How to underclock my gpu and cpu on ubuntu?

Hi!, I have to prove if my game will run right in a machine with less resources, so I think that if I underclock my GPU and my CPU(the opposite to overclock), It will be running similar to a less resources machine, so I ask you if there is a way in ubuntu, I suppose that for the processor there is an easy one, but for the GPU, I’m not sure.

PD: Another thing to “underclock” is the quantity of memory of my ram, is there a way to simulate less memory?

GPU: Nvidia GTX960
CPU: AMD FX6300.
RAM: 8GB 1866Mhz

Thanks all!

CPU and RAM frequency, maybe from the BIOS?. RAM amount I don’t know how.

For NVidia on Linux:
https://wiki.archlinux.org/index.php/NVIDIA#Enabling_overclocking

Which version of the nvidia driver you use? What brand and model is your card?

I’m using “352.21” in my GTX 960 I get the extra features in nvidia-settings with “Coolbits” “28” (as indicated in some forums):
https://devtalk.nvidia.com/default/topic/820497/-solved-coolbits-without-xorg-conf-/

But I do not know, you be careful and read what they say there on the second link about the number “28”. another link:
https://devtalk.nvidia.com/default/topic/785338/powermizer-on-the-gtx970/

With the next command the configuration is written to /etc/X11/xorg.conf using “28”:

sudo nvidia-xconfig --cool-bits=28

Restart the system.

Now in nvidia-settings you have the options for the fan on Thermal Settings and frequencies in PowerMizer. You enter the desired value in the field, and press Enter.
You verify in the fields above that the frequencies are modified when you press the Enter key. I’ve noticed that if I have Blender open, there are times that the frequencies are not changed, and I must close Blender.

You be careful, put fan in high-speed and you monitor the temperature of the GPU all the time. I know you want underclock, but anyway.

By the way, in my GTX 960 ssc is possible reduce the frequency only -200 MHz

Thanks! I will try it when I have the time and post the results here.

in GPU I would use MSI afterburner or you know, the bios, for CPU, isn’t it obvious? the bios

The problem is that MSI afterburner is only for windows, and I want to underclock only one or two minutes to prove the game in determinates scenes, and see the framerate, I don’t want to reboot the system everytime to do it.

I found this for the CPU, but I’ve never tried:
https://wiki.archlinux.org/index.php/CPU_frequency_scaling

I try the coolbits28 thing but it doesn’t seem to work. When I open blender and run the game the gpu starts to work at the maximum values. And although I enter the values it doesn’t seem to work. I will try to underclock the cpu with that soon.

I don’t think underclocking is the best method for something like this. I’d probably look into using a Virtual Machine instead and then set the hardware emulation settings as low as you need them to be. You can test how programs will interact with the computer then. Ideally, you should have a PC at the lowest spec you’re willing to support.

You can configure thins like the gpu/cpu frecuency, memory bandwidth and so on in a virtual machine? I thinked only the ram, so I will try that at first and tell you how it goes.

What minimum value is shown there under “Graphics Clock Offset” you are allowed to set?

Another way in which you could test your game in a somewhat limited graphical environment is using “nouveau” driver (Mesa/Gallium 3D) instead the nvidia driver.

The minimum value is -90Mhz, which is not enough, I will try with the VM later, although maybe if i only can downgrade de cpu with the virtual machine, the gpu will be bottlenecked enough to work underclocked as I want.

If you don’t have access to a lower spec machine, you can underclock the gpu in the bios, provided your bios allows. As for the gpu, you will most certainly need to swap a lower spec one in there. I’d recommend something a couple years old for price reasons. A GT 620 should be about right as performing well with this level of gpu will likely allow your game to run on most any modern iGPU.

You can use overdrive for the CPU if you want.

Oh and um…

Underclocking your CPU/GPU will not give you a taste of how low end users will play your game,
Remember, clock rate is pretty much a small factor.
try using a very old PC(maybe visit your mother’s house or something?)