I am very disappointed by the Intel® Xeon® Processor E5-2630 v2 performance for k=5 at n=3880k range. It is almost 800 seconds slower than my laptop (Toshiba Satellite L850-1HZ with Intel® Core™ i7-3630QM Quad Core (Ivy Bridge) ).

If you are using all 6 cores than you are almost certainly saturating the memory bus. I did some testing with an E5-2680 which has similar memory bandwidth. With up to 4 cores there was no slowdown. With 6 cores the slowdown was so much that the overall throughput was less than with only 4 cores. It was only with 8 cores that the extra cores made up for the bandwidth constraints and the total throughput was greater than with 4 cores, ie. the slowdown is not linear once you exceed 4 cores.

Note that my testing was with 80K FFTs. I don't whether the larger FFT size you will be using is likely to also exceed the 2.5 MB L2 cache per core.

3726-3746 complete, no primes.

[QUOTE=amphoria;360638]If you are using all 6 cores than you are almost certainly saturating the memory bus. I did some testing with an E5-2680 which has similar memory bandwidth. With up to 4 cores there was no slowdown. With 6 cores the slowdown was so much that the overall throughput was less than with only 4 cores. It was only with 8 cores that the extra cores made up for the bandwidth constraints and the total throughput was greater than with 4 cores, ie. the slowdown is not linear once you exceed 4 cores.

Note that my testing was with 80K FFTs. I don't whether the larger FFT size you will be using is likely to also exceed the 2.5 MB L2 cache per core.[/QUOTE]

One core is used while the others are doing some DNS simulations (CFD simulations).

3930-3940 complete, no primes.

Let's update first post with:

[B]The latest test file[/B]
The file contains all candidates in the 4-5M range.
Please help yourself by extracting the range you want to test.
Extensively sieved by Psieve (latest update of November 30, 2013 ~337P)
[B]Link to file here[/B] (35016 candidates)

From my side I have now 8 cores on my current k=5 ranges and then I will add more 4 as my 1st and 2nd megabit drive ranges finishes so I can dedicate all cores to k=5 for next year.

Carlos

The first post is updated!

And I'm taking 4000-4010.

[QUOTE=Kosmaj;361086]
And I'm taking 4000-4010.[/QUOTE]

Damm you...lol Good luck.

[B]The latest test file[/B]
The file contains all candidates in the 3-4M range, including already tested ones.
Please help yourself by extracting the range you want to test.

should be

[B]The latest test file[/B]
The file contains all candidates in the 4-5M range, including already tested ones.
Please help yourself by extracting the range you want to test.

Taking 4010-4090.
(Just queuing up more work due to the fact that I will be away from the computers)

3756-3766 complete, no primes.