How Does Integrated Graphics Card work

Question

many laptops are these days sold with onboard graphics card, such as the new Intel HD 4600. I am reading that the graphic processor is manufactured on the same die as the central processor.

Is the graphic processor a separate processor, or is it actually inside the CPU ? And what about the RAM, does it have its own RAM, or does it use system RAM. If so, does it have pre-assigned size of ram, or does it get whatever it needs?

Will an onboard graphics card consume less power in my laptop, than a regular card, such as ATI Radeon ? (i.e. will my battery last longer?)

Solution

The Wikipedia article linked in Indrek's comment should be a good place to start for your questions.

The integrated graphics processor is located inside the CPU. Here is a picture showing the layout of a CPU die, and the location of the graphics hardware.

The regular system RAM is shared with the GPU. It will use as much as it needs up to a maximum amount. The specifics depend on which graphics processor it is and the motherboard.

These integrated graphics are fairly energy efficient. Dedicated graphics like ATI or NVIDIA will use more power, but also generally have better performance.

There is also new technology like NVIDIA Optimus where the system can use lower power integrated graphics to save power, and switch to higher power dedicated graphics when more performance is needed.

Comments

[Indrek]

Did you check Wikipedia? en.wikipedia.org/wiki/… should answer most, if not all of your questions.

[user55325]

Note that the new Haswell CPUs also have the "Crystalwell" eDRAM chip on the same package (although not on the same die). This is 128MB of very fast memory shared between the CPU and GPU (I don't know all the details). Intel calls it "L4" cache.