iraf.net

For standardized IRAF tasks, are there any benchmark statistics published for various current hardware platforms and configurations?1) I plan to put IRAF on a new PC running Linux. I would like to get a feel beforehand of how much processing power I would need to run standardized tasks in an acceptable time interval. I currently have no experience with IRAF on any platform.2) Can IRAF benefit from a multiple core PC? I could build the PC with a single single-core CPU, a single dual-core CPU or a dual dual-core CPU. Given a dedicated machine, I don't see how IRAF could take advantage of the extra cores. All the CPUs would be AMD 64-bit and cutting edge in terms of operating frequency.3) Is there a Linux distro that is particularly recommended for IRAF? If so, which one and why?Thanks.

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RJ Emery

Robert,You need to quantify terms like 'standardized' and 'acceptable' to get a meaningful answer, but maybe the following will help. We don't generally keep benchmarks due to the infinite number of configurations, but a "standard" benchmark script we've used before creates some dummy images, does basic CCD processing, combines and image and does a median filter of 2k x 2k images; all the standardized things I think you mean. On a dual 3-Ghz linux (RH9) server with 2GB RAM the execution times are roughly:[code:1:0ecc375c1a]
Total execution time = 16.0 seconds
Total time Make 5 imgs Proc 3 imgs Combine 3 imgs Median 1 img
16.0 5.0 3.0 1.0 7.0
[/code:1:0ecc375c1a]This test pretty well covers the CPU- and disk-intensive applications but of course times will vary based on things like your disk speed, size of images, number to process, etc.[quote:0ecc375c1a]
2) Can IRAF benefit from a multiple core PC? I could build the PC with a single single-core CPU, a single dual-core CPU or a dual dual-core CPU. Given a dedicated machine, I don't see how IRAF could take advantage of the extra cores. All the CPUs would be AMD 64-bit and cutting edge in terms of operating frequency.
[/quote:0ecc375c1a]Only in the sense the system in inherently multi-process, i.e. the CL, the task you're running, maybe a graphics kernel etc are all running for one "task". You can run parallel pipelines to use the CPU/core but an individual image won't be split across mutiple cores for processing. You can certainly write a pipeline that keeps a multi-cpu/core machine occupied, but not just by running CCDPROC from the prompt.Note also that IRAF is not (yet) 64-bit compatible so you'll be limited to 2Gb memory and file sizes, and compilation under 64-bit systems can also be tricky. Existing 32-bit binaries will run but keep this in mind if you'll be developing something other than scripts.[quote:0ecc375c1a]
3) Is there a Linux distro that is particularly recommended for IRAF? If so, which one and why? [/quote:0ecc375c1a]The most popular is probably still RedHat Enterprise/Fedora but there is no specific recommendation. Hope this helps.Cheers,
-Mike

[quote:dcac8a8c0c="fitz"]Robert,Note also that IRAF is not (yet) 64-bit compatible so you'll be limited to 2Gb memory and file sizes, and compilation under 64-bit systems can also be tricky. Existing 32-bit binaries will run but keep this in mind if you'll be developing something other than scripts.[/quote:dcac8a8c0c]Fairly certain 32bit OS is limited to 4GB memory. I think the maximum file size is 2GB. There was a limitation of 256MB memory for iraf from using "shared libraries". I think this has been removed ?There are some variables such as MAXWORKSET that affect the memory available to iraf. I really don't know if they actually do anything now.Regards,
--Chris

Mike,I appreciate the response. The figures you gave indicate anything I build will be fast enough for typical IRAF tasks. Thanks.

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RJ Emery