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Questions about multi gpu setup

Posted: Wed Jan 04, 2017 1:52 am
by CeeVee
Hi,
I only started folding about a couple of weeks ago and I have a question about upgrading to multiple GPU's on my machine.
My current setup is:

Code: Select all

03:24:38:    Version: 7.4.4
03:24:38:       Date: Mar 4 2014
03:24:38:       Time: 12:02:38
03:24:38:    SVN Rev: 4130
03:24:38:     Branch: fah/trunk/client
03:24:38:   Compiler: GNU 4.4.7
03:24:38:    Options: -std=gnu++98 -O3 -funroll-loops -mfpmath=sse -ffast-math
03:24:38:             -fno-unsafe-math-optimizations -msse2
03:24:38:   Platform: linux2 3.2.0-1-amd64
03:24:38:       Bits: 64
03:24:38:       Mode: Release
03:24:38:******************************* System ********************************
03:24:38:        CPU: AMD FX(tm)-8350 Eight-Core Processor
03:24:38:     CPU ID: AuthenticAMD Family 21 Model 2 Stepping 0
03:24:38:       CPUs: 8
03:24:38:     Memory: 15.63GiB
03:24:38:Free Memory: 13.37GiB
03:24:38:    Threads: POSIX_THREADS
03:24:38: OS Version: 4.4
03:24:38:Has Battery: false
03:24:38: On Battery: false
03:24:38: UTC Offset: 0
03:24:38:        PID: 10264
03:24:38:        CWD: /var/lib/fahclient
03:24:38:         OS: Linux 4.4.0-21-generic x86_64
03:24:38:    OS Arch: AMD64
03:24:38:       GPUs: 1
03:24:38:      GPU 0: NVIDIA:2 GF119 [GeForce GT 610]
03:24:38:       CUDA: 2.1
03:24:38:CUDA Driver: 8000
I've currently got 6 cores of the CPU and the GT610 folding.
The performance of the GPU is only adding about 25% to my PPD and even when the slider is at 'medium' the screen response is very jerky and slow, so I'm planning to add some GTX1060's which hopefully will be more responsive to screen input/output.

I was wondering if it's possible to set the loading, Light/Medium/Full, per GPU slot. This would allow me to set the GPU connected to my screen to Light/Medium whilst having any other GPU's set to Full

My motherboard manual (Asus Sabretooth 990FX) states that if all four slots are filled then they'l run at 16/8/8/4.
I've read various forum posts giving conflicting opinions concerning the slot requirements for folding and the impact on GPU performance. What sort of performance differential am I likely to get between the 16 lane slot and the 4 lane slot?

Also do I need a CPU core per folding GPU ?
I've read some posts that suggest 1 CPU core per GPU whilst others seem to imply 1 core for all GPU's, which is correct?

Mod edit: added Code tags to log file section

Re: Questions about multi gpu setup

Posted: Wed Jan 04, 2017 2:42 am
by bruce
Each GPU in your system will reduce the number of CPUs allocated to a CPU slot by 1 CPU. e.g.: 8-1=7 which doesn't work so you have it set to 6. 8-2=6 which is fine.

While the GT610 is capable of earning some points folding, it's pretty slow and it can't manage both FAH and your screen updates concurrently with any degree of efficiency (as you've discovered).

Assuming that you do want both screen updates and FAH from your GT610, the most effective setting is "idle" = "true" which will pause FAH whenever you awaken Windows (when a screensaver (if you had one) would be turned off. Folding will resume when the computer considers itself idle (when your phantom screensaver would be activated).

If you add another (more powerful?) GPU, you can manage them separately using the capabilities of FAHControl. The slider doesn't include enough options. All options can be applied either globally or to each slot individually.

Assuming you put a GTX1060 in the 16x slot and assuming you plan to keep folding with the GT610, I would put it in an 8x or 4x slot where the impact will be minimal.

Depending on where you connect your monitor, the 610 can pause on idle and the 1060 --or-- the 1060 is probably fast enough to manage both your screen and FAH.

After changing your GPU hardware, you will need to reinstall the drivers from NVidia and then reinstall FAH.

Re: Questions about multi gpu setup

Posted: Thu Jan 05, 2017 11:21 pm
by MARSTG
I can confirm that the 1060 is fast enough to fold and drive the display in the same time with minimal lag. Using Win10 with the 373.06 driver.

Re: Questions about multi gpu setup

Posted: Fri Jan 06, 2017 4:14 pm
by Aurum
bruce wrote:After changing your GPU hardware, you will need to reinstall the drivers from Nvidia and then reinstall FAH.
I've never had to do that with AMD cards. Win7 detects a new device and installs the driver. You do need to reboot after Device Manager installs the new card's driver. But reinstall Nvidia drivers and FAH ???
My experience so far with my first Nvidia card shows that Nvidia driver installation is a very troublesome process.

Re: Questions about multi gpu setup

Posted: Fri Jan 06, 2017 4:33 pm
by bruce
Aurum wrote:My experience so far with my first Nvidia card shows that Nvidia driver installation is a very troublesome process.
My experience with NVidia driver installation on Linux has been troublesome. On Windows I have not had any troubles.

Re: Questions about multi gpu setup

Posted: Fri Jan 06, 2017 7:50 pm
by SteveWillis
What I do to install Nvidia drivers on Linux Mint works very well now that I've worked out all the kinks.
#for example for latest version of driver 370. It's really easy but sometimes it takes a while for the latest driver to be in the repository

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt update
sudo apt-get install nvidia-370 nvidia-settings

Then you have to go into Driver Manager. It will show 370 as installed. You then change to the generic driver (no reboot here), then back to 370, then reboot.