I have an Acer AT780 with onboard Intel graphics HD 630.
Where can I find the amount of memory is "dedicated" to the graphics?
How do I adjust the amount of memory being used by the 630?
I understand that you are looking for the dedicated memory for the graphics controller.
This option is found in the BIOS of your system, it comes in different values, 128MB, 256MB, 512MB. This all depends on the motherboard manufacturer, in this case it would be Acer*. You can always contact them directly so they can show you and explain how to change this option if possible.
As a reference, here is an article with frequently asked questions about Intel ® Graphics:
https://www.intel.com/content/www/us/en/support/articles/000020962/graphics-drivers.html Intel ® Graphics Memory FAQ
I hope this helps.
I am following up with your case and see that we have not heard back from you.
Were you able to change these settings in the BIOS?
If you need more assistance do not hesitate to reply.