Hi James,

[QUOTE=James Heinrich;363688]Hmm... sounds promising... any chance of it getting ported to mfaktc?[/QUOTE]

Port what? GPU kernels using only 15 bits per integer? No way (until Nvidia changes the hardware (which I hope never happens)). You need to understand why mfakto has this kernels:[LIST][*]AMD GPUs still [I]prefers[/I] 24 bit integer multiplication over 32 bit[*]AFAIK OpenCL doesn't provide access to hardware carry[*]I'm unsure about this: is it possible to calculate the top bits of a 24x24 multiplication with OpenCL on AMD GPUs?[/LIST]
Oliver

FWIW, you can install CUDA via a package manager now. We did the Ubuntu 12.04 version and it worked as advertised. This should (?) alleviate problems with updated drivers breaking the system.

[url]http://docs.nvidia.com/cuda/cuda-getting-started-guide-for-linux/index.html#install-cuda-software[/url]

Edit: Also, with Ubuntu 12.04 we were able to access the fan controller. The default BIOS (?) fan curve allows the card to get real close to 80°C which is (we think) where it is apt to throttle performance. We set the fan to 70% and the temperature is a stable 65°C under load. Unfortunately there is no option to have the fan speed change based on GPU temperature, like using EVGA's Precision X software in Windows, but since mfaktc runs 24×7 the environment is stable.

[url]http://askubuntu.com/questions/42494/how-can-i-change-the-nvidia-gpu-fan-speed/299648[/url] →In particular, the answer with "sudo nvidia-xconfig --cool-bits=4" in it.

Hello,

I've just discovered a bug in mfaktc 0.20. The good news is that I think this bug can never lead to false negatives (factor missed) because it just crashes mfaktc during the first call to a kernel which uses GPU sieving. The issue is that more shared memory than available is requested (depending on the values of GPUSieveProcessSize and GPUSievePrimes). I noticed this when using GPU sieving on CC 1.x GPUs which have only 16kiB of shared memory while newer GPUs (2.x and 3.x) have 48kiB which requires obscure settings of GPUSieveProcessSize and GPUSievePrimes to trigger the bug.

mfaktc 0.21 will check the settings:
[CODE][...]
GPUSievePrimes 50000
[...]
GPUSieveProcessSize 32Ki bits
[...]
CUDA device info
name GeForce GTX 275
compute capability 1.3
[...]
Using GPU kernel "75bit_mul32_gs"
ERROR: Not enough shared memory available!
Need 31457 bytes
This GPU supports up to 16384 bytes of shared memory.
You can lower GPUSieveProcessSize or increase GPUSievePrimes to lower
the amount of shared memory needed
[...]
[/CODE]

Oliver

[CODE]top - 14:14:37 up 2 days, 19:12, 5 users, load average: 4.01, 3.94, 3.80
Tasks: 188 total, 6 running, 182 sleeping, 0 stopped, 0 zombie
Cpu0 : 2.2%us, 0.5%sy, 96.6%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.5%si, 0.0%st
Cpu1 : 1.7%us, 0.2%sy, 97.7%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu2 : 1.8%us, 0.2%sy, 97.7%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu3 : 1.8%us, 0.2%sy, 97.6%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 16380940k total, 3959672k used, 12421268k free, 214876k buffers
Swap: 0k total, 0k used, 0k free, 1427968k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ P COMMAND
1145 root 20 0 211m 100m 65m S 0 0.6 51:48.99 1 /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
2631 m 20 0 1213m 61m 29m S 2 0.4 32:25.85 0 /usr/lib/squeak/4.4.7-2357/squeakvm -encoding UTF-8 -vm-display-x11 -xshm -plugins /usr/lib/scratch/plugins/:/usr/lib/squeak/4.4.7-2357/ -vm-sound-oss /usr/share/scratch/Scratch.image
[B]2325 m 20 0 [COLOR="Red"]32.1g[/COLOR] 88m 81m S 2 0.6 19:17.68 0 ./mfaktc.exe[/B][/CODE]
:confused:

[QUOTE=Xyzzy;365479][CODE]top - 14:14:37 up 2 days, 19:12, 5 users, load average: 4.01, 3.94, 3.80
Tasks: 188 total, 6 running, 182 sleeping, 0 stopped, 0 zombie
Cpu0 : 2.2%us, 0.5%sy, 96.6%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.5%si, 0.0%st
Cpu1 : 1.7%us, 0.2%sy, 97.7%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu2 : 1.8%us, 0.2%sy, 97.7%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu3 : 1.8%us, 0.2%sy, 97.6%ni, 0.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 16380940k total, 3959672k used, 12421268k free, 214876k buffers
Swap: 0k total, 0k used, 0k free, 1427968k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ P COMMAND
1145 root 20 0 211m 100m 65m S 0 0.6 51:48.99 1 /usr/bin/X :0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
2631 m 20 0 1213m 61m 29m S 2 0.4 32:25.85 0 /usr/lib/squeak/4.4.7-2357/squeakvm -encoding UTF-8 -vm-display-x11 -xshm -plugins /usr/lib/scratch/plugins/:/usr/lib/squeak/4.4.7-2357/ -vm-sound-oss /usr/share/scratch/Scratch.image
[B]2325 m 20 0 [COLOR="Red"]32.1g[/COLOR] 88m 81m S 2 0.6 19:17.68 0 ./mfaktc.exe[/B][/CODE]
:confused:[/QUOTE]

That's normal. It just means it's using 32.1 GB of virtual memory, including mapped files and shared memory with the graphics card. The actual RAM used is 88 MB in that case, of which 81 MB is shared libraries (which may also be used by other programs, and in this case is probably the CUDA libraries). The SWAP column shows the virtual memory space that's not currently using RAM.

It does the same thing on my home machine. You'll see I have 16 GB of RAM and no swap used.

[code]top - 15:37:26 up 7 days, 18:15, 3 users, load average: 4.19, 4.07, 4.06
Tasks: 214 total, 1 running, 212 sleeping, 1 stopped, 0 zombie
Cpu(s): 0.2%us, 0.0%sy, 99.3%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.5%si, 0.0%st
Mem: 16435484k total, 9251140k used, 7184344k free, 347556k buffers
Swap: 8384508k total, 0k used, 8384508k free, 7467728k cached

PID USER NI VIRT SWAP RES SHR DATA CODE S %CPU P %MEM TIME+ COMMAND
3321 m 10 930m 416m 514m 1824 880m 29m S 397 3 3.2 44381:09 ./mprime -d
3254 m 0 32.1g 32g 47m 42m 31g 604 S 0 2 0.3 16:05.84 ./mfaktc.exe -d 1
3677 m 0 32.1g 32g 43m 37m 31g 604 S 0 3 0.3 71:23.11 ./mfaktc.exe -d 0[/code]

[QUOTE]Edit: Also, with Ubuntu 12.04 we were able to access the fan controller.[/QUOTE]
We decided to add a second video card to our system. After much trial and error we discovered that we cannot control the fan on the second video card unless we have a display attached to it. So, since our monitor has multiple ports, we plugged the second video card into the monitor and set up two displays. We have attached our xorg.conf file because we had to edit that manually. We do not use the second display, and if we switch inputs, it just shows a bright blank screen, so we probably set it up wrong. But the fan control works!

:mike:

[SIZE="1"]PS - The fan settings are not persistent across reboots.[/SIZE]

Is it possible to modify the program to trial factor Gaussian Mersenne and Quotient? Any help from coders will be appreciated.:bow:

CUDA 6.0-rc reveals compute capability 3.[B]2[/B] which supports [URL="http://www.mersenneforum.org/showpost.php?p=363167&postcount=2294"]funnel shift[/URL], too. :smile:
CUDA 5.5 doesn't know 3.2 (while it knows 3.0 and 3.5).

I'm curious about Maxwell chips (currently only available on GTX 750 (Ti))...

Oliver

[QUOTE=TheJudger;367461]CUDA 6.0-rc reveals compute capability 3.[B]2[/B] which supports [URL="http://www.mersenneforum.org/showpost.php?p=363167&postcount=2294"]funnel shift[/URL], too. :smile:
CUDA 5.5 doesn't know 3.2 (while it knows 3.0 and 3.5).

I'm curious about Maxwell chips (currently only available on GTX 750 (Ti))...

Oliver[/QUOTE]

Is v0.21 still in beta?

Luigi

[QUOTE=TheJudger;367461]CUDA 6.0-rc reveals compute capability 3.[B]2[/B] which supports [URL="http://www.mersenneforum.org/showpost.php?p=363167&postcount=2294"]funnel shift[/URL], too. :smile:
CUDA 5.5 doesn't know 3.2 (while it knows 3.0 and 3.5).

I'm curious about Maxwell chips (currently only available on GTX 750 (Ti))...[/QUOTE]Any idea on the sudden jump from Compute 3.5 to 5.0 for the Titan Black?
[url]https://developer.nvidia.com/cuda-gpus[/url]

[QUOTE=James Heinrich;367472]Any idea on the sudden jump from Compute 3.5 to 5.0 for the Titan Black?
[url]https://developer.nvidia.com/cuda-gpus[/url][/QUOTE]

I *guess* it is a typo...