[QUOTE=VBCurtis;436427]..... remember that optimal sieving *barely* matters in overall project length; you could get away with 50% or 100% and it won't make very much difference.[/QUOTE]

If I may say: that logic is OK if you have many CPU cores. But if you have limited number of CPU cores , than every candidate removed by sieve is at least one hour less on fast AVX core

[QUOTE=pepi37;436432]If I may say: that logic is OK if you have many CPU cores. But if you have limited number of CPU cores , than every candidate removed by sieve is at least one hour less on fast AVX core[/QUOTE]

If you have fast and slow cores then yes you could change things around.

[QUOTE=pepi37;436432]If I may say: that logic is OK if you have many CPU cores. But if you have limited number of CPU cores , than every candidate removed by sieve is at least one hour less on fast AVX core[/QUOTE]

Huh? How does the number of cores have anything to do with the computation of optimal sieve depth? My advice is based on minimum project length- you can use just as many cores to sieve as you do to LLR, or you can use one core for the entire thing, or whatever you want; the project length is what we're trying to minimize, measured in computational effort rather than wall-clock time.

Are you saying a factored candidate will save more than one hour on your AVX core? Then you should sieve until it takes the sieve an hour or so to factor a candidate. I still don't get what you are trying to say.

As somebody stated before, optimum sieve depth is impossible to determine as we hope we don't need to test the whole candidate file. I've had files that I sieved from n=1M to n=2M only to find a prime at n=1.05M and all the sieving I did was basically wasted.

That's why I do some basic sieving, test a few candidates at different n-levels to get timing information and then switch from sieving to LLR and back and forth, depending on what is faster.

[QUOTE=VBCurtis;436455]....
Are you saying a factored candidate will save more than one hour on your AVX core? Then you should sieve until it takes the sieve an hour or so to factor a candidate. I still don't get what you are trying to say.[/QUOTE]


Yes, that is what I try to say. We all hope that prime will be at beginning of the file we process. But what if it on the end, or even there is no prime in our range. In that case, every candidate removed with sieve is less to process.

[QUOTE=rebirther;434996]Reserving S55 to n=500k (250-500k) for BOINC[/QUOTE]

Reserving to n=1M

S49
 

Thanks everyone for your advice on sieving depths.

R39 tested to n=100k (50-100k) (1.2-1.353M)

87 primes found, 232 remain in this range

Results emailed, Base released

[QUOTE=rebirther;437141]R39 tested to n=100k (50-100k) (1.2-1.353M)

87 primes found, 232 remain in this range

Results emailed, Base released[/QUOTE]

With this completion, CRUS has reached a big milestone. All bases <=50 except bases 3/7/15 have been completed to n=100K!

Nice work everyone! :smile:

R93
 

R93 tested 653K-700K - nothing found

Continuing to 1M

hi,
i do reserve R72 n=1000000 to 1500000