should have the 400 million test done in 12-13 minutes if it worked linearly

[QUOTE=science_man_88;222419]should have the 400 million test done in 12-13 minutes if it worked linearly[/QUOTE]

It will take slightly longer than linear. The expected number of tests rises slowly, and the cost of each test is higher as the numbers get bigger.

[QUOTE=CRGreathouse;222421]It will take slightly longer than linear. The expected number of tests rises slowly, and the cost of each test is higher as the numbers get bigger.[/QUOTE]
means the next test may have to be done on a faster computer as linearly it should be over 10 hours on my machine(I only have 11 until i usually try to go to bed). oh and then the next test should take over 100 hours or over 4 days.

*** last result computed in 1h, 2mn, 56,844 ms.

does your code break if it finds one before running out ? if not wouldn't that likely speed it up ? it only needs to find one not all of them.

[QUOTE]does your code break if it finds one before running out ? if not wouldn't that likely speed it up ? it only needs to find one not all of them.[/QUOTE]

If it happens to find one, just press Ctrl + C after it is found.

[QUOTE=3.14159;222437]If it happens to find one, just press Ctrl + C after it is found.[/QUOTE]

so i need it showing again ? I changed it to not showing also I think it only prints once it's done the gone through the loop.

[QUOTE=science_man_88;222434]does your code break if it finds one before running out ?[/QUOTE]

If it finds one what, a Goldbach counterexample? No, the code doesn't break -- although you won't find one, all small numbers have already been tested.

[QUOTE=CRGreathouse;222440]If it finds one what, a Goldbach counterexample? No, the code doesn't break -- although you won't find one, all small numbers have already been tested.[/QUOTE]

no if it finds a prime pair so it only has to find one not 1000 lol

[QUOTE=science_man_88;222441]no if it finds a prime pair so it only has to find one not 1000 lol[/QUOTE]

Oh, certainly. The code would take vastly longer otherwise, and it would need a large primelimit.

is there a way we could speed it up as data is rarely random according to a ASM book I read into lol.

[QUOTE=science_man_88;222443]is there a way we could speed it up as data is rarely random according to a ASM book I read into lol.[/QUOTE]

Did you have something particular in mind?

You could get a small speedup by installing (possibly as a second OS rather than replacing your primary) some form of Linux, installing gp2c, running the script through gp2c, and hand-editing the C code to type-specialize, as well as to replace general functions with custom specific functions. But for this problem, most of the time is just spent proving primality, so there's no a whole lot to be done.