3930K @ 4.2GHz, DDR3 1600, Linux, P95 v28.5.
[code]threads iteration time estimated completion time
1 121 ms 463 days
2 62 ms 237 days
3 42 ms 160 days
4 32 ms 122 days
5 26 ms 101 days
6 23 ms 89 days[/code]Not too bad for a late-2011 machine. I wonder what a 5820K, 5930k, or 5960x with good DDR4 would do (Haswell plus more memory bandwidth plus possibly higher clock speeds). It might still be more perf/$ to get two 4790K systems.

i7-4770K @ 3.5GHz, DDR3 1866MHz, Linux 3.13.0-37-generic, P95 v28.5.

[code]threads iteration time estimated completion time
1 98 ms 377 days
2 51 ms 197 days
3 37 ms 143 days
4 32 ms 123 days[/code]

The same above, but Turbo Boost ON (i.e. up to 3.9GHz) this time.

[code]threads iteration time estimated completion time
2 89 ms 342 days
2 47 ms 181 days
3 35 ms 134 days
4 31 ms 121 days[/code]

Hello Dana, I saw you have got this cpu overclocked at 4.3GHz and I'd like to overclock my 4700K too. Luckily or unluckily I'm from South Italy, so now max temps are 78°C under Noctua NH-L12 cooling (on summer 87°C). What's your heatsink? Temps?

for the sake of... competing :P

i7-2600k @3.8GHz, HT-on (remark the raising times at the logical cores)
100 iterations of 332220523

[CODE]
[Work thread Oct 27 22:08:11] Using AVX FFT length 19200K, Pass1=768, Pass2=25K
<... snip 100 lines ...>
[Work thread Oct 27 22:08:27] Iterations: 100. Total time: 13835.363 ms.
[Work thread Oct 27 22:08:27] Estimated time to complete this exponent: [COLOR=Red][B]531 days[/B],[/COLOR] 23 hours, 45 minutes.
[Work thread Oct 27 22:08:32] Using AVX FFT length 19200K, Pass1=768, Pass2=25K, 2 threads
<... snip...>
[Work thread Oct 27 22:08:49] Iterations: 100. Total time: 15520.924 ms.
[Work thread Oct 27 22:08:49] Estimated time to complete this exponent: [B][COLOR=Red]596 days,[/COLOR][/B] 19 hours, 14 minutes.
[Work thread Oct 27 22:08:54] Using AVX FFT length 19200K, Pass1=768, Pass2=25K, 3 threads
<... snip...>
[Work thread Oct 27 22:09:04] Iterations: 100. Total time: 7516.421 ms.
[Work thread Oct 27 22:09:04] Estimated time to complete this exponent:[COLOR=Red][B] 289 days[/B][/COLOR], 0 hours, 24 minutes.
[Work thread Oct 27 22:09:08] Using AVX FFT length 19200K, Pass1=768, Pass2=25K, 4 threads
<... snip...>
[Work thread Oct 27 22:09:18] Iterations: 100. Total time: 7895.573 ms.
[Work thread Oct 27 22:09:18] Estimated time to complete this exponent: [COLOR=Red][B]303 days[/B][/COLOR], 14 hours, 18 minutes.
[Work thread Oct 27 22:09:23] Using AVX FFT length 19200K, Pass1=768, Pass2=25K, 5 threads
<... snip...>
[Work thread Oct 27 22:09:30] Iterations: 100. Total time: 5347.423 ms.
[Work thread Oct 27 22:09:30] Estimated time to complete this exponent:[COLOR=Red][B] 205 days[/B][/COLOR], 14 hours, 47 minutes.
[Work thread Oct 27 22:09:35] Using AVX FFT length 19200K, Pass1=768, Pass2=25K, 6 threads
<... snip...>
[Work thread Oct 27 22:09:42] Iterations: 100. Total time: 5536.849 ms.
[Work thread Oct 27 22:09:42] Estimated time to complete this exponent:[COLOR=Red][B] 212 days[/B][/COLOR], 21 hours, 35 minutes.
[Work thread Oct 27 22:09:47] Using AVX FFT length 19200K, Pass1=768, Pass2=25K, 7 threads
<... snip...>
[Work thread Oct 27 22:09:54] Iterations: 100. Total time: 4698.894 ms.
[Work thread Oct 27 22:09:54] Estimated time to complete this exponent: [COLOR=Red][B]180 days[/B][/COLOR], 16 hours, 18 minutes.
[Work thread Oct 27 22:09:58] Using AVX FFT length 19200K, Pass1=768, Pass2=25K, 8 threads
<... snip...>
[Work thread Oct 27 22:10:05] Iterations: 100. Total time: 4960.807 ms.
[Work thread Oct 27 22:10:05] Estimated time to complete this exponent: [COLOR=Red][B]190 days[/B][/COLOR], 18 hours, 0 minutes.
[Work thread Oct 27 22:10:05] Worker stopped.
[/CODE]

For the sake of...... :razz:
[code]
[Oct 27 08:37] Worker starting
[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K
[Oct 27 08:37] p: 332220523. Time: 91.299 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.914 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 351 days, 10 hours, 27 minutes.

[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K, 2 threads
[Oct 27 08:37] p: 332220523. Time: 47.988 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.480 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 184 days, 13 hours, 37 minutes.

[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K, 3 threads
[Oct 27 08:37] p: 332220523. Time: 34.405 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.350 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 134 days, 14 hours, 7 minutes.

[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K, 4 threads
[Oct 27 08:37] p: 332220523. Time: 28.985 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.324 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 124 days, 15 hours, 23 minutes.
[Oct 27 08:37] Worker stopped.
[/code]

[QUOTE=kracker;386226]For the sake of...... :razz:
[code]
[Oct 27 08:37] Worker starting
[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K
[Oct 27 08:37] p: 332220523. Time: 91.299 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.914 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 351 days, 10 hours, 27 minutes.

[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K, 2 threads
[Oct 27 08:37] p: 332220523. Time: 47.988 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.480 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 184 days, 13 hours, 37 minutes.

[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K, 3 threads
[Oct 27 08:37] p: 332220523. Time: 34.405 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.350 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 134 days, 14 hours, 7 minutes.

[Oct 27 08:37] Using FMA3 FFT length 18M, Pass1=1536, Pass2=12K, 4 threads
[Oct 27 08:37] p: 332220523. Time: 28.985 ms.
[Oct 27 08:37] Iterations: 10. Total time: 0.324 sec.
[Oct 27 08:37] Estimated time to complete this exponent: 124 days, 15 hours, 23 minutes.
[Oct 27 08:37] Worker stopped.
[/code][/QUOTE]But what is the CPU/RAM combination there?

[QUOTE=retina;386229]But what is the CPU/RAM combination there?[/QUOTE]

Whoops. i5 4670K(stock) w/ Dual 2400MHz memory.

How come FMA3 is using 18M FFT while plain AVX is using 19200K? By what black magic is FMA improving calculation precision?!

[QUOTE=axn;386236]How come FMA3 is using 18M FFT while plain AVX is using 19200K? By what black magic is FMA improving calculation precision?![/QUOTE]

The extra heat from the speed of the FMA3 is so great that the CPU dare not give an accurate result even with an FFT length too small.

5820K @3.6, DDR4 @3000 (1500x2)

Not bad...