Let me start with I am new at all of this. This is weekend homework, to install 3 Live Linux in my virtual box. I installed Ubuntu with teacher w/o problems. I am attempting Linux Mint and I keep getting

'Running in software rendering mode'
Cinnamon is currently running without video hardware acceleration and, as a result, you may observe much higher than normal CPU usage.
There could be a problem with your drivers or some other issue. For the best experience, it is recommended that you only use this mode for troubleshooting purposes.

I have trolled this forum and haven't seen the answer, I have watched and followed along on 2 YouTube videos and I'm at a loss. Any help would be appreciated.

What version of Mint? I suspect you're using an old version.

I recently installed 17.1 in a VirtualBox VM, and it automatically detected and installed the Guest Additions package. Debian did the same.

Install the VirtualBox guest additions.

With the VM running.

Now you should see CD in your file manager. Make sure it's mounted. Now in a terminal window, cd to the mountpoint, and run the installer. The installer you're looking for has the extension .run. The file name will differ depending on your architecture, IIRC.

that will be normal for any operating system running in a "fake" "virtual" simulated environment
vm's are NOT real hardware
just simulated software ONLY

gmome3 and cinnamon do need a real HARDWARE 3d card

You may have more luck with the MATE desktop -- it is less demanding of hardware.

Those DEs give me no such warning on a VirtualBox VM with the Guest Additions installed. Now, that doesn't mean it will work for all, and I'm not saying I have true hardware acceleration, but it does work along with the associated features of Cinnamon.

To the OP:

Under Settings -> Display, ensure "Enable 3D Acceleration" is enabled.
Make sure your virtual video memory is set something other than the default of 12MB.
Install the Guest Additions, if not already installed. Reboot the VM if necessary.

Hi folks,

I see the solution to "running in software rendering mode" above here and will add some comment and clarification. With the VM shut down, go to Settings > Display and check the box for "Enable 3D acceleration". If you hover over the check box, you will see a tip that "the virtual machine will be give access to the 3D capabilities available on the host." There is also an "Enable 2D Acceleration" but if I click that box instead the status bar says, "Invalid settings detected."

I am running a Mac host. The host machine you are on might make a difference.

Before I found this solution, I found discussion threads suggesting downgrading particular packages and other work-arounds. I like simple solutions and try them first. This one worked.

Paul

P.S. I also found that my new VM could not connect to the Internet. I found that, in the VM itself under Preferences > IPv4, I could change DNS from Automatic to use a DNS server like Google (8.8.8.8) for successful connection. The OpenDNS servers would also work. So, those two changes and I was ready to go.