I looked through the BOINC FAQ service http://boincfaq.mundayweb.com/ and the online client help https://boinc.berkeley.edu/wiki/Advanced_view don't mention the "Show host average"/"Show user average" are actually RAC.

Are the host/user average numbers shown on the graphs identical to RAC?
(It would be nice if the online manual about the statistics tab mentioned RAC directly.)


The variable labeled 'RAC' doesn't agree across three stat sites and I'm assuming much of that is because the Asteroid's project is down till January and 3rd party sites are unable to poll that server for credit results.
Free DC has a number very close to what "Show user average" reports but BOINC Synergy and BOINCStats are in agreement and less than half the value.

FDC and BOINCStats have their own RAC calculations. FDC has their 28 day average FDC RAC http://www.setiusa.us/showthread.php?644-BOINC-Stats-and-Calculations and
BOINC Stats has BS-RAC calculated on up to the last 60 days (less if new client) http://boincstats.com/en/page/faq#61.
Those two RAC's shouldn't be effected if access to a server isn't available as they are running averages stored at the 3rd party site.

The client "Show user average" page has an upward trending graph since December 15th (showing above 28,300 today) which is quite different from the following chart and I'm curious what happens to the blue line the day the Asteroids server is back online:

The expansion of the acronym RAC is Recent Average Credit. So 'averages' in BOINC-speak are the same as RAC, but possibly reported (and recorded) at different times by the various aggregation sites.

Boinc Stats-RAC is also an average, but with a different decay function. The standard BOINC RAC decays with a half-life of 7 days.

The expansion of the acronym RAC is Recent Average Credit. So 'averages' in BOINC-speak are the same as RAC, but possibly reported (and recorded) at different times by the various aggregation sites.

Boinc Stats-RAC is also an average, but with a different decay function. The standard BOINC RAC decays with a half-life of 7 days.

So then without any doubt, and with absolute certainty, (since it doesn't state this in any documentation) the "Show host averages" is exactly the same as RAC for that host?
I'll say the answer is NO because of a bug in the client.

If the half life decay is 7 days then why did the local client graphs take 12 days from when Asteroids@Home server going down to finally showing the loss of incoming WU's?
My assumption would be the client doesn't properly calculate decay when servers are unresponsive and I would like to see the algorithm/formula of the RAC calculations.

Just to be clear, this was irritating and confusing, because the client showed a rising trend for my account since December 15th while the three aggregate sites showed downward trends.
I consider this a bug in the client software.
It's not properly reporting RAC and the graph shown is indeed NOT the RAC when a server is unresponsive for several days (assuming the RAC is a typical decaying average computation).

Yes, I knew what the RAC acronym meant...

OK, here you go.

http://boinc.berkeley.edu/gitweb/?p=boinc-v2.git;a=blob;f=lib/util.cpp;h=6ee94fb745b866bf4821c3a62fe52a583e404f01;hb=HEAD#l229

That's the current code - function update_average() returns an intermediate value called 'weight' - that's your RAC.

Note that this code is executed entirely on the server: most commonly when a task is returned and validated. If no tasks are being validated, then - to a first approximation - credit and RAC are not updated.

Note also that validation is carried out asynchronously:

* You report a completed task and drop the connection
* The server validates the task (if possible - requires a running server and a wingmate)
* The server calculates the new values for credit and RAC
* You contact the server again, to request or report work.
* the server reply contains the updated values calculated while you were disconnected
* Your client retrieves these updated values from the reply, and updates the statistics graphs.

The transfer of credit and RAC values to external stats sites is also asynchronous. The server (assuming it's running properly) periodically generates a complete database dump of all (host, user, team) credits: usually once every day, although projects can set their own interval. You can check the current state of the Asteroids stats export at http://asteroidsathome.net/boinc/stats/ - it should match what your account pages showed for your credit and RAC at or about 29-Dec-2014 14:50 (or up to 24 hours before you read this message). There are the files which are used to generate the tables and graphs used by every external stats site - but since it takes a finite amount of time to notice the availability of a new set of files, download them, decompress them, and process them into their own statistics database. During this process, a slow site may still show yesterday's values, while a fast one shows today's - but that should be the only difference (E & OE).

the client doesn't properly calculate decay

That's where the confusion has arisen. The client doesn't ever calculate credit, RAC, or decay - that's only done on the server. The client only calculates REC, as we've discussed in another place.