What Makes A GPU Different From A CPU?

Better graphics requires a better graphics card. This much is intuitive to most people. But asking what makes a GPU different from a standard CPU is almost a trick question, because at their most fundamental level they're the same damn thing. Both pieces of hardware perform the same kind of task: they get a problem -- in the form of 0s and 1s -- and solve it at incredible speeds. The real difference between a CPU and GPU is in the architecture, as described by the number of cores each has, each of which allows a new maths problem to be solved simultaneously. Simply put, GPUs have far more cores than CPUs. The top of the line Mac Pro, for instance, has a six-core processor while the NVidia GTX 980 graphics card has over 2000.

But more cores isn't always better. To simplify quite a bit, think of a GPU as a factory and a CPU as Steven Hawking. Factory workers, each represented by a core, can complete lots of easy, similar tasks with incredible efficiency -- tasks like geometry and shading. On the other hand Mr Hawking, while incredibly smart and only occasionally baffled, is just one man. His skill set is better used on singular, complex problems like artificial intelligence.

While working in similar ways, any truly demanding game is going to require both a smart CPU and a powerful GPU. Suddenly not being about to run Dark Souls on a five-year-old Macbook is not all that surprising.


    I came here to learn something, and left dumber than when I arrived. Useless.

    holy crap that video is terrible at explaining to laymen what the difference is, it introduces more buzzwords and confuses the whole issue, sheesh !

    It's not even correct, it spends so much time deciding to convey GPU's as "geometry" processors, and yet that's hardly any of what makes "graphics", that's mostly "texturing, lighting, occlusion, etc and yet it wants to talk about "geometry" the whole time.

    All it had to do is say "graphics" is a combination of specific maths involving very parallelizable arithmetic, like painting by numbers, that can run on many simple cores. Where's the CPU's specialize in running any maths at all, hence "general", and are the difference between jack-of-all-trades, and master-of-one.

    A GPU is a dedicated processor for graphics, just like we have dedicated processors on the motherboard for networking, sound, etc. They're fast at specific tasks, but much less flexible than CPU's.

    Hence GPU's are dedicated processors for graphics, but in recent decades have been evolving to be much more "general" in their nature, faster in fact than CPU's have evolved. Which is why we call them GPGPU (General-Purpose computing on Graphics Processing Units)

    Tim Sweeny, founder and CEO of Epic Games said it best when he described how CPU's and GPU's will evolve to erode their differences away, and will have to do some " soul searching". He already knew what was going to be happening, way back in 2007.


    My understanding is:
    GPUs are closer to the RISCs (of old) = fewer functions but fast = better for repetitive graphic tasks
    CPUs are CISCs = multiple functions = unnecessary and expensive for graphics when only a few functions are needed

    Might explain why Bitcoin mining or crypto work is often done on GPU arrays.

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