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  • Question

  • I have a cluster with only two node. The head node is quadcore while the compute node is using dual core ( headnode also acts as compute node).

    1. However, when i choose P = 2 and Q= 2 in lizard, it uses all the 4 cores in head node instead of 2 in each nodes. How can I configure it so that headnode is running with 2 cores and compute node also running with 2 nodes?

    2. Btw, when i choose P = 2 and Q = 3, it runs on all 6 cores but the speed drops sharply. The network i use is fast ethernet, does the speed limited by fast ethernet?

    Here's the rough result i get:

    2x2 ~~~~> 22 GFLOPS (it uses only headnode as i can see there is no usage of the network in task manager)

    2x3 ~~~~> 10 GLOPS

    Saturday, August 14, 2010 2:28 AM

Answers

  • Lizard works on heterogeneous clusters, so I suggest you to run it first on your compute node, in order to compute the best values for Linpack on a single node.

    I don't think you can thru lizard specify only 2 cores on the HN and 2 cores on the compute node.

    HTH

    Xavier

    Wednesday, September 1, 2010 12:54 PM

All replies

  • Hello,

    There are two possible solutions for your question 1:

    1. Take Head node offline

    2. When start the Lizard, click Advanced button, it will allow you select which nodes you want to run Linpack.

    For your second question, what's the problem size of Linpack? One possible cause I can guess is that there is paging for the Compute node which can seriously drag down the performance. You may need check whether there is paging for Compute Node.

    Thanks,

    James

    Wednesday, September 1, 2010 3:43 AM
  • Lizard works on heterogeneous clusters, so I suggest you to run it first on your compute node, in order to compute the best values for Linpack on a single node.

    I don't think you can thru lizard specify only 2 cores on the HN and 2 cores on the compute node.

    HTH

    Xavier

    Wednesday, September 1, 2010 12:54 PM