How does this CPU have 400 cores?

Question

How is it that this graphics card CPU or GPU has 400 cores yet most of todays PC's have about 4 cores average or maybe even 8 cores. (Check the link below then please read on)

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=120756672885&ssPageName=STRK:MEWNX:IT#ht_4389wt_1063

I was looking at the above item and just wondered if that has 400 cores, why can't regular PC's have 400 core processors? I would think a 400 core GPU would be very expensive, yet the item is pretty cheap. Also what is a 400 core GPU like and why would we need one? I mean it sounds pretty much amazing to me.

Can anyone please answer all of my above questions the best you can, please? Thanks in advance for your help everyone! Cheers, Paul.

Answer 1

Ok, simply put, a GPU has way more to do at once time than a CPU. We do not need a 400 core CPU because that many cores is overkill for the handful of tasks that a CPU performs at any one time. A GPU on the other hand requires several hundred cores because it needs a constant stream of large scale processing to give you real time graphical output on your monitor. Your computer monitor has a lot of pixels. Each of those pixels is constantly changing color, shade, etc. A GPU needs to keep up with all of these changes all at once so that you can see what you are doing.



A GPU contains more ALUs (arithmetic logic units) which help computer these ever changing conditions on a large scale. Where a CPU may only have 4 ALUs per core, a GPU will have a far larger amount.



400 seems like a large number but these cores are small and do relatively simple task each. All of these tasks combined make up a complex system that surpasses your standard CPU when it comes to graphics. The typical graphics card has several hundred cores, it is just the standard now-a-days.

Answer 2

actually it's a GPU not a CPU... The reason why is the CPU and GPU architectures are much different. Also, those are stream processors, and the architecture is different from regular CPU's. Also, for most programs, a fast couple of CPU cores is going to be better than 400 several hundred megahertz cores. The main reason why that is, is that programs are not that far multi-threaded, and process only hundreds of calculations per second (I think), while a monitor can have resolutions of 1600x900, 1920x1080, even 2560x1600 pixels, or 1440000, 2073600, or even 4096000 pixels that each need calculation in realtime. That's why integrated and CPU graphics aren't very good.

Answer 3

Since video cards do the hard 3d rendering they need more cores. But there cores are not as good as the CPU cores. Put it this way 400 people who are not as good at math vs 6 who are good at math will get more work done fast. And video cards are supposed to play games fast

Answer 4

GPU Cores are more limited in number of functions than a CPU Core.

They do the mathematical calculations of the triangles and polygons and color intensities of the graphic creation. Pictures and movies are much simpler as they are already created and just reproduced.



A Fermi chip has about 3 billion transistors and up to 512 Cuda Cores. 6 million per core.



A Core i7 has about 731,000,000 transistors for 4 Cores. 182 million per core.





A CPU core having more transistors to create a myriad of registers and memory caches can do far more functions than a GPU core.



GPU computing



http://www.nvidia.com/object/GPU_Computing.html

http://www.nvidia.com/object/fermi_architecture.html

http://www.amd.com/US/PRODUCTS/TECHNOLOGIES/STREAM-TECHNOLOGY/Pages/stream-technology.aspx