JJSieve Discussion

[Joe O]

instead of SPQR.. perhaps you could call it PQRS as in lmo-PQRS-tuv

SPQR was emblazoned on the standards of the Roman legions and was used by the Roman republic and the Roman empire. Caesar refers to Julius Caesar. It is the acronym for Senatus PopulusQue Romanus which roughly translates into The Senate and People of Rome, or the Senate and the Roman people This started to be used since a very early stage of the Roman republic, and later continued to be used during the Roman empire. As such, it appears in most of the famous monuments and documents. A fine example of this is the Arch of Titus built around 81 AD to honor Titus and his father the Emperor Vespasian. It is also used in Trajan's Column which was built in 113 AD to pay homage to Emperor Trajan.

For extra credit please identify: "Quis custodet ipsos custodes" and/or "Moriture te salutamus".

ps did you mean lmno-PQRS-tuv?

[ShoeLace]

S

ps did you mean lmno-PQRS-tuv?

yes.. i forgot the n

[Greenbank]

For extra credit please identify: "Quis custodet ipsos custodes" and/or "Moriture te salutamus".

My Latin is very rusty, but the first one is easy. "Who watches the watchmen?" (Or polices the police, or guards the guards). It's usually custodiet if I remember correctly.

Second one, hmm, Death, salute...ah yes, the gladiatorial greeting before a fight.. "We who are about to die salute you."

[Joe O]

My Latin is very rusty, but the first one is easy. "Who watches the watchmen?" (Or polices the police, or guards the guards). It's usually custodiet if I remember correctly.

Second one, hmm, Death, salute...ah yes, the gladiatorial greeting before a fight.. "We who are about to die salute you."

Correct on both, and the form of the verb as well.

[Joe O]

Wine is bad!!! At least in my experience:

340 kp/s top for JJSieveSSE2 under Wine
500 kp/s top for proth_sieve_sse2

Setup:
Linux 2.6, Athlon 64 3000+, 1 GB Dual Channel DDR
Currently sieving @ 1062.3 T

Unfortunately, comparing the "top" reported speed for proth_sieve will lead to inaccuracies. There were two loops in it, one for the processing and one for the reporting. Because of the relative size of the controlling variables, there was a 5 5 6 beat pattern in the reported speeds. you have to take the average of 16 consecutive reported speeds to get the true speed.

[ShoeLace]

there was a 5 5 6 beat pattern in the reported speeds. you have to take the average of 16 consecutive reported speeds to get the true speed.

thats a useful thing to know.. cheers

[royanee]

Unfortunately, comparing the "top" reported speed for proth_sieve will lead to inaccuracies. There were two loops in it, one for the processing and one for the reporting. Because of the relative size of the controlling variables, there was a 5 5 6 beat pattern in the reported speeds. you have to take the average of 16 consecutive reported speeds to get the true speed.

hehe, then I'll be exact:

n=49
348.47 with a standard deviation of 41.56
465.66 with a standard deviation of 18.99

If anything, the second set of number was under the higher load, because I let the JJsieve go off on it's lonesome, until I realized how slow it was going. When I started proth_sieve, I went back to using the computer, so the averages dropped from ~494 to the ~466 shown.

[Zahmekoses]

Hi there

Just one question from my side (or maybe reporting of a bug)...

I'm using JJSieveSSE2 under WinXP Home on an Mobile AMD Athlon XP64 4000+, sieving for Riesel Sieve, and noted that my jjsieve client does not seem to accept the "-i" switch.

When I start the program with "JJsieveSSE2.exe -i 1000000 -vv" it writes its progress every 67'000'000 into the RieselStatus.dat and not, as it is suggested by the switch, every 1'000'000. I've tried a bit around and altered the number behind the -i to numbers from 500'000 to 10'000'000, I even stopped using the -i switch, but everytime the client sieved approx. 67'000'000 before he gives me a line like "pmin=1634XXXXXXXXXXX @ 197kp/s".

Is it my fault that it does not work (maybe bad karma? ;o)) or have others also experienced this behaviour of the client?
It's not the end of the world, but I just wanted to point that one out

Regards,
-Zahme

[vjs]

I think Joe may have actually removed or reduced the reporting. There was a point where chuck was talking about the code and when to get the client to report a speed and p.

I'd test it with an sob dat first if it doesn't work I think that function was removed. Or at least it doesn't work as suggested.

I can't recall correctly but I think it had something to do with the prime generation??? Perhaps Chuck can step in and answer.

[Joe O]

Hi there

Just one question from my side (or maybe reporting of a bug)...

I'm using JJSieveSSE2 under WinXP Home on an Mobile AMD Athlon XP64 4000+, sieving for Riesel Sieve, and noted that my jjsieve client does not seem to accept the "-i" switch.

When I start the program with "JJsieveSSE2.exe -i 1000000 -vv" it writes its progress every 67'000'000 into the RieselStatus.dat and not, as it is suggested by the switch, every 1'000'000. I've tried a bit around and altered the number behind the -i to numbers from 500'000 to 10'000'000, I even stopped using the -i switch, but everytime the client sieved approx. 67'000'000 before he gives me a line like "pmin=1634XXXXXXXXXXX @ 197kp/s".

Is it my fault that it does not work (maybe bad karma? ;o)) or have others also experienced this behaviour of the client?
It's not the end of the world, but I just wanted to point that one out

Regards,
-Zahme

No, not your fault. The reporting interval has been changed to be in sync with the processing interval. If you increase the number to 100'000'000 you will see that it reports every 135'000'000 or thereabouts. The open question is how to change the description of the -i switch. should we change it to a multiple ie 1x, 2x, 3x, etc. or just drop it. Of all the people from all the projects that we talked to, only one was using it and he was happy with the new number. He had been increasing it to lower the disk activity. This interval also controls how often the pmin checkpoint is written to the status file.

[hhh]

I just had a (possibly useless) idea.
I have two instances of prothsieve running on my hyperthreaded P4. So, I had to split my range in two halfs.
I'm sure it is not difficult to implement BACKWARDS sieving; so one client could easily take advantage of a HT/Dual Core CPU. It starts just at the beginning and the end of the range at the same time.
Don't know if such a feature would be apreciated, though. With a switch, perhaps? Yours, H.

[Mystwalker]

I posed such an idea some months (or even years?) ago. IIRC, there was no result. The problem is that the code has to be rewritten to allow this, which will be a lot of hassel.

On a HT machine, I wouldn't use 2 proth_sieve instances anyway. Instead, one proth_sieve and some other client (e.g. PRPing or P-1 factoring) is more efficient in my experience.

[hhh]

On a HT machine, I wouldn't use 2 proth_sieve instances anyway. Instead, one proth_sieve and some other client (e.g. PRPing or P-1 factoring) is more efficient in my experience.

I believe this is an urban legend (which I helped to spread, I confess).
I did some tests some time ago, and 2xproth just doubles my output.
2xPRP gives half the speed for each, and proth+PRP doesn't change the speed of proth, but gives half the speed for PRP.
So, if I do one month proth+PRP, it is the same thing as half a month PRP (at double speed) and half a month 2xproth.
I tried to put two instances of P-1 together, too, and it didn't wark any better (this idea was btw my first post at mersenneforum).

Yours H.

[vjs]

I think the major advantage of running the sieve or PRP along side P-1 is the somewhat fixed low memory consumption. Generally allowing more memory for P-1 stage2 on the second processor.

[Mystwalker]

I did some tests some time ago, and 2xproth just doubles my output.

That's odd - my results were somewhat different. I don't remember exact figures, but using two instances increased throughput by 40-60% in my testings with my P4.
When running a single proth_sieve and then starting e.g. PRPing, sieving speed didn't halve, but dropped by maybe 30-40%...

Unfortunately, I can retest it now, because the P4 system isn't stable anymore since 2-3 weeks. When stressing the CPU, it reboots after maybe 30 minutes.

[hhh]

When I'm running one proth-sieve and starting something else, the speed of proth isn't affected. So I have the choice between another proth at the same speed or one prp at half speed.
The latter doesn't change from sieving 2 times and then only PRPing.
With P-1, I didn't try out.
Yours H.

[Mystwalker]

When I'm running one proth-sieve and starting something else, the speed of proth isn't affected.

That's interesting.
I'm very confident you know the difference, but I have to ask in order to be sure:
You really have a HT system and no dual-core, don't you?

[hhh]

I know the difference, but: it's my office pc, so I didn't check quite well. I remember enabeling HT in the bios, but that doesn't mean anything.
Linux tells me:
proc 0
Genuine Intel
family 15
model 4
P4 3.00GHz
stepping 1
cache size 1024KB
etc.
in the flags there is "ht"

Some proc freak might warp in here.
H.

[dudlio]

I just got a dual-core Athlon so I'm interested in running 2 instances and getting my cpu usage up to 100%. I reserved a second range, copied my sieveA folder to a new location, cleared out all the old config data and input the new range.

Then I fire up JJSieveSSE2.exe. My cpu usage jumps to 100% with 2 instances running BUT the second instance is still using the old range!

Any tips on running 2 ranges simultaneously? It's not working for me.

[dudlio]

Aha, the SieveB folder is for dual-core procs. Nice, it works. I can sieve@1600kps now. That's sick...

[Death]

Hi everybody )))
I'm back now!!!!

Greetz 4 all who remember me, howdo folks?

And now the problem ((((

cant start jjsieve under 2k pro
both sse and cmov version show this

Popup window: JJsieveSSE2.exe - application error : command at address "0x77f87eeb" call the memory at address "0x00000034". memory can't be "read".

[Death]

OMG

i forget to put sob.dat at directory and it just CRASH!!
now it works... (SSE version crash too, instead of saying smth like "no sse - i'm quit")

[Death]

and other question

does it goes right when shows 180k at p4 3.2 GHz ?
combined sieve 666000g range

[hhh]

Yes, that looks right to me. However, if you have hyperthreading enabled, you should run a second sieve client. Just make another folder, and run it on another range.