Bill, I've added your FAQ to the Boinc Wiki.

---

BOINC miniFAQ
Team ACC Forum
JOIN Team ACC

Bill, I've added your FAQ to the Boinc Wiki.

Um... hope you got the fact that it's not _MY_ FAQ. I just reposted it and made it sticky because the original thread was getting long and confusing. Credit goes to hugothehermit - I didn't write any of it...

---

Credit goes to hugothehermit

agreed

---

I've added a credit, linking back to this page :)

---

BOINC miniFAQ
Team ACC Forum
JOIN Team ACC

I fiddled with it some. So, best check my work ...

Adding the category allows us to "group" the FAQs ... now, if someone wants to try to do the science one ....

---

Clean nice :-)

But Bill/Mod whould you like ideas posted to this thread and then Mod periodically updates FAQ, moves out post ?

OR a thread where idea can be added (although this would get lost ofter a few days of no posts to it ?

Hopefully get some more time to think of more FAQ (or notice what is often talked about in the forums)

---

Team mauisun.org

Just a radical thought, but you could also point them to the version in the Wiki where we also add other links ... I don't mind either way ...

The WIki copy of the FAQ is: Rosetta@Home FAQ ...

And, of course the base reference which has other interesting links: Rosetta@Home Project

---

G'day all,

I have to say to mod9 that you are doing a terrific job, I never thought of linking to the messages.

I realise that a mod will move this post to "Posts moved from the FAQ thread (house cleaning)" but I thought I should show my head here again and tell everybody (that bothers to read the FAQ :) ) what happened, as I sort of left in a hurry.

I was attempting to create the FAQ's, with the help of a few good souls (who certainly know who they are), and found out my fathers cancer treatment was no longer working. I, as you would understand, spent all my available time with both my father and my family.

My father died about a month ago now, and I really haven't been up to any sort of communication, yet alone with help for those having problems. I don't think that I will be able to properly focus on the FAQ or even the other issues that R@H has for a while yet, but I felt I owed everybody an explanation.

BTW I think Bill Michael is just about ready to scream, he did contribute to a question on the memory swapping change version question (if it's still in the FAQ's ) and some format suggestions that I didn't have time to implement, and some OS installation stuff that got cut as the FAQ was getting too big, other than that, he as a mod with the name Bill Michael made the "FAQ work in progress" sticky.

Stop blaming him, especially for the how to swap work on computers question / answer. That is my fault for keeping that in the FAQ and no one else.

All the contributers to the FAQ's are not linked with Rosetta@Home and are volunteers just like you.

PS to all mods: can you leave this for about 48hours before you move it please, so that all concerned can read it.


PPS It would be nice to have a "back to the top" on all of the answers, I know that is a power of trouble but it would still be nice.

---

Why should I set BOINC to keep application in Memory?

If the application is removed from memory during an application swap, it will loose the work performed since the last checkpoint. In the case of Rosetta the checkpoints occur each time the percentage advances. Since is takes nominally 90-120 min between 10% checkpoints, if you do not keep the application in memory, and you set the swap interval to less than the time it takes your machine to reach a 10% mark, the work units can appear to be 'hung". This is why the recommended configuration is to set "Keep applications in memory" to "YES". As an added protection, it is also recommended to set a value of nominally 120 min between application swaps. Either of these settings alone has been shown to reduce the problem, but they can be used togeather for better results

It should be noted that ALL BOINC projects suffer from loss of CPU cycles if the applications are not kept in memory. Any work that is not save at a checkpoint before a swap, is lost when a swap occurs. On applications like Rosetta and Climate prediction this loss is significant (15 min to over an hour). On projects like Predictor, SETI and Einstein, the loss is less but it is still there (usually 60 seconds using the default setting for writing to disk). People who wish to squeeze every cycle out of their machine, usually keep applications in memory for this reason.

It is important to note that the memory we are talking about is not actual RAM but in fact is virtual memory (on disk), so the actual impact of this is not that significant. In addition you can adjust how much memory is used by the application in this regard.


Question submitted by:
Dimitris Hatzopoulos
Team:
Greece United

Dimitris,

My compliments on two pieces you've written in this FAQ, the one above and "What is project 'Swapping' and how should I have it set?". I'm learning from them. I value that. Additionally, I'm about to change settings on my BOINC, to include adding Rosetta back into the mix on my machine. (Don't get real excited about that. In today's world, this is a bit of a slow machine.)

As a means of suggesting additional material to cover, possibly adding still more strength to your writeups, I'll offer these questions:
- When BOINC decides on an application swap, putting Rosetta data on disk in virtual memory and the machine reboots before Rosetta gets the processor again, what happens to the data in virtual memory? Lost? Checkpoint just before BOINC closes out?
- Is there some reason the Rosetta application doesn't do a checkpoint immediatly before an application swap? Is BOINC designed to order the application to do a checkpoint and delay the swap until the checkpoint is complete?
- How many checkpoints does Rosetta take each work unit? Your writeup says, "In the case of Rosetta the checkpoints occur each time the percentage advances. Since is takes nominally 90-120 min between 10% checkpoints". As I read the first part of that, it sounds like Rosetta does roughly 100 checkpoints. The second part sounds like Rosetta does roughly 10 checkpoints.
- In the article, "What is project 'Swapping' and how should I have it set?", you include, "Once set, this preference will apply to all active projects on your machine. For this reason you may see some performance issues on your system." What performance issues? What range of performance change should I expect? What characteristics of my machine determine the particular performance change?

So often, if one person has these questions, many more will benefit from seeing the same answer. I have them; I offer them to you hoping I'm helping. Thanks in advance for any answers you decide to include.

Regards,

. . . Garry

---