2002-10-20 22:12:53 +00:00
|
|
|
<title>Computation credit</title>
|
|
|
|
|
<body bgcolor=ffffff>
|
|
|
|
|
<h2>Computation credit</h2>
|
|
|
|
|
|
|
|
|
|
<p>
|
|
|
|
|
Each project gives you <b>credit</b> for the computations your
|
|
|
|
|
computers performs for the project.
|
|
|
|
|
These credits are used to generate web-site "leaderboards" showing
|
|
|
|
|
individuals, teams, and categories (countries, CPU types, etc.)
|
|
|
|
|
ranked by credit.
|
|
|
|
|
|
|
|
|
|
<p>
|
2002-10-22 01:26:21 +00:00
|
|
|
BOINC's credit system is based on a "reference computer" that does
|
2002-10-20 22:12:53 +00:00
|
|
|
<ul>
|
2003-01-02 23:12:05 +00:00
|
|
|
<li>1 billion floating-point multiplies per second
|
|
|
|
|
<li>1 billion integer multiplies per second
|
2002-10-22 01:26:21 +00:00
|
|
|
<li>4 billion bytes per second of traffic to and from main memory
|
2002-10-20 22:12:53 +00:00
|
|
|
(sequential, half reads and half writes)
|
|
|
|
|
</ul>
|
2002-10-22 01:26:21 +00:00
|
|
|
BOINC's unit of credit, the <b>Cobblestone</b>,
|
|
|
|
|
is one day of CPU time on the reference computer.
|
2002-10-20 22:12:53 +00:00
|
|
|
|
|
|
|
|
<p>
|
|
|
|
|
Each project maintains two types of credit:
|
|
|
|
|
<ul>
|
|
|
|
|
<li> <b>Total credit</b>:
|
|
|
|
|
The total number of Cobblestones performed.
|
|
|
|
|
<li> <b>Recent average credit</b>:
|
2002-10-22 01:26:21 +00:00
|
|
|
The average number of Cobblestones per day performed recently.
|
|
|
|
|
This average decreases by a factor of two every week.
|
2002-10-20 22:12:53 +00:00
|
|
|
</ul>
|
|
|
|
|
|
|
|
|
|
<p>
|
2002-10-22 01:26:21 +00:00
|
|
|
Both types of credit (total and recent average)
|
|
|
|
|
are maintained for each user and host.
|
2003-01-02 23:12:05 +00:00
|
|
|
|
|
|
|
|
<h3>Leader boards</h3>
|
|
|
|
|
The PHP pages supplied by BOINC include basic leaderboards:
|
|
|
|
|
top users and hosts, by total and average.
|
|
|
|
|
BOINC lets projects export the credit-related
|
|
|
|
|
parts of their database as XML files.
|
|
|
|
|
These XML files can be used to generate
|
|
|
|
|
other breakdowns of users, hosts and teams,
|
|
|
|
|
or to generate leaderboards based on the sum of
|
|
|
|
|
credit from different projects.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<h3>Possible future improvements</h3>
|
|
|
|
|
<ul>
|
|
|
|
|
<li>
|
|
|
|
|
Ideally, credit should reflect network transfer and disk storage as well
|
|
|
|
|
as computation.
|
|
|
|
|
But it's hard to verify these activities,
|
|
|
|
|
so for now they aren't included.
|
|
|
|
|
<li>
|
|
|
|
|
Eventually projects will develop applications that use
|
|
|
|
|
graphics coprocessors or other non-CPU hardware.
|
|
|
|
|
Credit should reflect the usage of such hardware.
|
|
|
|
|
To accomplish this, we will need to let
|
|
|
|
|
projects supply their own benchmarking functions.
|
|
|
|
|
This will also handle the situation where a project's
|
|
|
|
|
application does e.g. all integer arithmetic.
|
|
|
|
|
</ul>
|
