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Old 2020-10-24, 10:05   #34
piforbreakfast
 
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Quote:
Originally Posted by kriesel View Post
Go bigger if it won't get in the way of other things. And make day and night values the same to avoid restarts of stage 2 when the limits change with the time of day.

George's example is for 6GB. It will use 20+GB on 100M exponents if it's available.

For such questions, the included documentation is useful. From readme.txt:
Code:
Daytime and nighttime P-1/ECM stage 2 memory
--------------------------------------------

On occasion, you may be assigned an exponent that needs P-1 factoring prior to running a
primality test.  Or you might have chosen to do P-1 or ECM work (possibly because you do
not want to devote disk space for large PRP files).  In these situations, the program can
do stage 2 slightly more effectively if it is given more memory to work with.  However,
if you let the program use too much memory then the performance of ALL programs will suffer
due to thrashing.  

That is, most of the time this setting is not used and even with minimal settings the program
will work just fine.  Should you decide to change these settings, how do you choose intelligently?
Below are some steps you might take to figure this out:

1)  Be conservative.  It is better to set the memory too low than too high.  Setting the value
too high can cause thrashing which slows down all programs.

2)  Start with how much memory is installed in your machine.  Allow a reasonable amount of memory
for the OS and whatever background tasks you run (say 0.5 to 2.0GB).  This represents the maximum
value you should use.  The program won't let you enter more than 90% of installed memory.

3)  Assuming you run your machine 24 hours a day, what hours of the day do you not use your computer?
Make these your nighttime hours and let the program use a lot of memory during these hours.  But
reduce this value if you also run batch jobs at night.

4)  Factor in the information below about minimum, reasonable, and desirable memory amounts for some
sample exponents.  If you choose a value below the minimum, that is OK.  The program will simply skip
stage 2 of P-1 factoring.

    Exponent    Minimum        Reasonable    Desirable
    --------    -------        ----------    ---------
    100000000     0.2GB          0.7GB         1.1GB
    333000000     0.7GB          2.1GB         3.5GB

For example, my machine is a dual-processor with 8GB of memory.  I guess Windows and the programs I
normally use can survive on 2GB of memory.  Thus, I set memory to 6.0GB.  This is my nighttime setting.
During the day, I run more programs, so I set memory to 1.5GB.  I can always stop prime95 if it is
doing stage 2 P-1 factoring and I suspect memory is thrashing.  More casual users might want to set the
daytime memory to 0.5GB so they never have to worry about prime95 impacting system performance.
Should I go ahead and try a higher memory setting?
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Old 2020-10-24, 15:51   #35
Uncwilly
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Quote:
Originally Posted by piforbreakfast View Post
Should I go ahead and try a higher memory setting?
Can you give us the spec on how much RAM you have, what type, and again any data about the CPU.

Assuming that you have at least 1 GB of RAM to spare, yes, set it to 1
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Old 2020-10-24, 17:50   #36
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Check whether your current settings and exponents are reaching the bounds required to retire the P-1 task from the database. Repeated P-1 with increasing bounds is wasteful. Aim to finish the task with sufficiently high bounds, so no one else has to. If that is not practical, then P-1 is not a good work type for the system involved. Note though that lower bounds than the guidelines may be offset by higher TF than usual guidelines in some exponent cases in the database.

See https://www.mersenneforum.org/showth...129#post531129
and https://www.mersenneforum.org/showpo...7&postcount=23
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Old 2020-10-25, 02:36   #37
piforbreakfast
 
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Quote:
Originally Posted by Uncwilly View Post
Can you give us the spec on how much RAM you have, what type, and again any data about the CPU.

Assuming that you have at least 1 GB of RAM to spare, yes, set it to 1
It looks like I have 16GB of RAM, so I changed it to 1. Should I go higher?

Last fiddled with by piforbreakfast on 2020-10-25 at 02:44
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Old 2020-10-25, 15:22   #38
Runtime Error
 
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Quote:
Originally Posted by piforbreakfast View Post
It looks like I have 16GB of RAM, so I changed it to 1. Should I go higher?
Yes. The only part that uses a significant quantity of memory is the second half of the P-1 factoring attempt that is made before a primality test. (RAM speed is very important for big FFTs but quantity doesn't matter other than through its correlation with the number of sticks for RAM channels.) If your primary goal is to PRP, then you will probably never even notice the brief window when P-1 uses it's max allocation. Turn it up!!!

Last fiddled with by Runtime Error on 2020-10-25 at 15:23
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Old 2020-10-26, 02:58   #39
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Quote:
Originally Posted by piforbreakfast View Post
I guess I jumped in the deep end from the start because I've got way too much time on my hands and I've always been fascinated by numbers. I got really bored in sixth grade and memorized pi to 200 decimal places. I still get really bored, almost 40 years later, so here I am.
Welcome!

Some people count sheep if they can't sleep. But sheep = lamb chops = hunger, not sleep. So in high school, I decided to count pi instead. When I couldn't sleep, I'd go 3,1,4,1,5,9, etc., instead of 1,2,3,4,5, and so on.

On some nights, I got up to the Feynman point: https://en.wikipedia.org/wiki/Six_nines_in_pi . On really sleepless nights, I counted up to 900-950 digits, but I don't think I ever went beyond the 1,000 digit mark.

College soon came around, and those nights spent counting pi were replaced by nights thinking of finals, projects, internships, and bills. It's been well over a decade since I last counted pi, but reading this made me curious to see how much pi I had in my long term memory. The answer was 110 digits. Strangely enough, I remember the string "5058223172", but have no idea what numbers come immediately before or after that without looking it up.
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Old 2020-10-26, 11:35   #40
piforbreakfast
 
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Quote:
Originally Posted by Runtime Error View Post
Yes. The only part that uses a significant quantity of memory is the second half of the P-1 factoring attempt that is made before a primality test. (RAM speed is very important for big FFTs but quantity doesn't matter other than through its correlation with the number of sticks for RAM channels.) If your primary goal is to PRP, then you will probably never even notice the brief window when P-1 uses it's max allocation. Turn it up!!!
I just changed daytime and nighttime RAM to 4GB. I hope my processor doesn't start smoking. Prime95 is the only thing my computer is doing, so I'm guessing this won't be a problem.
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Old 2020-10-27, 08:03   #41
piforbreakfast
 
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Quote:
Originally Posted by piforbreakfast View Post
I just changed daytime and nighttime RAM to 4GB. I hope my processor doesn't start smoking. Prime95 is the only thing my computer is doing, so I'm guessing this won't be a problem.

What the heck, I just bumped it up to 7GB...
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Old 2020-10-27, 08:22   #42
piforbreakfast
 
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Quote:
Originally Posted by Uncwilly View Post
Does your gaming machine have a GPU and if so what kind? (So we can recommend the right software to run on it.

Also, make sure that you are using the latest version of Prime95. v30 available here:
https://www.mersenneforum.org/showthread.php?t=25823
Quote:
Originally Posted by kriesel View Post
Welcome, and condolences. GIMPS can be a helpful distraction at difficult times. (Has for me, repeatedly!)

Contributing effort at any level is welcome.
You may find something useful in the new participant thread or other parts of https://mersenneforum.org/showthread...922#post521922
Prime95 v30.3b6 is also the default version for download at https://www.mersenne.org/download/
Gpu software depends on both the hardware and computation type(s) planned; see http://www.mersenneforum.org/showpos...91&postcount=2
I was just going back and re-reading previous posts, and I realized I'm not sure how to tell (since someone asked me) if there is actually a graphics card installed in this machine, although I'm guessing that there is, because included in the setup equipment were CDs labeled "graphics driver and utility" and Intel Motherboards Drivers and Utilities. But as far as I can tell there is not an actual disk drive where I can insert the disks. Should I have some kind of external device? And if I can figure out how to load these disks into my computer, am I correct in assuming that they will also help my overall processor operation?
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Old 2020-10-27, 09:27   #43
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Quote:
Originally Posted by piforbreakfast View Post
I was just going back and re-reading previous posts, and I realized I'm not sure how to tell (since someone asked me) if there is actually a graphics card installed in this machine,
Windows GPU-Z
Linux command prompt: lspci -nnk | grep -i VGA -A2
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Old 2020-10-27, 10:00   #44
piforbreakfast
 
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Originally Posted by moebius View Post
Windows GPU-Z
Linux command prompt: lspci -nnk | grep -i VGA -A2
I downloaded GPU-Z and this came up. So it looks like I do have a graphics card installed?
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