CUDA Toolkit install using GeForce GTX 260

Hello,
I am trying to install NVIDIA DIGITS on my old desktop PC running a GeForce GTX 260 graphics card. In order for me to run DIGITS, I need CUDA Toolkit. I have been having many issues when trying to install toolkit though. Because my GPU is so old, I attempted installing CUDA 6.5 as my NVIDIA driver version is 340.104. I tried the .deb file, but got stuck in a login loop. so I rebooted and tried to install the .run file, but I get an error like this:

“The driver installation is unable to locate the kernel source. Please make sure that the kernel source packages are installed and set up correctly”
I used [uname -r] and that spits out “4.4.8-101-generic”

I also tried installing the .run file without installing the drivers in the CUDA package and get an error like this:

“Installation failed. Using unsupported compiler.”
I used [gcc --version] and it spits out 4.8.4.

I am not sure what is wrong. Am I able to use digits with such an old version of CUDA toolkit? Please help me install CUDA on my desktop.

Thanks,
Daylan

I do not know for sure, but I think it is unlikely that you will be able to use DIGITS with a GTX 260. DIGITS presumably relies on CUDNN for the low-level work, and the CUDNN hardware requirements state:

The GTX 260 is based on the Tesla architecture, which pre-dates the Kepler architecture which is the oldest supported by CUDNN. It is really not advisable to try to get a system to run with nine year old hardware and four year old software, unless you are into retro computing.