24 Feb 2005 5:44:56 UTC

Topic 187929

(moderation:

I've tried the documentation and the FAQ, and can find no explanation of how claimed credit is calculated. It does not seem to be determined by time alone.

I ask because most of my returned WU's claim 50 points, while many others claim about 100. In the end I get the 100 or so points because the validator uses the middle value of the many validated, but I'd rather not be the one that pulls someone's high credit WU down in points.

Bruce Wilson

http://wilson.dynu.net

Language

Copyright © 2021 Einstein@Home. All rights reserved.

## How is claimed credit determined?

)

Bruce

The easy formula to use is this

claimed credit = ([whetstone]+[dhrystone]) * wu_cpu_time_in_sec / 1728000

Since two of your computers are using HT your benchmarks will be lower than if you had just one cpu. If you check the other results that claimed 100 you will probably see that they have only 1 cpu. The good thing about it is you get more credit and can run two WU's at the same time.

BTW nice photos. For img_4141, it is sad that others felt the need to write on and around it.

## Credit is granted in

)

Credit is granted in "cobblestones" and a cobblestone is 1/100 day of CPU time on a reference machine that does 1000 whetstones and 1000 Dhrystones for the benchmarks. So that's how the benchmark influences credit claimed and credit granted.

Thats the best I can come up with ;-/

Maybe someone else can do better...

Ooops I see someone did, Excellent! :-)

Great photos Bruce!

## > I've tried the

)

> I've tried the documentation and the FAQ, and can find no explanation of how

> claimed credit is calculated. It does not seem to be determined by time

> alone.

>

> I ask because most of my returned WU's claim 50 points, while many others

> claim about 100. In the end I get the 100 or so points because the validator

> uses the middle value of the many validated, but I'd rather not be the one

> that pulls someone's high credit WU down in points.

I see what is missing. You wanted the FORMULA ...

why didn't you complain to the management? :)

I will add the formula to the Glossary entry for Claimed Credit ...

Also note that there are still discrepancies between the claims made by different platforms, the benchmark scores of your computers will vary quite a bit, and so, the claim per WU will vary over time ...

## Steve, > The easy formula

)

Steve,

> The easy formula to use is this

> claimed credit = ([whetstone]+[dhrystone]) * wu_cpu_time_in_sec / 1728000

Where did you find this?

I mean it seems to be accurate, I was just wondering ...

## > I've tried the

)

> I've tried the documentation and the FAQ, and can find no explanation of how

> claimed credit is calculated. It does not seem to be determined by time

> alone.

Now I have examples for how this calculation plays out ...

Enjoy!

## Thanks, guys. I've been

)

Thanks, guys.

I've been on a lot of boards (ham radio, photography, web coding, etc) and this is by far the most responsive and helpful of them all!

Bruce Wilson

http://wilson.dynu.net

## > Thanks, guys. You are

)

> Thanks, guys.

You are welcome! :)

I am always trying (I know, very trying), along with others to make it easiser and better for all participants.

Did the examples I drew up help?

> I've been on a lot of boards (ham radio, photography, web coding, etc) and

> this is by far the most responsive and helpful of them all!

Yes, well, we also have our few that sometimes seem more interested in strife than anything else. So, we are not perfect either ...

And I have been known to get "cross" a time or two ...

## > Steve, > > > The easy

)

> Steve,

>

> > The easy formula to use is this

> > claimed credit = ([whetstone]+[dhrystone]) * wu_cpu_time_in_sec /

> 1728000

>

> Where did you find this?

>

> I mean it seems to be accurate, I was just wondering ...

>

Paul

I got the formula from a thread on seti that I think Benher had posted. He had the long and simplified version of the formula. If you want to know the longer version here is what I copied from that thread.

Credit is claimed according to the following formula:

claimed credit = ([whetstone]+[dhrystone])/1000 * 100 / (2 * secs_per_day) * wu_cpu_time

or to simplify the equation, claimed credit = ([whetstone]+[dhrystone]) * wu_cpu_time / 1728000

Note: wu_cpu_time is the time taken to process the unit in seconds.

I guess I should have mentioned and you may want to put it in your documentation that the formula will not work for CPDN since they have a set amount of credit.

## > > Did the examples I drew

)

>

> Did the examples I drew up help?

>

Yes they did, Paul, but you refer to an image in your explanation that I didn't see.

Bruce Wilson

http://wilson.dynu.net

## > Bruce > The easy formula to

)

> Bruce

> The easy formula to use is this

> claimed credit = ([whetstone]+[dhrystone]) * wu_cpu_time_in_sec / 1728000

> Since two of your computers are using HT your benchmarks will be lower than if

> you had just one cpu. If you check the other results that claimed 100 you will

> probably see that they have only 1 cpu. The good thing about it is you get

> more credit and can run two WU's at the same time.

>

> BTW nice photos. For img_4141, it is sad that others felt the need to write on

> and around it.

>

There is a project specific constant that is be applied to the formula to reflect how much of the work is Floating Point and how much is Integer.

claimed credit - ( a * whetstone + (1 - a) * dhrystone) * wu_cpu_time_in_sec / 1728000.

where a is the fraction that should be attributed to the whetstone portion of the computation. I can never remember which is which.

BOINC WIKI