mfaktc: a CUDA program for Mersenne prefactoring - Page 254

James Heinrich · 2017-12-12, 03:19

I've heard of MISFIT but never used it. Tell me what needs to be changed to the API for my site and I'll make it work.

bayanne · 2017-12-12, 12:03

I finally managed to get mfaktc running on my Mac, with a lot of kind assistance from TheJudger. He asked me to post the method here, in case there are any other Mac users who wished to run TF on their Mac using the GPU.
I am running an iMac using Mac OSX 10.11.6 El Capitan which is running an Nvidia GeForce GTX 775M.

1. Download Xcode and install
2. Download Cuda 8.0 Toolkit (version 9.0 is only for OSX 10.12 and later) and install
3. Download mfaktc-0.21.tar.gz and unpack and place the folder on your desktop
4. You then need to modify the Makefile which is in the src subdirectory as follows

Change from

Code:

CFLAGS = -Wall -Wextra -O2 $(CUDA_INCLUDE) -malign-double CFLAGS_EXTRA_SIEVE = -funroll-all-loops

to

Code:

CFLAGS = -Wall -Wextra -O2 $(CUDA_INCLUDE) CFLAGS_EXTRA_SIEVE =

You have to remove/comment the line which contains

Code:

NVCCFLAGS += --generate-code arch=compute_11,code=sm_11

because CUDA 8 completely dropped support for the first gen CUDA capable GPUs (e.g. Geforce 8000, 9000 and 200 series).

You may want to add

Code:

NVCCFLAGS += --generate-code arch=compute_60,code=sm_60 # CC 6.x GPUs will use this code

which enables code generation for the current Pascal series GPUs (e.g. Geforce 1000 series).

nvcc is located in a different location than expected by the makefile, thus /usr/local/cuda/bin so you would need to define the path with the following statement:

export PATH=/usr/local/cuda/bin${PATH:+:${PATH}}
export DYLD_LIBRARY_PATH=/usr/local/cuda/lib${DYLD_LIBRARY_PATH:+:${DYLD_LIBRARY_PATH}}

You also need to advise the makefile of the path to lcudart so the following needs to be added to the start of the Makefile

# where is the CUDA Toolkit installed?
CUDA_DIR = /usr/local/cuda
CUDA_INCLUDE = -I$(CUDA_DIR)/include/
CUDA_LIB = -L$(CUDA_DIR)/lib/

This may already been in the makefile, in which case amend /lib64/ to /lib/

5. Now open Terminal and cd to the src subdirectory and then type

make clean
make

This should then produce a file mfaktc.exe in the top directory of mfaktc-0.21

6. Now run

./mfaktc.exe in Terminal which will run a short selftest. If it reports no problems, it will tell you there is nothing to do.

Then run

./mfaktc.exe –st which will run a longer selftest.

If this completes the selftest without a single error, then it is time to get some real work.

7. The file mfaktc.ini contains the settings, and you need to amend V5UserID
and Computer ID to those that you intend to use.

8. You then need to grab some exponents to test, from either the Manual Testing section of GIMPs or from www.GPU72.com. Add these to a new file called worktodo.txt which should be added to the top directory.

9. Now start running mfaktc.exe in Terminal with the command ./mfaktc.exe

That should be that.

Thanks oince again to TheJudger

TheJudger · 2017-12-22, 19:48

Quote:

Originally Posted by TheJudger

Hi,

guess this won't hurt many users for now: mfaktc + CUDA 9.0 + Volta architecture doesn't work. (CUDA 9.0 + Pascal seems to work fine, didn't test older architectures). For now it is unclear whether this is a bug within mfaktc or in CUDA.

Oliver

Quote:

Originally Posted by TheJudger

Currently I'm 99% sure it is the famous sub.cc/subc 0 bug again.
http://mersenneforum.org/showpost.ph...postcount=2549

Oliver

Yep, bug in CUDA 9.0 and 9.1 for Volta architecture....

Oliver

moebius · 2017-12-31, 05:29

M332538901 has a factor: 38814612911305349835664385407 [TF:76:77:mfaktc 0.21 barrett87_mul32_gs]
no factor for M332538901 from 2^76 to 2^77 [mfaktc 0.21 barrett87_mul32_gs]

Of course, the server did not accept the first result, but this is very strange....

ATH · 2017-12-31, 05:57

The factor is not correct:

2^332538901 - 1 = 36146327836316851267023636988 (mod 38814612911305349835664385407)

axn · 2017-12-31, 07:00

That is a valid (composite) factor of M3321928619

38814612911305349835664385407 = 797262868561 x 48684837137044687

Mod(2,38814612911305349835664385407)^3321928619 == 1

TheJudger · 2017-12-31, 12:28

Hi moebius,

is this reproduceable for your setup?
default config (mfaktc.ini) or altered settings?
did this happen on a long run (several assignments without restart of mfaktc or right after the first assignment after (re-)start)?
which GPU?

As axn already mentioned: this is a valid (composite) factor for M3321928619. Why M3321928619? Because this is part of the builtin selftest which is run on every (re-)start of mfaktc. Somehow the result from the selftest isn't cleared and shown after an assignment finished. This was reported 2(?) times before, I didn't figure out why this happens yet.

Oliver

moebius · 2017-12-31, 13:32

1) Sorry, I don't want to try because it takes to long. I eventually have to go back to mfaktc-0.19 because of the overheating problem. (Cuda driver crashes after a few minutes of mfaktc-running)

2) one assignment with several restarts of mfaktc because of overheating errors
"ERROR: cudaGetLastError() returned 30: unknown error" and "ERROR: cudaGetLastError() returned 77: an illegal memory access was encountered"
3) default config (mfaktc.ini).

4)

mfaktc v0.21 (64bit built)

Compiletime options
THREADS_PER_BLOCK 256
SIEVE_SIZE_LIMIT 32kiB
SIEVE_SIZE 193154bits
SIEVE_SPLIT 250
MORE_CLASSES enabled

Runtime options
SievePrimes 25000
SievePrimesAdjust 1
SievePrimesMin 5000
SievePrimesMax 100000
NumStreams 3
CPUStreams 3
GridSize 3
GPU Sieving enabled
GPUSievePrimes 82486
GPUSieveSize 64Mi bits
GPUSieveProcessSize 16Ki bits
Checkpoints enabled
CheckpointDelay 30s
WorkFileAddDelay 600s
Stages enabled
StopAfterFactor bitlevel
PrintMode full
V5UserID (none)
ComputerID (none)
AllowSleep no
TimeStampInResults no

CUDA version info
binary compiled for CUDA 8.0
CUDA runtime version 8.0
CUDA driver version 8.0

CUDA device info
name GeForce GTX 560 Ti
compute capability 2.1
max threads per block 1024
max shared memory per MP 49152 byte
number of multiprocessors 8
CUDA cores per MP 48
CUDA cores - total 384
clock rate (CUDA cores) 1800MHz
memory clock rate: 2004MHz
memory bus width: 256 bit

Automatic parameters
threads per grid 1048576
GPUSievePrimes (adjusted) 82486
GPUsieve minimum exponent 1055144

running a simple selftest...
Selftest statistics
number of tests 107
successfull tests 107

TheJudger · 2017-12-31, 16:37

Does the card really overheat or is it just bad (broken) hardware?

Oliver

moebius · 2017-12-31, 17:06

Yes it's because of overheating, The temperatures rise sometimes over 100°C and no i don't think the card is defect, I let run CUDALucas as well on it... also for LL double check.
At a certain temperature, the GRAKA(CUDA)-driver simply crashes. Thats all, not so dramatic...

44714303

kladner · 2017-12-31, 18:40

Out of curiosity, did the report of a factor have only one line in results.txt? I have found that a "single line factor" is always spurious and happens when pushing the overclock too hard.

2017-12-12, 12:03	#2785
bayanne "Tony Gott" Aug 2002 Yell, Shetland, UK 14C₁₆ Posts	I finally managed to get mfaktc running on my Mac, with a lot of kind assistance from TheJudger. He asked me to post the method here, in case there are any other Mac users who wished to run TF on their Mac using the GPU. I am running an iMac using Mac OSX 10.11.6 El Capitan which is running an Nvidia GeForce GTX 775M. 1. Download Xcode and install 2. Download Cuda 8.0 Toolkit (version 9.0 is only for OSX 10.12 and later) and install 3. Download mfaktc-0.21.tar.gz and unpack and place the folder on your desktop 4. You then need to modify the Makefile which is in the src subdirectory as follows Change from Code: CFLAGS = -Wall -Wextra -O2 $(CUDA_INCLUDE) -malign-double CFLAGS_EXTRA_SIEVE = -funroll-all-loops to Code: CFLAGS = -Wall -Wextra -O2 $(CUDA_INCLUDE) CFLAGS_EXTRA_SIEVE = You have to remove/comment the line which contains Code: NVCCFLAGS += --generate-code arch=compute_11,code=sm_11 because CUDA 8 completely dropped support for the first gen CUDA capable GPUs (e.g. Geforce 8000, 9000 and 200 series). You may want to add Code: NVCCFLAGS += --generate-code arch=compute_60,code=sm_60 # CC 6.x GPUs will use this code which enables code generation for the current Pascal series GPUs (e.g. Geforce 1000 series). nvcc is located in a different location than expected by the makefile, thus /usr/local/cuda/bin so you would need to define the path with the following statement: export PATH=/usr/local/cuda/bin${PATH:+:${PATH}} export DYLD_LIBRARY_PATH=/usr/local/cuda/lib${DYLD_LIBRARY_PATH:+:${DYLD_LIBRARY_PATH}} You also need to advise the makefile of the path to lcudart so the following needs to be added to the start of the Makefile # where is the CUDA Toolkit installed? CUDA_DIR = /usr/local/cuda CUDA_INCLUDE = -I$(CUDA_DIR)/include/ CUDA_LIB = -L$(CUDA_DIR)/lib/ This may already been in the makefile, in which case amend /lib64/ to /lib/ 5. Now open Terminal and cd to the src subdirectory and then type make clean make This should then produce a file mfaktc.exe in the top directory of mfaktc-0.21 6. Now run ./mfaktc.exe in Terminal which will run a short selftest. If it reports no problems, it will tell you there is nothing to do. Then run ./mfaktc.exe –st which will run a longer selftest. If this completes the selftest without a single error, then it is time to get some real work. 7. The file mfaktc.ini contains the settings, and you need to amend V5UserID and Computer ID to those that you intend to use. 8. You then need to grab some exponents to test, from either the Manual Testing section of GIMPs or from www.GPU72.com. Add these to a new file called worktodo.txt which should be added to the top directory. 9. Now start running mfaktc.exe in Terminal with the command ./mfaktc.exe That should be that. Thanks oince again to TheJudger

2017-12-31, 05:29	#2787
moebius Jul 2009 Germany 1001011111₂ Posts	contradictory output in results.txt at mfaktc-0.21 M332538901 has a factor: 38814612911305349835664385407 [TF:76:77:mfaktc 0.21 barrett87_mul32_gs] no factor for M332538901 from 2^76 to 2^77 [mfaktc 0.21 barrett87_mul32_gs] Of course, the server did not accept the first result, but this is very strange....

2017-12-31, 12:28	#2790
TheJudger "Oliver" Mar 2005 Germany 11·101 Posts	Hi moebius, is this reproduceable for your setup? default config (mfaktc.ini) or altered settings? did this happen on a long run (several assignments without restart of mfaktc or right after the first assignment after (re-)start)? which GPU? As axn already mentioned: this is a valid (composite) factor for M3321928619. Why M3321928619? Because this is part of the builtin selftest which is run on every (re-)start of mfaktc. Somehow the result from the selftest isn't cleared and shown after an assignment finished. This was reported 2(?) times before, I didn't figure out why this happens yet. Oliver

2017-12-31, 13:32	#2791
moebius Jul 2009 Germany 607 Posts	1) Sorry, I don't want to try because it takes to long. I eventually have to go back to mfaktc-0.19 because of the overheating problem. (Cuda driver crashes after a few minutes of mfaktc-running) 2) one assignment with several restarts of mfaktc because of overheating errors "ERROR: cudaGetLastError() returned 30: unknown error" and "ERROR: cudaGetLastError() returned 77: an illegal memory access was encountered" 3) default config (mfaktc.ini). 4) mfaktc v0.21 (64bit built) Compiletime options THREADS_PER_BLOCK 256 SIEVE_SIZE_LIMIT 32kiB SIEVE_SIZE 193154bits SIEVE_SPLIT 250 MORE_CLASSES enabled Runtime options SievePrimes 25000 SievePrimesAdjust 1 SievePrimesMin 5000 SievePrimesMax 100000 NumStreams 3 CPUStreams 3 GridSize 3 GPU Sieving enabled GPUSievePrimes 82486 GPUSieveSize 64Mi bits GPUSieveProcessSize 16Ki bits Checkpoints enabled CheckpointDelay 30s WorkFileAddDelay 600s Stages enabled StopAfterFactor bitlevel PrintMode full V5UserID (none) ComputerID (none) AllowSleep no TimeStampInResults no CUDA version info binary compiled for CUDA 8.0 CUDA runtime version 8.0 CUDA driver version 8.0 CUDA device info name GeForce GTX 560 Ti compute capability 2.1 max threads per block 1024 max shared memory per MP 49152 byte number of multiprocessors 8 CUDA cores per MP 48 CUDA cores - total 384 clock rate (CUDA cores) 1800MHz memory clock rate: 2004MHz memory bus width: 256 bit Automatic parameters threads per grid 1048576 GPUSievePrimes (adjusted) 82486 GPUsieve minimum exponent 1055144 running a simple selftest... Selftest statistics number of tests 107 successfull tests 107 Last fiddled with by moebius on 2017-12-31 at 13:33

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
mfakto: an OpenCL program for Mersenne prefactoring	Bdot	GPU Computing	1676	2021-06-30 21:23
The P-1 factoring CUDA program	firejuggler	GPU Computing	753	2020-12-12 18:07
gr-mfaktc: a CUDA program for generalized repunits prefactoring	MrRepunit	GPU Computing	32	2020-11-11 19:56
mfaktc 0.21 - CUDA runtime wrong	keisentraut	Software	2	2020-08-18 07:03
World's second-dumbest CUDA program	fivemack	Programming	112	2015-02-12 22:51

2017-12-12, 03:19	#2784
James Heinrich "James Heinrich" May 2004 ex-Northern Ontario 11×311 Posts	I've heard of MISFIT but never used it. Tell me what needs to be changed to the API for my site and I'll make it work.

2017-12-31, 05:57	#2788
ATH Einyen Dec 2003 Denmark 6126₈ Posts	The factor is not correct: 2^332538901 - 1 = 36146327836316851267023636988 (mod 38814612911305349835664385407)

2017-12-31, 07:00	#2789
axn Jun 2003 2·3·7·11² Posts	That is a valid (composite) factor of M3321928619 38814612911305349835664385407 = 797262868561 x 48684837137044687 Mod(2,38814612911305349835664385407)^3321928619 == 1

2017-12-31, 16:37	#2792
TheJudger "Oliver" Mar 2005 Germany 11×101 Posts	Does the card really overheat or is it just bad (broken) hardware? Oliver

2017-12-31, 17:06	#2793
moebius Jul 2009 Germany 607 Posts	Yes it's because of overheating, The temperatures rise sometimes over 100°C and no i don't think the card is defect, I let run CUDALucas as well on it... also for LL double check. At a certain temperature, the GRAKA(CUDA)-driver simply crashes. Thats all, not so dramatic... 44714303

2017-12-31, 18:40	#2794
kladner "Kieren" Jul 2011 In My Own Galaxy! 10158₁₀ Posts	Out of curiosity, did the report of a factor have only one line in results.txt? I have found that a "single line factor" is always spurious and happens when pushing the overclock too hard.