The best work for my CPU
 

As I understand it, the "calculation-code" in Prime95 are written in Assembly-language. Doesn't this mean that you have to write specific code for each CPU there is?

I'm also under the impression that some CPUs are better for calculation A, some are better for B - relative to their calculation speed, of course.

So I wonder what work is best fit for my own CPU. I have a i5-2500, not over-clocked...

I'm pretty sure the assembly language involved here is x86. This is not CPU-specific, and covers both Intel and AMD CPUs. While Prime95 is updated as CPUs come out to take advantage of new features (e.g. SSE2, AVX), I think the core code runs on every x86/x86-64 CPU.

For the practical results of how Prime95 runs on different CPUs, see [URL="http://www.mersenne.ca/throughput.php"]mersenne.ca's CPU throughput calculator[/URL]. E.g. [URL="http://www.mersenne.ca/throughput.php?cpu1=Intel%28R%29+Core%28TM%29+i5-2500K+CPU+%40+3.30GHz%7C256%7C6144&mhz1=3300&cpu2=AMD+A8-3850+APU+with+Radeon%28tm%29+HD+Graphics%7C1024%7C0&mhz2=2900"]this comparison[/URL] of your CPU and an AMD CPU is an example of how Intel CPUs run FFTs (LL, P-1, etc.) better, and AMD CPUs run TF better (relatively).

Your i5-2500 is probably best suited to FFTs - P-1, DC, or LL. For GIMPS, that's all I'd run on a CPU, since GPUs are so much better at TFing.

[QUOTE=Mini-Geek;344125]I'm pretty sure the assembly language involved here is x86. This is not CPU-specific, and covers both Intel and AMD CPUs. While Prime95 is updated as CPUs come out to take advantage of new features (e.g. SSE2, AVX), I think the core code runs on every x86/x86-64 CPU.

For the practical results of how Prime95 runs on different CPUs, see [URL="http://www.mersenne.ca/throughput.php"]mersenne.ca's CPU throughput calculator[/URL]. E.g. [URL="http://www.mersenne.ca/throughput.php?cpu1=Intel%28R%29+Core%28TM%29+i5-2500K+CPU+%40+3.30GHz%7C256%7C6144&mhz1=3300&cpu2=AMD+A8-3850+APU+with+Radeon%28tm%29+HD+Graphics%7C1024%7C0&mhz2=2900"]this comparison[/URL] of your CPU and an AMD CPU is an example of how Intel CPUs run FFTs (LL, P-1, etc.) better, and AMD CPUs run TF better (relatively).

Your i5-2500 is probably best suited to FFTs - P-1, DC, or LL. For GIMPS, that's all I'd run on a CPU, since GPUs are so much better at TFing.[/QUOTE]

Thanks!

Yeah I think I read somewhere that GPUs have become much better than CPUs for TF. So, then I think it is weird that the "automatically" assignment from GIMPS (Prime95) just gave me TF assignments.

[QUOTE=Unregistered;344126]Thanks!

Yeah I think I read somewhere that GPUs have become much better than CPUs for TF. So, then I think it is weird that the "automatically" assignment from GIMPS (Prime95) just gave me TF assignments.[/QUOTE]

How many hours a day did you tell the program that it was likely to run? Also, are you letting it run on all cores or only 1?

[QUOTE=Uncwilly;344128]How many hours a day did you tell the program that it was likely to run? Also, are you letting it run on all cores or only 1?[/QUOTE]

24 h/day. It will run on 4/4 cores. :-)

It's a computer that I don't use for anything else.

[QUOTE=Mini-Geek;344125]
Your i5-2500 is probably best suited to FFTs - P-1, DC, or LL. For GIMPS, that's all I'd run on a CPU, since GPUs are so much better at TFing.[/QUOTE]

[QUOTE=MacMagnus;344131]24 h/day. It will run on 4/4 cores. :-)
It's a computer that I don't use for anything else.[/QUOTE]

First time LLs are definitely your game.
(P-1 as necessary, and leave DCs to the slower guys).

If there is a decent GPU with your i5, join in the effort to ensure that every exponent >64M is TFed to 74. (Chalsall needs help!).

Re "Winning the lottery", 1/115000 every 3 weeks is certainly better than the norm for such things.
This applies to expos ~60M.
For a 100M digit prime, reduce your expectations by a factor of 200.
And take out some life insurance in case you are not around in 2030 AD:smile:

David

[QUOTE=Mini-Geek;344125]I'm pretty sure the assembly language involved here is x86. This is not CPU-specific, and covers both Intel and AMD CPUs. [/QUOTE]

I'm damn certain it is.
But the "non CPU specific" bit applies more to the history of hardware development than the "level" of programming.
There are things called "compilers" which occasionally ceate/modify assembler that runs on varying platforms that runs ~1/3 times as fast as I could manage (in my assembly programming prime:smile:)

D

Someone please correct me if I am wrong but is it possible that the server may assign TF just to test the CPU's reliability before giving it a LL test?

Or, it is also possible that this may be one of the symptoms of the iffy server. A few people have been noting problems of late.

Can it be because of my BIOS-setup? I sat it to "fail safe" instead of "optimal". Sounds weird if it could be this, I didn't thing the difference were that large...

[QUOTE=davieddy;344133]First time LLs are definitely your game.
(P-1 as necessary, and leave DCs to the slower guys).

If there is a decent GPU with your i5, join in the effort to ensure that every exponent >64M is TFed to 74. (Chalsall needs help!).

Re "Winning the lottery", 1/115000 every 3 weeks is certainly better than the norm for such things.
This applies to expos ~60M.
For a 100M digit prime, reduce your expectations by a factor of 200.
And take out some life insurance in case you are not around in 2030 AD:smile:

David[/QUOTE]

Alas I don't even have a separate GPU. (I'm not a gamer! :razz: )

A reduce by a factor of 200? Some lotteries have those odds, hehe.

No, I don't expect to "win". It's fun tho, doing scientific research, hehe. :smile:

[QUOTE=MacMagnus;344148]Alas I don't even have a separate GPU. (I'm not a gamer! :razz: )

A reduce by a factor of 200? Some lotteries have those odds, hehe.

No, I don't expect to "win". It's fun tho, doing scientific research, hehe. :smile:[/QUOTE]

Sounds like you'll fit in fine here.
Have you been "Lurking"?

D

[QUOTE=MacMagnus;344148]
A reduce by a factor of 200? Some lotteries have those odds, hehe.
[/QUOTE]

I know it's difficult to tell whether I'm joking or not,
but (60/360)^3 ~ 1/216 if I'm not mistaken.

I highly doubt any BIOS setting will affect the way Primenet gives you results unless your "failsafe mode" is actually underclocking your CPU beyond the need for a heatsink...

It might be that the server is over-emphasizing trial factoring. Chalsall, who seems to be the go-to guy for the GPU computing side of things, recently expressed interest in getting all the exponents trial factored to 2[SUP]75[/SUP] as opposed to the 2[SUP]74[/SUP] everyone was kind of going for. If he's asked the server to assign TF to 75 bits, then by the server's standards, TF is WAAAAAAAAAAAAAAAAAAAAAAAY behind schedule, even though we're quite far ahead as far as factoring to 74 bits goes.

[QUOTE=TheMawn;344192]Chalsall, who seems to be the go-to guy for the GPU computing side of things, recently expressed interest in getting all the exponents trial factored to 2[SUP]75[/SUP] as opposed to the 2[SUP]74[/SUP] everyone was kind of going for.[/QUOTE]
Chalsall's mouth is bigger than his stomach and brain combined.

[QUOTE=TheMawn;344138]Someone please correct me if I am wrong but is it possible that the server may assign TF just to test the CPU's reliability before giving it a LL test?[/QUOTE]

I believe you mean DC checks? If so, no I don't think so. TF will tell you nothing of cpu stability.

[QUOTE=TheMawn;344192]Chalsall, who seems to be the go-to guy for the GPU computing side of things, recently expressed interest in getting all the exponents trial factored to 2[SUP]75[/SUP] as opposed to the 2[SUP]74[/SUP] everyone was kind of going for.[/QUOTE]

I'm just one gear in a very complicated machine.

To be clear, I hope and expect that we can start going to 75 "bits" at 64M or so. But right now we're riding the wave going to 74.

[QUOTE=chalsall;344242]I'm just one gear in a very complicated machine.

To be clear, I hope and expect that we can start going to 75 "bits" at 64M or so. But right now we're riding the wave going to 74.[/QUOTE]
Incorrect.
You are just a spanner in the works of a very simple machine.

James has shown that a typical GPU could profitably TF to 75 before doing LL work.
As you agree, the limitation is currently the firepower available.

Up until 3 months ago, "we" were happily TFing everything >53M to 73 bits, and were getting comfortably ahead of the LL assignment wavefront.
This also left plenty of time for P-1, and could contemplate upping the "what makes sense" goal to 74 bits.
You argued that we were far enough ahead to do this immediately, even if the assignment front might catch up a bit before TF to 74 drew ahead again.

Despite my misgivings and BCP19's self-induced implosion, you elected (unilaterally) to "Suck it and see". Reasonable enough.

Realizing that TFing from 70 to 74 was not reaching the ~300+ per day, I suggested a "crackpot" reductio ad absurdum idea of backtracking TFto74 to 62M (thereby erasing your "TF is well ahead" argument).

You rose to the bait, and the result is farcical.

75 bits? Don't make me larf.
Maybe we can start another war in 2 years time.

David

[QUOTE=davieddy;344265]Incorrect.
You are just a spanner in the works of a very simple machine.

James has shown that a typical GPU could profitably TF to 75 before doing LL work.
As you agree, the limitation is currently the firepower available.

Up until 3 months ago, "we" were happily TFing everything >53M to 73 bits, and were getting comfortably ahead of the LL assignment wavefront.
This also left plenty of time for P-1, and could contemplate upping the "what makes sense" goal to 74 bits.
You argued that we were far enough ahead to do this immediately, even if the assignment front might catch up a bit before TF to 74 drew ahead again.

Despite my misgivings and BCP19's self-induced implosion, you elected (unilaterally) to "Suck it and see". Reasonable enough.

Realizing that TFing from 70 to 74 was not reaching the ~300+ per day, I suggested a "crackpot" reductio ad absurdum idea of backtracking TFto74 to 62M (thereby erasing your "TF is well ahead" argument).

You rose to the bait, and the result is farcical.

75 bits? Don't make me larf.
Maybe we can start another war in 2 years time.

David[/QUOTE]

Holy crap. Let's just settle down... I've been trying to make sense of the info on GPU72.com and the PrimeNet summary, but it's been a bit difficult. I feel like we lack a consolidated summary of how many exponents are at which stage (i.e., 72, 73, 74, P-1, ready for LL, LLing and first LL finished).

Looking at 60M: [LIST][*]Last week, 426 of 18,949 exponents were trial factored from 73 to 74 (and I think 6 were found to be composite). This gives 1,290 factored to 74.[*]Presently, 13,910 exponents are being LL'ed. 14,476 exponents have not had any LL-done, which leaves 566 that are in need of LL but have not had any done yet.[*]Of these 566, 153 are available for LL. This leaves 413. There are 409 assigned TF and 39 assigned P-1, and no work available in either category.[/LIST]
First off, it seems to me like the numbers aren't [I]quite[/I] adding up. Second, it seems like a LOT of the 73 bits factored are being sent out for LL tests. Third, I can't tell how many exponents have had and/or need P-1.

This is all making it seem to me like Trial Factoring isn't keeping up.

[QUOTE=TheMawn;344282]This is all making it seem to me like Trial Factoring isn't keeping up.[/QUOTE]Chris (Chasall) keeps track of what the GPUto72 throughput is. If it looks like the lead is diminishing too quickly, he will dial it back down by a bit. If it looks like TF is pulling way far ahead, he can up the bit level. It is quick for him to do.

@ Mods.
Perhaps the last few posts could be moved elsewhere (excluding "Useless Posts"), where TheMawn and MacMagnus would be most welcome to continue the discussion.

Things are getting a bit "tasty" here, and I don't think the "front door" to Mersenneforum is the best place to continue it.

D

[QUOTE]Despite my misgivings and BCP19's self-induced implosion, you elected (unilaterally) to "Suck it and see". Reasonable enough.
[/QUOTE]

You modestly omit your helpful role in "pissing off Pete". Come on! Take pride in your work!

[QUOTE=TheMawn;344282]This is all making it seem to me like Trial Factoring isn't keeping up.[/QUOTE]

We are. Just (which is how it should be -- it means we're at the perfect balance of firepower / bit-depth).

Compare [URL="http://www.mersenne.info/trial_factored_tabular_delta_30/2/60000000/"]this report[/URL] which shows over the last month we've TFed 8,963 candidates to 74 "bits", against [URL="http://www.mersenne.info/exponent_status_tabular_delta_30/1/0/"]this report[/URL] which shows that approximately 8,906 candidates were LLed once.

Currently no candidate above 62M is being assigned without being TFed to at least 74 bits, and P-1'ed "well". In addition, we're taking a few candidates in the 60M and 61M ranges to 74 bits as the situation allows.

:smile::goodposting:[QUOTE=kladner;344302]You modestly omit your helpful role in "pissing off Pete". Come on! Take pride in your work![/QUOTE]
Come back Pistol Pete - all is forgiven.

And let's drink to our enjoyment of G&S and Mozart:smile:

Cheers,
D

There we go. That's the chart I needed. That looks better.

I can understand Davieddy's anxiety as far as upping the depth to 75 bits is concerned because we clearly don't have the computing power to do that. His hostility, on the other hand...

Time will tell all things. I might have another GPU by then so who knows? :)

[QUOTE=davieddy;344312]:smile::goodposting:
Come back Pistol Pete - all is forgiven.

And let's drink to our enjoyment of G&S and Mozart:smile:

Cheers,
D[/QUOTE]

Aye! I hoist a virtual glass in your general direction. Virtual, because I'm trying to see how I do without mind-altering substances, but the thought is there.

[QUOTE=TheMawn;344354]
I can understand Davieddy's anxiety as far as upping the depth to 75 bits is concerned because we clearly don't have the computing power to do that. His hostility, on the other hand...
[/QUOTE]
Hostile?
[B]MOI?[/B]

[url=http://www.youtube.com/watch?v=Uc-9QV9H_VU] Some of my best friends have flown to Barbados[/url]

[QUOTE=TheMawn;344354]Time will tell all things. I might have another GPU by then so who knows? :)[/QUOTE]
Steady on old man.
[url=http://www.youtube.com/watch?v=owq7hgzna3E]Walk don't run[/url]

D

[QUOTE=TheMawn;344354]His hostility, on the other hand...
[/QUOTE]

I thought I might be mellowing in my old age.

[QUOTE=davieddy;344265]Incorrect.
You are just a spanner in the works of a very simple machine.

James has shown that a typical GPU could profitably TF to 75 before doing LL work.
As you agree, the limitation is currently the firepower available.

Up until 3 months ago, "we" were happily TFing everything >53M to 73 bits, and were getting comfortably ahead of the LL assignment wavefront.
This also left plenty of time for P-1, and could contemplate upping the "what makes sense" goal to 74 bits.
You argued that we were far enough ahead to do this immediately, even if the assignment front might catch up a bit before TF to 74 drew ahead again.

Despite my misgivings and BCP19's self-induced implosion, you elected (unilaterally) to "Suck it and see". Reasonable enough.

Realizing that TFing from 70 to 74 was not reaching the ~300+ per day, I suggested a "crackpot" reductio ad absurdum idea of backtracking TFto74 to 62M (thereby erasing your "TF is well ahead" argument).

You rose to the bait, and the result is farcical.

75 bits? Don't make me larf.
Maybe we can start another war in 2 years time.

David[/QUOTE]
No implosion here David, I just got tired of the diarrhea that spews from your mouth daily and decided I could go someplace nicer. Since my electric bill used to rival your monthly bar bill (4 figures, really??), I figured cutting 66% of it off was a good choice and gee, 2 months went by without your mouth. I think it was well worth it myself, more money in my pocket and less need of those hip-waders.

That sound like a rational choice to me, Pete. Good to see you here. I'm glad you stopped by.

I've taken over Pete's workload :smile:

[QUOTE=Chuck;344810]I've taken over Pete's workload :smile:[/QUOTE]

Good on ya, mate! :grin:

[QUOTE=bcp19;344758]Since my electric bill used to rival your monthly bar bill (4 figures, really??)...[/QUOTE]
The Chancellor of the Exchequer is trying to get me into that territory.
Apparently he was a pupil at St Paul's when I was teaching physics/math there.

[url=http://www.youtube.com/watch?v=R7llu2aQRSQ]Anyways[/url]

D

[QUOTE=bcp19;344758]Since my electric bill used to rival your monthly bar bill (4 figures, really??), I figured cutting 66% of it off was a good choice and gee, 2 months went by without your mouth.[/QUOTE]
References to excrement omitted: [url=http://www.youtube.com/watch?v=xoW3bqnr7tw]let's ride above the mess[/url]

A competition to see who can reduce their bills the most sounds almost as exciting as Aramis and Uncwilly trading things in the 100M digit zone.

D

[QUOTE=Chuck;344810]I've taken over Pete's workload :smile:[/QUOTE]
You mean 37M expos to 69 bits?

Now that is what I would describe as really urgent and useful.

[QUOTE=davieddy;345814]You mean 37M expos to 69 bits?

Now that is what I would describe as really urgent and useful.[/QUOTE]

Hard up for something nasty to say, are we?

[QUOTE=davieddy;345814]You mean 37M expos to 69 bits?

Now that is what I would describe as really urgent and useful.[/QUOTE]

No; I mean I am turning in the same number of GHz-days/day. I am using "Let GPU72 decide" assign the workload.

[QUOTE=kladner;345854]Hard up for something nasty to say, are we?[/QUOTE]You know I'm naturally good-natured and mild-mannered.

[QUOTE=Chuck;345896]No; I mean I am turning in the same number of GHz-days/day. I am using "Let GPU72 decide" assign the workload.[/QUOTE]
Now that is a seriously misguided idea.

I'm getting sick of hearing Davieddy look for the most obscure ways to take cracks at Chalsall.

[QUOTE]Now that is a seriously misguided idea[/QUOTE]

[QUOTE=TheMawn;346080]I'm getting sick of hearing Davieddy look for the most obscure ways to take cracks at Chalsall.[/QUOTE]
You seem to be a bit short of staying power.
Chris and I don't really hate each other, it's just that his thinking is screwed up big time.
PM me for more detail!

D

[QUOTE=davieddy;346114]Chris and I don't really hate each other, it's just that his thinking is screwed up big time. PM me for more detail!

D[/QUOTE]

David might be correct. On the other hand, he might not be....

[QUOTE=davieddy;346114]Chris and I don't really hate each other, it's just that his thinking is screwed up big time.[/QUOTE]
[QUOTE=chalsall;346460]David might be correct. On the other hand, he might not be....[/QUOTE]
Indeed.
We might really hate each other.

[QUOTE=chalsall;346460]David might be correct. On the other hand, he might not be....[/QUOTE]

You say David might be correct.

He says "your thinking is screwed up big time"

So the question is: is it when you say he's correct?

Luigi :smile:

[QUOTE=ET_;346510]So the question is: is it when you say he's correct?

Luigi :smile:[/QUOTE]

It's a little more complicated than that...

I was once asked (on a different forum) "Do you enjoy fighting against unarmed combatants?

"No" was my answer....

I do, but only if my arm are tied behind my back.

[QUOTE=firejuggler;346556]I do, but only if my arm are tied behind my back.[/QUOTE]

What about your brain? How do you tie that behind your back? 8-)

Maybe the :fight: can be moved to a better thread.

[QUOTE=Uncwilly;346587]Maybe the :fight: can be moved to a better thread.[/QUOTE]

What better thread is there "here and now" for a good-old-fight?

Come on, don't you remember the good old days, where men were men and the goats were fearful?

[QUOTE=chalsall;346588]Come on, don't you remember the good old days, where men were men and the goats were fearful?[/QUOTE]My goat-shagging capacity has taken a bit of a bashing recently.

I don't enjoy fighting unarmed combatants, and I tell you why: few of them beat me most of the time, and that is freaking painful (mostly psychically painful, but physically too, sometimes) :razz:... (over 12 years of my life spent in a [URL="http://en.wikipedia.org/wiki/Dojo"]dojo[/URL]).

Who scared MacMagnus off?

[QUOTE=Unregistered;357884]Who scared MacMagnus off?[/QUOTE]

Who is MacMagnus? Davieddy?

[QUOTE=kladner;357910]Who is MacMagnus? Davieddy?[/QUOTE]

The OP.
He had an i5 which he intended to devote full-time to GIMPS.

Davieddy recommended first time LL, then proceeded to fight off 5 men with his brain tied behind his back.

[QUOTE=Unregistered;357948]Davieddy recommended first time LL, then proceeded to fight off 5 men with his brain tied behind his back.[/QUOTE]

His brain would probably work better if it wasn't tied behind his back but set snugly inside his skull.

What does the fox say?
 

[QUOTE=TheMawn;357970]His brain would probably work better if it wasn't tied behind his back but set snugly inside his skull.[/QUOTE]
No, Foetus Boy.
He is a master of thinking laterally whilst out of his box.

Hello, Ginger! Back from Holiday?

Maybe a difficult reference...

[QUOTE=TheMawn;359956]Hello, Ginger! Back from Holiday?[/QUOTE]

[QUOTE=TheMawn;359969]Maybe a difficult reference...[/QUOTE]
Well I don't expect profundity from you.
This is my take on it:
"Back from Holiday?" was a rhetorical euphemism.
"Ginger" could either refer to the fox, or one of Malcolm Tucker's favorite put downs, as is "Foetus Boy".
[URL]http://www.youtube.com/watch?v=DaMb-5w-V0Y[/URL]

Am I missing something?