Posts by Chris L

1) Message boards : Number crunching : Upload failures (Message 60474) Posted 27 Jun 2019 by Chris L Post: Sorry for being dense... Actions to be taken are 1) Suspend all CPDN tasks -is that compute, and/or all network activity? 2) Any advice for extending upload time limits - is the old 14 day thread still applicable?
2) Message boards : Cafe CPDN : Any chance of an Xmas message form the CPDN team... (Message 59237) Posted 25 Dec 2018 by Chris L Post: A brief summary of CPDN's work in 2018 would be appreciated...!
3) Questions and Answers : Windows : Visual Fortran Run-Time Error (Message 22540) Posted 1 May 2006 by Chris L Post: I\'ve had this occur. I changed to BOINC 5.4.6 and a dead model came back to life, and no more erro messages.
4) Questions and Answers : Wish list : RAM cache of open climate modelling files (Message 19447) Posted 19 Jan 2006 by Chris L Post: Has anyone cached the open modelling files to RAM? OK, one would need a lot of RAM, but it would be much faster than all these HDD reads.
5) Questions and Answers : Preferences : Optimising BOINC on AMD 2800+ (Message 15599) Posted 1 Sep 2005 by Chris L Post: > Both, as well as memory latency being important, especially for AMD. It's > really hard to say one is more important than the other, and it depends on how > much you change one or the other. > > An example from AMD64. I have AMD64 3400+ and 3800+ CPUs, each are running at > 2.4 GHz with 512 KB L2 cache. Both run on Nvidia Nforce3 chipset > motherboards. The latency of the memory modules on each PC are the same. The > 3800+ has a dual channel memory controller and has significantly greater > memory bandwidth because of it. The 3800+ does about 1.7 sec/TS while the > 3400+ does about 1.9-1.95 sec/TS. > > Why, are you thinking of upgrading your PC? > I am indeed thinking of upgrading my PC. The information on how the climate modelling uses resources is then obviously relevant, and more subtly also helps to optimise my current PC. So I have optimised memory bandwidth 'efficiency' to >90%, with only a very slight decrease in cycle time from 2.88 to 2.75 s/TS. One reads all sorts of benchmarks on CPUs and memory, but only rarely on complete systems for scientific applications, and certainly none for this one in particular. Also an issue here, with these very long computations, is (accumulated) computer errors; this may even be more important than pure speed. So, would ECC DRAM be an improvement for the project?
6) Questions and Answers : Preferences : Optimising BOINC on AMD 2800+ (Message 15582) Posted 31 Aug 2005 by Chris L Post: What factors most affect computation speed - FPU performance, memory bandwidth ..??