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Search: Posts Made By: paulunderwood
Forum: Information & Answers 2021-06-24, 13:56
Replies: 19
Views: 369
Posted By paulunderwood
It would seem to me you have a duff CPU or maybe...

It would seem to me you have a duff CPU or maybe a duff motherboard.
Forum: Hardware 2021-06-24, 13:49
Replies: 8
Views: 94
Posted By paulunderwood
I am testing on a similar Odroid a73 chip. It...

I am testing on a similar Odroid a73 chip. It takes over six months per test with mlucas -- no certifications yet.

I doubt you'll see enough UK sunlight to power it flat out all year round.
Forum: Information & Answers 2021-06-24, 10:45
Replies: 19
Views: 369
Posted By paulunderwood
To reiterate, to solve your particular hardware...

To reiterate, to solve your particular hardware error problem, try underclocking the RAM :smile:
Forum: Miscellaneous Math 2021-06-23, 18:29
Replies: 17
Views: 1,378
Posted By paulunderwood
GMP is an order quicker than Pari/GP for this...

GMP is an order quicker than Pari/GP for this task. I have attached my GMP code. Note that it misses out x^2-x-4, but it would take a minute to test this special case with Pari/GP.

I fixed that...
Forum: Information & Answers 2021-06-22, 20:27
Replies: 19
Views: 369
Posted By paulunderwood
You are running at stock on good hardware. ...

You are running at stock on good hardware.

My Intel Haswell will not run a Linux kernel unless the CPU is slightly overvolted. Maybe upping the CPU voltage a tad -- say 0.05v -- on your system...
Forum: Hardware 2021-06-22, 05:12
Replies: 197
Views: 26,928
Posted By paulunderwood
I can only think you program this as: ...

I can only think you program this as:

numactl -m 1 stage1; numactl -m 0 stage2
Forum: Miscellaneous Math 2021-06-21, 23:34
Replies: 17
Views: 1,378
Posted By paulunderwood
Cool Only x^2-2^r*x-4

Based on only x^2-2^r*x-4 ...

And it's clunky:


{
tst(n,r)=local(t=lift(Mod(2,n)^r));
((n%4==1&&gcd(t^2+4,n)==1)||
(n%4==3&&gcd(t^2+8,n)==1))&&
kronecker(t^2+16,n)==-1&&
Forum: Miscellaneous Math 2021-06-21, 20:49
Replies: 17
Views: 1,378
Posted By paulunderwood
Lightbulb base 3 variant

This time based on x^2-3^r*x+-9 ...

n%4==1:


{
tst(n,r)=local(t=lift(Mod(3,n)^r));
gcd(t^2-3,n)==1&&gcd(t^2-9,n)==1&&
kronecker(t^2-4*9,n)==-1&&
Mod(3,n)^(n-1)==1&&
Forum: Miscellaneous Math 2021-06-21, 16:48
Replies: 17
Views: 1,378
Posted By paulunderwood
Smile 1+2 selfridges

Based on x^2-2^r*x+-4 ...

If n%4==1 then:


{
tst(n,r)=local(t=lift(Mod(2,n)^r));
gcd(t^2-4,n)==1&&
kronecker(t^2-16,n)==-1&&
Mod(2,n)^(n-1)==1&&
Forum: Miscellaneous Math 2021-06-20, 17:33
Replies: 17
Views: 1,378
Posted By paulunderwood
I have verified this for all r for all n<10^11. ...

I have verified this for all r for all n<10^11.

I will convert to GMP soon.
Forum: Miscellaneous Math 2021-06-20, 05:04
Replies: 17
Views: 1,378
Posted By paulunderwood
Thumbs up Efficent Test

The efficient test is:


{
tst(n,r)=local(t=lift(Mod(1/2,n)^r));
gcd(t^2-1,n)==1&&
gcd(t-2,n)==1&&
kronecker(t^2-4*t,n)==-1&&
Mod(2,n)^((n-1)/2)==kronecker(t,n)&&...
Forum: Miscellaneous Math 2021-06-20, 00:22
Replies: 17
Views: 1,378
Posted By paulunderwood
Cool Extra gcd

This test looks good:


{
tst(n,r)=local(t=lift(Mod(2,n)^r));
gcd(t^2-1,n)==1&&
gcd(2*t-1,n)==1&&
kronecker(1-4*t,n)==-1&&
Mod(2,n)^((n-1)/2)==kronecker(t,n)&&...
Forum: Miscellaneous Math 2021-06-19, 08:02
Replies: 17
Views: 1,378
Posted By paulunderwood
Restricted domain variation

Here I test over

x^2-x+2^r where kronecker(1-4*2^r,n)==-1
x^2-x-2^r where kronecker(1+4*2^r,n)==-1

If r is even this is the same as:

2^(n-1)==1 (mod n)
x^((n+1)/2)==1 (mod n,...
Forum: Hardware 2021-06-13, 23:09
Replies: 197
Views: 26,928
Posted By paulunderwood
1. Check NUMA is on in BIOS whatever that is!...

1. Check NUMA is on in BIOS whatever that is! :smile:

2,
Installation:
sudo yum install numactl

To see the memory map:
numactl -H
To run yr_prog entirely binded to MCDRAM:
numactl -m 1...
Forum: Hardware 2021-06-13, 22:35
Replies: 197
Views: 26,928
Posted By paulunderwood
This is way out of my depth, but do you have a...

This is way out of my depth, but do you have a good reason for not using numactl in flat-mode? Have you tried timings using it?
Forum: sweety439 2021-06-13, 21:21
Replies: 11
Views: 191
Posted By paulunderwood
You have Windoze Install on it Sun's free...

You have Windoze
Install on it Sun's free Virtual Box
In Virtual Box install Ubuntu
In Ubuntu install the latest multi-core Primo
Profit

That old mono-processor software will not get you...
Forum: Hardware 2021-06-13, 03:11
Replies: 197
Views: 26,928
Posted By paulunderwood
1, is bad news. The access to the DIMMs must be...

1, is bad news. The access to the DIMMs must be much slower than the MCDRAM -- an expensive lesson. With them, do you have a great 68-instances P-1 machine? See the table on this page...
Forum: Miscellaneous Math 2021-06-11, 23:15
Replies: 17
Views: 1,378
Posted By paulunderwood
[n,P,Q,R]=[1162349, 2335, 1, 2234] fools tst4(). ...

[n,P,Q,R]=[1162349, 2335, 1, 2234] fools tst4().

I have now revised the test; I insist that gcd(Q^2-1,n)==1 and gcd(R^2-1,n)==1 as well. :grin:

...
Forum: Lounge 2021-06-11, 09:41
Replies: 396
Views: 56,624
Posted By paulunderwood
Like a fool I answered my phone. "This is your...

Like a fool I answered my phone. "This is your service provider, your router has been hacked and I am here to fix it", said the woman with an Indian accent. Step-by-step instructions to install...
Forum: Hardware 2021-06-10, 23:09
Replies: 197
Views: 26,928
Posted By paulunderwood
I run Debian Buster on my Phi. Forget...

I run Debian Buster on my Phi. Forget multithreading on these beasts. 64 instances is king for mine, although I am running 4 Primo instances with its 256 threads. I don't know how Ernst's code copes.
Forum: Miscellaneous Math 2021-06-10, 20:57
Replies: 17
Views: 1,378
Posted By paulunderwood
Well that was a lot of BS maths. I...

Well that was a lot of BS maths.



I have tested (with strong kroneckers and gcd(P,n)==1 and gcd(Q^2-R^2,n)==1) for Q=1 up to n < 10^6 and for all Q for n up to 1.8*10^4 with Pari/GP. When I get...
Forum: Miscellaneous Math 2021-06-09, 18:39
Replies: 145
Views: 8,561
Posted By paulunderwood
:dnftt:

:dnftt:
Forum: Miscellaneous Math 2021-06-08, 00:13
Replies: 17
Views: 1,378
Posted By paulunderwood
What is wrong with this argument? Let: ...

What is wrong with this argument?

Let:
x^2-P*x+Q=0
y^2-P*y-Q=0
s^2-P*s+R=0
t^2-P*t-R=0

Then:
x^2+y^2-P*(x+y)=0
Forum: Miscellaneous Math 2021-06-07, 07:35
Replies: 17
Views: 1,378
Posted By paulunderwood
tst4(9809, 577, 27, 171) fails, but if I add the...

tst4(9809, 577, 27, 171) fails, but if I add the remedy gcd(P,n)==1 all is good.
Forum: Miscellaneous Math 2021-06-06, 10:53
Replies: 17
Views: 1,378
Posted By paulunderwood
I have not yet found a counterexample to the...

I have not yet found a counterexample to the previous test.

I now propose a more general test:

{
tst(n,P,Q_i,Q_j)=
kronecker(P^2-4*Q_i)==-1&&
kronecker(P^2+4*Q_i)==-1&&...
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