[Beowulf] [gorelsky@stanford.edu: CCL:dual-core Opteron 275performance]

[Alan Louis Scheinine]

Jakob Oestergaard wrote:
  > Guys, the results are very interesting - it would be very interesting to
  > know, too, which kernels you have been running on.
  > ... I'm pretty sure at least 2.6.12 had NUMA/dual-core fixes in it.

In all cases, 4 MPI processes on a machine with 4 cores (two dual-core CPUs).

Meteorology program 1, "bolam"    CPU time, real time (in seconds)
       Linux kernel 2.6.9-11.ELsmp     122        128
       Linux kernel 2.6.12.2            64         77

Meteorology program 2, "non-hydrostatic"
       Linux kernel 2.6.9-11.ELsmp     598        544
       Linux kernel 2.6.12.2           430        476

The new information is the kernel 2.6.12.2 that I installed today.
Yes, the new kernel helps quite a bit.

-- Alan

  Centro di Ricerca, Sviluppo e Studi Superiori in Sardegna
  Center for Advanced Studies, Research, and Development in Sardinia

  Postal Address:               |  Physical Address for FedEx, UPS, DHL:
  ---------------               |  -------------------------------------
  Alan Scheinine                |  Alan Scheinine
  c/o CRS4                      |  c/o CRS4
  C.P. n. 25                    |  Loc. Pixina Manna Edificio 1
  09010 Pula (Cagliari), Italy  |  09010 Pula (Cagliari), Italy

  Email: scheinin at crs4.it

  Phone: 070 9250 238  [+39 070 9250 238]
  Fax:   070 9250 216 or 220  [+39 070 9250 216 or +39 070 9250 220]
  Operator at reception: 070 9250 1  [+39 070 9250 1]
  Mobile phone: 347 7990472  [+39 347 7990472]