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-   -   How long should a sieve reservation be? (https://www.mersenneforum.org/showthread.php?t=6790)

BlisteringSheep 2006-12-15 00:42

reservation sizing assistance
 
[quote=BlisteringSheep;94085][COLOR=blue]411000-413000 reserved by BlisteringSheep[/COLOR](comb)[/quote]

I apologize for all of the small reservations lately. I'm trying to keep everyone loaded without being too greedy. I have also been adding machines (another 10 CPUs today, for a current total of 114). If anyone has some advice on good sized ranges I should be taking to minimize the overhead that I put everyone through here are my specs:[LIST][*]86 of them process at about 332000 p/sec[*]28 of them process at about 285000 p/sec[/LIST]I'm using the SoB.dat from the sievecomb.zip link at the top of this page. As always, thanks for being patient with me.:blush:
:alex:

VJS 2006-12-15 15:16

Sheep I don't think anyone ever has to apologize for reserving too much! Also the amount of work for scoring and managing the factors is not all that great. Takes quite a few minutes certainly but I'm sure your CPU time donation is well worth the personal time offset.

If you want my advice on range sizes...

Sieve a range is not something that needs to be done quickly after a reservation is made. In addition if one reserves a large chunk and sits on it for a month or two it doesn't really hurt the project either, especially if it's inadvance of the current reservations and you actually do complete the range.

So my advice would be, reserve about a months worth per CPU as one range, IMHO one month is actually a midsize reservation time wise.

That would be about 1000G for either processor... speeds are not all that different probably take between 4-6 weeks. I don't think anyone would complain if you reserved something like...

530000-577000
579000-646000

That would give you 1000G per processor.

Any other suggestions or comments from others???

Xentar 2006-12-15 16:01

no suggestion, just a little hint:
in the SoB forum,
[url]http://www.free-dc.org/forum/showthread.php?t=3501[/url]

there is a little MS Excel file, called "Sievecalc". This file helps you calculate your ranges: you just write your sieve speed, and it calculates, how much G you can do in one day, week and month. It also calculates, how long you will need for a specific range, so you dont have to do it on your own.

BlisteringSheep 2006-12-15 16:24

VJS & Xentar,
Thanks! That is exactly the sort of guidance I was looking for. One last question/example:
Say I know that on one set of boxes I want to sieve range A-B and on the other I want to sieve range B-C (such that A-C is a contiguous range). These two ranges will not be completed at the same time, and are being done in different physical locations, and the results will be reported separately (ie. as factorsA-B and factorsB-C). What is the preferred way to do the reservations: as two reservations or as one lump A-C reservation?

Again, thanks in advance for your patience.
:alex:

P.S. Of course, one option is for you to say "Shut up with your stupid questions and go away, you're too much trouble." :sad:

Joe O 2006-12-15 16:33

[QUOTE]Any other suggestions or comments from others???[/QUOTE]
A month is at the edge of what I would recommend. Two weeks would be better from my point of view, three would even work. The problem with large chunks in advance of current reservations, is that they tend to be forgotten.
I'm sure that 200000-204000 was reserved way in advance of the then current reservations. Now it is far in the rear of completed ranges. This tends to cause problems for the project administration.

Joe O 2006-12-15 16:55

[QUOTE]What is the preferred way to do the reservations: as two reservations or as one lump A-C reservation?
[/QUOTE]
Depends on how far apart they will finish. If within a week then I would recommend reserve A-C and report it as one range. If longer, then two ranges so that the benefits of the A-B range can be felt ASAP. Remember, the found factors can prevent LLR tests.

ltd 2006-12-15 17:06

I agree with Joe's suggestions about reservations for BlisteringSheep.
But from my feeling 3-4 weeks would still work. I reserve normally for 4 weeks.


Lars

odessit 2006-12-16 14:20

Just to make sure I follow everyone - the Sieve test should not run more than 1 month or else it causes problems (unnecessary work)?

hhh 2006-12-16 16:22

...or else it is succeptible to cause unneccessary work. The thing is that it should be finished before it arrives at the bottom of the reservation list and gets stuck there all alone for a long time. If everybody takes the reservations below some reasonable limit(one month), this will not happen. H.


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