6 $1,403.62 $8,421.72 4x 3Com 3300TM
2x 3Com 3300MM
Shelves, Cables, Etc ~$ 1,200.00
Total $115,535.22