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Message boards : NFS Discussion : Welcome from a new adminish person

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Thomas Womack
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Message 1469 - Posted: 25 Jan 2015, 11:51:05 UTC

Good morning, and happy 2015 to all.

Though I have spent thousands of core-hours on this project, I've not personally run a single unit of NFS@home; what I do is the setup process (finding polynomials for GNFS) and the completion (running the linear algebra and actually finding the factors).

The last month I've been trying to work out good parameters for doing larger GNFS jobs on the 14e and 15e queues; I believe it will be possible to run 190-digit GNFS at 15e and 175-digit GNFS at 14e without too much trouble. These will use 32-bit large primes, which makes the linear algebra take a bit longer, but I have fourteen modern cores available for linear algebra (and will likely have more by the end of the year, depending on what the i7-57xx series of processors look like).

The big question is how many relations are needed for 32-bit jobs at this size; I think that can only be determined by experiment, so I'm doing the experiments.
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Profile Carlos Pinho [TSBTs Pirate]
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Message 1470 - Posted: 25 Jan 2015, 12:22:29 UTC
Last modified: 25 Jan 2015, 12:49:41 UTC

Thank you for joining us on the forum. Your expertize will help us all to understand what is happening in the backstage of NFS@Home.

So can you tell the members with no possibility to run 16e wu's (memory issues) what application they should concentrate on? lasieved (14e) or lasievee (15e)?

Thomas Womack
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Message 1473 - Posted: 25 Jan 2015, 19:41:50 UTC - in response to Message 1470.

Personally I would prefer people to concentrate on 15e: the jobs that 14e is doing could just about feasibly be run by individuals (I have personally run a few 250-digit SNFS and 170-digit GNFS jobs, they take 20,000 thread-hours which comes to two months on two current quad-core PCs with hyper-threading) whilst the 15e jobs are getting nearer the 100,000 total-CPU-hour mark and you're really doing something that an individual would have some difficulty with.

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