uninterruptible sleep in the calculations

Just Got Here	8:43:17 PM PST - Mon, Dec 16th 2013 Dear all, recently i installed the NWCHEM 6.3 on my PC (CPU: i7-3770K, 32G RAM, 2T disk, OS: UBUNTU 12.04 (64 bit), Openmpi:1.6.5, Ifort & Icc: 13.1.3 ). When i run "top" i found the process of NWCHEM are either R or D, for the later, GOOGLE says "Processes in a "D" or uninterruptible sleep state are usually waiting on I/O. " i also found the "ubinterruptible sleep" on my clusters ( RHEL 5.7 and CENT OS 6.3.) What the bottleneck, should i change the SATA disk as SAS or SSD? And how to avoid it for the clusters, should i add an I/O cluster? Thanks for your response.

Forum Vet	10:29:38 AM PST - Tue, Dec 17th 2013 Skipper How many NWChem parallel processes are you using on your CPUs? If you use more than a couple, I would switch to algorithms that make little use of I/O (e.g. direct SCF)

Just Got Here	7:50:14 PM PST - Wed, Dec 18th 2013 Dear Edoapra, Thnaks for your comments, it works when i use the "direct SCF".

Forum >> NWChem's corner >> Running NWChem