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Hi Pete, re: > Any idea on whether the ldm benefits much from threading? I.E. is it > worth pursuing dual core CPUs or is it more just best to have lots of > RAM? This is an interesting question that is not easy to answer simply: We convinced ourselves that having lots (e.g., 4) of CPUs was not useful on a system that both ingesting data from several (exact number is hard to pin down) upstreams and relaying data to lots (> 100) downstreams. Our view was created from performance testing on our old toplevel IDD relay node, thelma.ucar.edu, which was a SunFire 480R. At the same time, we are now testing two SunFire x4200 machines (dual dual core Opteron 2.2 Ghz w/16 GB RAM) in our IDD cluster. This test is very new, so I don't have much to report yet (other than the units appear to be working nicely). > Right now I'm spec'ing out systems with dual single-core opterons, > 2Ghz for the ingest/relay and 2.6 or 2.8 for the decoder. 8 Gb or 16 Gb > on the relay, and 8 Gb on my decoding box. Hmm... so the question of the hour is if a single dual core Opteron is better or worse LDMwise than a box with dual single core Opterons. I wish I knew the answer to this one! > It's looking like I can get something like this and around 5 Tb of > external (scsi) SATAII raid all in a rack for around or a little more > than my 16K. Sweet! > I'm thinking 8 Gb of RAM should be adequate for us for both the > ingest/relay box and our decoder/server box. 8Gb should hold at > least an hours worth of all feeds we're getting. An 8 GB LDM queue will hold between 5300 and 12000 seconds of data for all of the feeds relayed by our cluster: CONDUIT DIFAX FNEXRAD FSL2 GEM HDS IDS|DDPLUS NEXRAD2 NGRID NIMAGE NLDN NNEXRAD UNIWISC > Thanks I'm not sure the info above is what you are looking for, but it is the best I can do. One of our "problems" is we are continuously changing equipment in order to learn the answers to the kind of questions that you are asking _before_ users ask them. Lots of fun :-) Cheers, Tom **************************************************************************** Unidata User Support UCAR Unidata Program (303) 497-8642 P.O. Box 3000 address@hidden Boulder, CO 80307 ---------------------------------------------------------------------------- Unidata HomePage http://www.unidata.ucar.edu **************************************************************************** Ticket Details =================== Ticket ID: QXN-439339 Department: Support Platforms Priority: Normal Status: Closed