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Number crunching :
again less credits?
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Author | Message |
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W-K 666 Send message Joined: 18 May 99 Posts: 19401 Credit: 40,757,560 RAC: 67 |
IT'S ALL A CONSPIRACY ! The last thing you want is more CUDA cards if you want the MB credits to return to the 'correct', (cpu only) level. AP _V5 credits have remained steady, within 3% since its introduction. But over a slightly longer period since the introduction of CUDA MB credits have fallen by ~15%. Now I'm not saying CUDA is a bad idea. I actually think it is a good idea, but it has been let down by BOINC. The BOINC devs probably knew CUDA apps were on their way months before they appeared and yet over 6 months after the Seti CUDA app was released the BOINC client still has problems. The problems, as far as credits are concerned, total inability to report gpu time and differing Flops count for same task completed on gpu compared to cpu. Add in the other BOINC problems of suspended tasks and inability to d/load correct number of tasks for cache size, reports of overheating and failure of CUDA cards, and you soon realise why, unless you have the time to observe and micro-manage Seti/BOINC, it is probably not the time introduce more CUDA cards. We do have three CUDA capably cards, one in the E6600 and two in the Q9450 computers but they are my sons gaming machines. Disabling the gaming function for any reason is not an option. Youngest son is about 6 inches taller than me. |
Betting Slip Send message Joined: 25 Jul 00 Posts: 89 Credit: 716,008 RAC: 0 |
Disabling the gaming function for any reason is not an option. Youngest son is about 6 inches taller than me. Seems like a good call :) |
Jord Send message Joined: 9 Jun 99 Posts: 15184 Credit: 4,362,181 RAC: 3 |
Putting the cat among the pigeons... Once upon a time, some guys at Berkeley came up with this BOINC thingy, and they thought it'd be good if they could bring in all the other projects and issue credit for work done, and have the credit be comparable between projects. This was never formally written down anywhere, it was only informally asked that projects followed the same 'rules for giving out credit'. It's still not a demand, just a request. So... it could be that you get 50 credits for Seti, but 33,333 for a whole other project, just because they not necessarily want to 'play ball'. Still pigeons alive? More cats in then. Here's what Rom Walton had to say about it when I asked about the magic credits: Rom Walton wrote: On a technical level they can hand out whatever amount of credit they want. |
EPG Send message Joined: 3 Apr 99 Posts: 110 Credit: 10,416,543 RAC: 0 |
You have to remember to David vs. Goliath and use the exclusive_app cc_config option :D |
Larry256 Send message Joined: 11 Nov 05 Posts: 25 Credit: 5,715,079 RAC: 8 |
Putting the cat among the pigeons... That just means that if they can't preswade the projects,They'll will preswade the stat sights.Thats the collectives way. Edit 1 time |
Larry256 Send message Joined: 11 Nov 05 Posts: 25 Credit: 5,715,079 RAC: 8 |
SO if my HAL9000 benchmarked 10,000,000,000 double-precision MIPS Whetstone benchmark,and 10,000,000,000 VAX MIPS based on the Dhrystone benchmark. Would you have no problem with the insane amount of credit that it would do in a day? Or would you want it to get the mean of all computers at that time? Then years later when a new computer came out and was twice a fast has HAL would I get less because HAL is behind the mean? |
1mp0£173 Send message Joined: 3 Apr 99 Posts: 8423 Credit: 356,897 RAC: 0 |
Larry, You're repeatedly missing one very important point. The credit adjustment finds the median from the sample and calculates the credit based on "benchmark * time" and slowly adjusts the FLOPs-based score to match what "benchmark * time" would have given. If the fleet gets twice as fast, the "middle" gets faster, benchmark will double but the time will be half, and the number is the same. That calculation is then used to adjust the FLOPs calculation. Cobblestones don't change just because the median credit changes. The standard is very concrete. I've repeatedly said "a cobblestone is 1/100th of the daily output of a machine with these characteristics" -- the term "mean" or "median" does not appear in that sentence. I'm fine with your "HAL 9000" getting a billion credits per day. You should worry about it opening the pod bay doors. -- Ned |
zoom3+1=4 Send message Joined: 30 Nov 03 Posts: 66342 Credit: 55,293,173 RAC: 49 |
And while not wearing a spacesuit. ;) I'd have thought this less credit thing was dead, I guess I might need a space suit. Savoir-Faire is everywhere! The T1 Trust, T1 Class 4-4-4-4 #5550, America's First HST |
1mp0£173 Send message Joined: 3 Apr 99 Posts: 8423 Credit: 356,897 RAC: 0 |
Now I'm not saying CUDA is a bad idea. I actually think it is a good idea, but it has been let down by BOINC. The BOINC devs probably knew CUDA apps were on their way months before they appeared and yet over 6 months after the Seti CUDA app was released the BOINC client still has problems. As I understand it, Nvidia did just enough to port one of the two SETI science applications to CUDA, and then the developers at Nvidia were assigned to other projects. That may even mean that when Multibeam is updated (they've turned up the sensitivity more than once during the past decade) that the CUDA application will disappear. It's probably to early to call, but if the CUDA App. becomes abandonware, it's probably on Nvidia. We also kinda forget that BOINC is a development project too, and they have to answer to a lot of projects, not just SETI -- and one that has to cater to the projects as well as the users. Lots of useful work is being done successfully, so it's important to test thoroughly before releasing new versions, and testing takes time. |
Geek@Play Send message Joined: 31 Jul 01 Posts: 2467 Credit: 86,146,931 RAC: 0 |
I have come to believe that a person's RAC can go up and down naturally depending on the data being crunched and mainly on what the telescope was doing when the Seti data was recorded. Nothing we can do about it, it just happens. And those of us who crunch the same configuration for months and months at a time can see this. I have also observed that when everyone's RAC is going up, nobody complains or reports it. When everyone RAC starts to go down, due to the nature of the data being crunched, then more complaints show up here. That's just life with Boinc/Seti and distributed computing. Boinc....Boinc....Boinc....Boinc.... |
perryjay Send message Joined: 20 Aug 02 Posts: 3377 Credit: 20,676,751 RAC: 0 |
When my RAC goes up I figure I've done something right for a change. When it goes down I start looking for a problem. I usually stay out of these credit discussions since I'm not all that concerned about how much they give me, just so long as it's the same for everybody. PROUD MEMBER OF Team Starfire World BOINC |
Larry256 Send message Joined: 11 Nov 05 Posts: 25 Credit: 5,715,079 RAC: 8 |
So your your ready to make a stand against this proposal then.Message 701328 The issue that Henri started with on this thread: if credit scores are "normalized" so that the median host on SETI makes 100 credits/day, and all other projects are normalized so that the same median computer gets 100 credits/day, it does two things: I think your now against it because I'm fine with your "HAL 9000" getting a billion credits per day.,for the same reason I am. LOL |
Josef W. Segur Send message Joined: 30 Oct 99 Posts: 4504 Credit: 1,414,761 RAC: 0 |
That's the basic misunderstanding. If the benchmarks double, actual productivity might quadruple since the science apps tune themselves to processor capabilities. That's mainly why my 200 MHz. Pentium MMX and 1400 MHz. Pentium-M have benchmarks near the 1:7 clock rate ratio but the Pentium-M host is around 29 times more productive. Core i7 hosts running at clock rates around twice that of the P-M tend to benchmark 2.5 to 3 times higher, but seem to be about 5 or 6 times as productive. Architecture improvements have fairly small effects on the benchmarks but are very worthwhile for real computations. That calculation is then used to adjust the FLOPs calculation. The benchmarks are very limited, the Cobblestone is an elastic concept because benchmarks are only using the most basic computational capabilities possessed by all hosts. The original time * benchmarks credit method was a form of wages; each host took a little test and was 'paid' strictly on that basis. An 0.44x AR Enhanced WU takes about 388000 seconds on my Pentium MMX host and the credit claim would be about 95.1, the same AR on my Pentium-M host takes about 12602 seconds and the credit claim would be 27.4 or so. The older host would of course not be granted its higher claim, even the P-M would often be paired with faster hosts claiming less. The worst feature of the method was that it provided no motivation to improve science apps since they had no effect on how much 'pay' was given for a day's work. The fpops_cumulative method is a piecework approach, and definitely more equitable in my view though not perfect. The server-side adjustment is needed because nobody has yet come up with a better standard than the Cobblestone though the benchmarks are increasingly poor measures of compute capability. Joe |
1mp0£173 Send message Joined: 3 Apr 99 Posts: 8423 Credit: 356,897 RAC: 0 |
[edit/clarification]I'm starting with the statement that "If the definition of a cobblestone is..." and going from there. Changing the standard is a different (and probably worthwhile) discussion, but it's a different conversation.[/edit] I agree. My only caveat is that every benchmark is limited. The best story about this came early in my computing career, back when mainframes were the hot ticket (and smaller computationally than most PCs). There was a competition. The prospective buyer put out bids, and as I remember the competition was for a new mainframe, and they scored based on how well each system ran a benchmark. Each vendor had an early optimizing compiler. I don't remember the language but it was either Fortran or COBOL. ... and the benchmarks were compiled and run. One bidder reported the time: 0 seconds. The program had exactly two output statements, one that printed "start" and one that printed "done." That bidders optimizer traced back through the code and eliminated every statement that did not contribute to the output. Trouble is, not only is the Cobblestone defined in terms of benchmarks, but in terms of two specific benchmarks. If we're actually measuring credit in Cobblestones, then we have to remain faithful to the definition. |
1mp0£173 Send message Joined: 3 Apr 99 Posts: 8423 Credit: 356,897 RAC: 0 |
So your your ready to make a stand against this proposal then.Message 701328 I have because the post you referenced is factually incorrect. The post says the plan is to normalize credit so the median host gets 100 credits per day. What the script does (or at least tries) is normalize so that a moving average of 30 median hosts, selected from a daily sample over the past 30 days, would get the same credit using FLOPs as they would get using benchmark * time. Those are very, very different. |
Dirk Sadowski Send message Joined: 6 Apr 07 Posts: 7105 Credit: 147,663,825 RAC: 5 |
Thanks to all! Hmm.. finally.. someone [I mean someone, not all..! ;-)] should PM the Berkeley crew because of the 'credit adjustment script' which run periodically? Because to choose only CPU only PCs without CUDA GPUs for the 'average calculation'? |
Westsail and *Pyxey* Send message Joined: 26 Jul 99 Posts: 338 Credit: 20,544,999 RAC: 0 |
*thumbs up* That is the first time it has been explained so I understood. That is ideal and makes perfect sense. The voice I think many are raising, as well as my own previous concerns; were that credit would continually be "adjusted" so that my hot new machine today (sitting in 2012) would get the same rac my previous hot bang new machine had gotten when it what first brought online years prior. Where as it is actually doing say 4x the work the previous host did in the same time. Thanks! "The most exciting phrase to hear in science, the one that heralds new discoveries, is not Eureka! (I found it!) but rather, 'hmm... that's funny...'" -- Isaac Asimov |
-=SuperG=- Send message Joined: 3 Apr 99 Posts: 63 Credit: 89,161,651 RAC: 23 |
Is this why my RAC has dropped from 72,000 back in May to 61,000 today? Or is there some other sinister workings going on? Boinc Wiki "Great spirits have always encountered violent opposition from mediocre minds." -Albert Einstein |
Byron S Goodgame Send message Joined: 16 Jan 06 Posts: 1145 Credit: 3,936,993 RAC: 0 |
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zoom3+1=4 Send message Joined: 30 Nov 03 Posts: 66342 Credit: 55,293,173 RAC: 49 |
That appears to be what's going on, and from what I'm seeing of my pending credits, the trend seems to still be going down, so I'd expect it will drop further. Yeah It seems like the project is bound and determined to bring the rate down to zero. Savoir-Faire is everywhere! The T1 Trust, T1 Class 4-4-4-4 #5550, America's First HST |
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