Installing on Geekbench requires some basic knowledge of the command prompt. If you're not already familiar with the command prompt I recommend reading the first few pages of this Linux command prompt tutorial

To install Geekbench, run the following commands from the folder where you downloaded Geekbench:

tar xf Geekbench-4.3.0-Linux.tar.gz
cd Geekbench-4.3.0-Linux/
./geekbench4

If the first command returns a "file not found" error, there's a chance your browser has already uncompressed Geekbench. Substitute this command as the first command:

tar xf Geekbench-4.3.0-Linux.tar

If you're running 64-bit Ubuntu install the 32-bit compatibility libraries with the following command:

sudo apt-get install libc6:i386 libstdc++6:i386

If you're running 64-bit Debian install the 32-bit compatibility libraries with the following commands:

sudo dpkg --add-architecture i386 
sudo apt-get update
sudo apt-get install libc6:i386 libstdc++6:i386