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Number crunching :
What are acceptable acronymes/terminology for the S@h main forum?
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Stubbles Send message Joined: 29 Nov 99 Posts: 358 Credit: 5,909,255 RAC: 0 |
...as opposed to the S@h Beta forum. The reason I'm asking is because I was corrected in a post I made in another thread...and I didn't want to start a totally unrelated tangent. Fyi, to me this is also part of "The big picture" that I asked others to comment on. So to put all in context, the reply to one of my lines (also included) was as follows: - the nonVLARs shorties: <1mins use about 75-90% of core From what I understand from my 3 months in this forum,
VLAR stands for: Very Low Actual Range. Since that terminology and those acronyms are pretty meaningless to most SETIzens in this forum (who are not also in the S@h Beta forum), I choose to use terminology that doesn't require guru knowledge. |
OzzFan Send message Joined: 9 Apr 02 Posts: 15691 Credit: 84,761,841 RAC: 28 |
Very High Angle Range Very Low Angle Range The angle indicates the satellite's relative position to the night sky. A mnemonic Ageless told to me years ago was to remember: Very High [Speed] Angle Range Very [S]Low Angle Range This is in terms of host fast they process. In other words, low angle ranges process much slower because they tend to pickup nearby terrestrial noise (e.g. military radar) and thus require a lot of blanking. High angle ranges are relatively cleaner and thus can process faster without the need for blanking. Someone will correct me if I'm wrong on the angle ranges, but I know I'm right on the acronyms. |
Shaggie76 Send message Joined: 9 Oct 09 Posts: 282 Credit: 271,858,118 RAC: 196 |
I've also been wondering what SoG and GUPPI mean (I've seen SaH as well and I assume it means S@H). |
Zalster Send message Joined: 27 May 99 Posts: 5517 Credit: 528,817,460 RAC: 242 |
I've also been wondering what SoG and GUPPI mean (I've seen SaH as well and I assume it means S@H). SoG means Signals on GPU (meaning most of the data is crunched on the GPU rather than switching back and forth to the CPU) GUPPI blc3_2bit_guppi_57451_19304_HIP62472_0003 |
AMDave Send message Joined: 9 Mar 01 Posts: 234 Credit: 11,671,730 RAC: 0 |
I've also been wondering what SoG and GUPPI mean (I've seen SaH as well and I assume it means S@H). SoGÂ Â Â Â >Â Â Message 56479 GUPPIÂ Â >Â Â Message 1778453 |
Shaggie76 Send message Joined: 9 Oct 09 Posts: 282 Credit: 271,858,118 RAC: 196 |
Thank you! Need to sticky a post with a glossary |
AMDave Send message Joined: 9 Mar 01 Posts: 234 Credit: 11,671,730 RAC: 0 |
Thank you! Need to sticky a post with a glossary Ask and ye shall receive:Â Â BOINC FAQ Service Scroll to section 4. |
AMDave Send message Joined: 9 Mar 01 Posts: 234 Credit: 11,671,730 RAC: 0 |
Thank you! Need to sticky a post with a glossary ... and this ... From SETI'S home page, click "About".  Next page, click "Glossary of terms." |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
I'm not sure if the VHAR & VLAR terms came from the staff or if they were terms we started using first to refer to the angle range of specific tasks. Either way the terms refer to the angle range of the work we are doing. The project has currently defined VLAR(Very Low Angle Range) tasks to be a task with angle range of <0.12, it was once <0.013, & adds to .vlar the workunit/task names. VHAR(Very High Angle Range) tasks, aka "shorties", may not have a strict definition by the project, but an angle range >1.0 is often referred to as a VHAR. I believe one of the lunatics has generated a time/AR chart several years ago. Which showed a pretty clear change in runtime based on the AR. It more or less looking something like this: \ --- \With time going up and AR going from low to high. Everything between a VLAR & VHAR is often referred to as mid-range. I think we should be calling them MAR myself. Then when we use the plural form it would be MARs. However saying "you have a bunch of MARs tasks" might be confusing to some. As they might thing we are looking for radio signals from the planet Mars instead of from distance stars. I believe the AR that the classic project used, when they were paying for the telescope time, was ~0.42. So 0.40-0.44 AR tasks I normally refer to as "normal AR". Which are ideally what you want to use for baseline comparisons, but with the GBT data they will likely be rare. VHARs >1.0 (aka "Shorties") Mid-range (0.12 - 0.99) (aka "MARs"?) VLARs <0.12 (aka "OMG Why are these SO SLOW!") SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
Yep. Here, for example:http://lunatics.kwsn.info/index.php/topic,1806.0.html SETI apps news We're not gonna fight them. We're gonna transcend them. |
Richard Haselgrove Send message Joined: 4 Jul 99 Posts: 14649 Credit: 200,643,578 RAC: 874 |
And a lot more in Estimates and Deadlines revisited. That thread dates from before general purpose GPUs had been invented, and from a much simpler SETI search (about v6, I think). Unfortunately, most of my graphs have been deleted by a hosting company that got greedy (I still have the originals), but Joe's post number 698744 gives a clear idea of the relative frequency of tasks (Arecibo only) at different Angle Ranges. Technically, VLAR was used to denote AR 0.05 and below, and VHAR for AR 1.1275 and above. When GPUs came along, we extended VLAR to a somewhat arbitrary AR 0.12 |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
And a lot more in Estimates and Deadlines revisited. That thread dates from before general purpose GPUs had been invented, and from a much simpler SETI search (about v6, I think). Interesting that midAR took more time than VLAR on Joe's hardware those times. Picture quite changed in this area now. SETI apps news We're not gonna fight them. We're gonna transcend them. |
Richard Haselgrove Send message Joined: 4 Jul 99 Posts: 14649 Credit: 200,643,578 RAC: 874 |
And a lot more in Estimates and Deadlines revisited. That thread dates from before general purpose GPUs had been invented, and from a much simpler SETI search (about v6, I think). I think it's unchanged for CPUs... Edit - or maybe not. Valid tasks for computer 7118033. That's with your AVX/64 - I forget (*) what CPU apps we were using in early 2008. Interesting: I wonder whether the general signal finding at mid-AR has become more optimal, or something has slowed down (relatively speaking) the pulsefinding at VLAR? * (but I could probably look it up) |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
For our opt builds (and i measured SSSE3 mostly with Q9450 host) VLAR always was harder. And this inspite of Alex Kan's and Ko swarm of pulsefind codelets in CPU code. Maybe worth to build more modern, v8-based, curves for CPU-only build opt vs stock. We know that opt in whole faster but this still allows some inefficiencies in some parts... [though we usually test versus PG set and there is separate VLAR and VLAR is mostly Pulsefind]... Well, maybe worth to test opt vs stock CPU on set of PulseFind test modules and FFT sizes test modules Joe supplied to us some time ago.. To get more precise picture if opt faster always or there are some hidden inefficiency for some of WUs. SETI apps news We're not gonna fight them. We're gonna transcend them. |
Richard Haselgrove Send message Joined: 4 Jul 99 Posts: 14649 Credit: 200,643,578 RAC: 874 |
Well, with the renewed interest in multicore (and multi-CPU) Xeons to handle the preponderance of guppi VLARs, devoting more energy to fine-tuning the CPU apps would certainly be worthwhile - they've really been allowed to drop down the precedence list since the abandonment of IPP and Joe's departure from the boards. But I don't think it's necessary, specifically, to revisit the deadline curve - the main purpose of that exercise was to prove to Eric that the absurd 109-day deadline at AR 0.226 was completely unnecessary and simply clogged the database. Now that we control the database size with task limits, deadlines are hardly relevant any more. |
AMDave Send message Joined: 9 Mar 01 Posts: 234 Credit: 11,671,730 RAC: 0 |
VHARs >1.0 (aka "Shorties") @HAL9000
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Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
Such curves Joe presented there can be used for another purposes and I spoke about them, not about deadlines. SETI apps news We're not gonna fight them. We're gonna transcend them. |
Richard Haselgrove Send message Joined: 4 Jul 99 Posts: 14649 Credit: 200,643,578 RAC: 874 |
Another complication: The numbers we've been discussing recently (Angle Range in degrees) are actually functions of the 'beam width' of the telescope. For a moment, reverse the direction, and imagine the telescope as a giant searchlight: a very bright lamp at the focal point, and a beam of light reflected from the bowl and reaching out into the sky. Because Arecibo has a larger reflecting surface than GBT, it can (in theory, assuming perfect optics) send out a narrower beam. Going back to its normal function as a telescope: our receiver sits at the same focal point as the imaginary lamp, and is most sensitive to sources in the area occupied by the imaginary searchlight beam. Because the GBT beam/sensitive region is larger than the Arecibo beam, the VLAR/mid-AR/VHAR transition points will be higher for GBT 'guppi' tasks than for Arecibo tasks. |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
Agree, there will be differencies. So far we had very little non-VLAR GBT data AFAIK. But what I tried to say is if there is some place in processing chain where stock code faster than Lunatics one building comparative opt + stock performance/AR curves (separately Arecibo/ GBT to account for your warning) could reveal that places. SETI apps news We're not gonna fight them. We're gonna transcend them. |
HAL9000 Send message Joined: 11 Sep 99 Posts: 6534 Credit: 196,805,888 RAC: 57 |
VHARs >1.0 (aka "Shorties") For my newer post in this thread I was working from memory instead of using my reference sheet. My main goal was showing that the acronyms referred to specific numbers. My older post has a more accurate value for VHARs. As did the post Richard made in this thread with the specif AR value that had been found previously. Looking at the original graph. I want to run something similar with the current apps/data & see how they compare to the previous findings. Currently I don't have the time to do that. Does VMAR stand for Very Mid Angle Range? I would think a very mid AR would be a normal AR. We really we don't need to define everything with a name. I had found it amusing since I noticed an acronym for Mid Angle Range could spell mars when plural. SETI@home classic workunits: 93,865 CPU time: 863,447 hours Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[ |
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