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The ZetaGrid FAQ
Please send comments and good questions for inclusion to the contact adresses on this website.
Further technical questions are discussed in the ZetaGrid Forum.

Content

  1. Introductory questions
    • Q1 How can I contribute ?
    • Q2 Why should I participate ?
    • Q3 I have a problem. Help!
  2. Installation & general technical questions
    • Q1 What is the difference between screensaver, service and commandline installations?
    • Q2 Is a constant Internet connection required to participate?
    • Q3 What if I am on vacation for 2 weeks and my computer is turned off? Is there a timeout for the work units?
    • Q4 What operating systems are supported and why?
    • Q5 What work unit size should I choose ?
    • Q6 Why is there a CPU intensity switch ?
    • Q7 How much RAM does the client take ?
    • Q8 How can I see the amount of work done? How can I check if I have delivered a work unit successfully ?
    • Q9 What are my odds to win a prize ?
    • Q10 How do I notice if I won a prize ?
    • Q11 Can we contribute as a group/team but still see our personalized results ?
    • Q12 Can I change my name, e-mail or team membership ?
    • Q13 How many data is transferred between the server and the client ?
    • Q14 I have a multiprocessor machine. Can ZetaGrid use multiple CPU's?
  3. Advanced technical questions
    • Q1 Are there differences in computing speed for the different versions and platforms?
    • Q2 What programming languages is ZetaGrid written in ?
    • Q3 How does the Zeta client and server communicate ?
    • How are the work units determined?

Introduction

Q1: How can I contribute ?
If you want to contribute to the calculation please go to the downloads page and install the respective client software. You have to supply your name and email address in order to be registered with the ZetaGrid server. If you want to stay anonymous you may choose so during installation, if not please be aware that your name will appear on the top producers list.
Apart from joining ZetaGrid by installing a client you may help by promoting the idea, and also by giving us useful tips on how to extend the software. As stated above, if you have tips for others on how to best use / configure / avoid pitfalls with ZetaGrid please send them to the ZetaGrid forum or to us, we'll put them into this FAQ.

Q2: Why should I participate ?
ZetaGrid is a private effort, and it is fully your decision to help Sebastian to keep and extend his record on calculating the zeroes. Of course, there is a little 'bribery' going on because of the prizes which you can win :-)
Also, your name will appear in our top producers list on the Internet. And if the proof succeeds then ZetaGrid will be very famous, and you have been part of it.

Q3: I have a problem. Help!
If you run into problems please first check the 'install_en.txt' or 'install_de.txt' hint files in the download section.
Secondly, you may want to consult this FAQ list or the ZetaGrid forum.
Thridly, please try again later, maybe after an extended coffee break or simply tomorrow :-)
If all that doesn't help please send an e-mail with a detailed description of what didn't work to the contact adresses. If an exception occurred please copy its text to the e-mail. If possible, please also include the '.cfg' Files from the 'c:\zeta' directory.


Installation & general technical questions

Q1 What is the difference between screensaver, service and command-line versions?
ZetaGrid starts a process to do the calculation on your computer. It can start this process in a number of different ways. The simplest way is that you issue a command, e.g. 'zeta.sh' under Linux or 'zeta.cmd' / 'zeta.bat' under Windows. Then the calculation begins.
For your convenience there exist two additional versions for use under Windows. The service is a daemon process which is automatically started whenever you start your Windows NT/2000/XP system. It always runs in the background, so you do not need to manually start the calculation. This is a low priority process (default).
The other version is the screensaver. There, Zeta calculation only takes place when the screensaver is active. It is suspended as long as you use the computer. Thus, you do not have any performance effects during your normal work with the computer, but of course the overall calculation speed is slower.

Q2 Is a constant Internet connection required to participate?
No, ZetaGrid only needs a connection to download the work units and return the results. During the calculation you may be offline. If you stay offline for a longer time period you may want to reserve multiple work units, so you do not run out of work. This can be configured in the 'zeta.cfg' or via the screensaver dialog.

Q3 What if I am on vacation for 2 weeks and my computer is turned off? Is there a timeout for the work units?
As ZetaGrid is a dynamic system of course we have to take care of work units which are reserved too long. The current timeout value is seven days, and after that time the work unit may be resend to another client.
You should make sure that you have returned your results within this timeframe, otherwise they are - we hate to admit it - ignored.

Q4 What operating systems are supported and why?
We support the operating systems we have access to and, of course, which are most widely used in the community. To us they are Windows, Linux, AIX, Mac, and SunOS.
For OS/2 we currently do not have the time to generate a specialized version. Feel free to download the source code and try your luck with the 'how-to-build' instructions. If you succeed please send us an email, so we can look at it and possibly include into our list.

Q5 What work unit size should I choose ?
Work unit size determines how long your computer works on one unit. After about 1 week there is a timeout which invalidates a work unit. So if you choose a large work unit size and do not finish its calculation in a couple of days you run the risk that your work is redistributed, and your result wasted. Also, the amount of data transferred is larger, so you need to wait longer for transfer over the Internet.
Work unit size (and number of work units) are only really relevant if you are offline. You have to judge how much you calculate between different online sessions and then decide which parameters fit you best.

Q6 Why is there a CPU intensity switch ?
Some computers really have some problems with running full speed all the time. This can happen both for laptops as well as desktop machines. For these machines, you should set the intensity switch to medium or low, so that the CPU's do not overheat.
Basically, what ZetaGrid does is taking some idle cycles every now and then.

Q7 How much RAM does the client take ?
There is a parameter in the 'zeta.cfg' file (resources=x) to define how much RAM should the client take. The default takes about 37MB main memory in Windows. It is possible to use up to 51MB main memory to speedup the computation.

Q8 How can I see the amount of work done? How can I check if I have delivered a work unit successfully ?
In Windows you have the ZetaGrid control center which shows your work, for the other OS there is the 'zeta_progress.sh' command or other useful supplementaries on the download page.
The delivery of the work unit can be seen in the relevant statistics page on the ZetaGrid server under your name. It is updated roughly every 10 minutes.

Q9 What are my odds to win a prize ?
Well, all the rewarded situations have not been found yet, so there are none within the first 100+ billion zeros. We do not have any estimation about the probabilities, but it might just be that these situations will occur...

Q10 How do I notice if I won a prize ?
There is an automated detection mechanism which runs for every completed work unit. If a match occurs the administrator will be notified, who in turn will send you an e-mail.

Q11 Can we contribute as a group/team but still see our personalized results ?
Yes, you can optionally define a team name and still see our personalized results. But it is recommended for everybody to define a valid e-mail address who want to contribute as a team because you will get an e-mail with a unique link to approve your change if you want to change your team membership.

Q12 Can I change my name, e-mail or team membership ?
The pair (name, e-mail) is the unique identifier for ZetaGrid. In every statistic the e-mail address is not viewed and the results are summarized for every name (not case sensitive). Therefore, you will have a new identifier if you change your e-mail but you contribute for the same name in the statistics.
You will get an e-mail with a unique link to approve your change if you want to change your team membership. This e-mail will be generated from the server if the client requests new work units. In some situations you will never receive an e-mail if your address is not valid or your mail server rejected e-mail SPAM addresses. But you approve only your unique identifier (name, e-mail) and not every user with the same name. You have to change your team membership in the configuration of all computer. Otherwise the ZetaGrid server will send you different approvals (to change back to your previous team) after every request for new work units. All statistics will be changed with your new team membership in about 2 hours if you approve your change at the server. A team can only exist with at least one member.

Q13 How many data is transferred between the server and the client ?
For the normal-size work unit (default) about 450kB of result data has to be transferred.

Q14 I have a multiprocessor machine. Can ZetaGrid use multiple CPU's?
Yes, there is a switch in the 'zeta.cfg' file (processors=x) to enable multiple threads which can each run on a different CPU in your computer. Work units cannot be shared among different CPU's, so you have to have one work unit for each thread.
If you have more than 5 processors please contact us, because the standard client has a limit of 5.


Advanced Technical Questions

Q1: Are there differences in computing speed for the different versions and platforms?
Yes, there are. Apart from the CPU speed which obviously determines the calculation speed also the compilers behave differently. For Windows we have these performance figures for different CPU's (Thanks to Walter Selg for these figures):
Pentium III 800 MHz / PC133 SDRAM --- Processing time for 1 work unit: ~ 4:00 h
Athlon 700 MHz / PC133 SDRAM --- Processing time for 1 work unit: ~ 6:30 h
The interesting part here is that ZetaGrid is slower on an AMD Athlon than on Intel Pentiums. Our guess for a reason is the optimizing Intel compiler which was used to compile the calculation code for the Windows platform.

Q2: What programming languages is ZetaGrid written in ?
The ZetaGrid client which does the administration and security is completely written in Java. It gets work units, updates and transfers the results. The calculation itself is done using a DLL (or library in Linux, AIX etc) which are implemented in C++ and Assembler.

Q3: How does the Zeta client and server communicate?
Client-Server communication in ZetaGrid is quite straightforward. The client connects via HTTP (also a proxy can be configured) to one of several servlets on the server, depending which function it wants to use. There is a servlet for initialization which delivers an updated client and checks status, a servlet to get a work unit, one to return a work unit and one to transfer certain statistics about the client.
The large result transfers are optimized and compressed before the transfer, effectively reducing the bandwidth needed.


Version history
  1. Oct 1, 2002: first version created by Ralf Grohmann
  2. Dec 28, 2002: FAQ about the new team functionality added by Sebastian Wedeniwski
  3. Oct 19, 2003: completely revised by Sebastian Wedeniwski