Evidence suggests secret nvidia on-chip cache

[Adul]

http://www.theinquirer.net/17060213.htm

What you would usually expect is that the GPU would send data into memory while running its calculations. The chip ordiniarily keeps some data in graphics memory, since the memory can remember and keep some interstates of calculations, before returning it to the GPU to get a final result.

But the result of the experiment was quite surprising; at least it surprised us a lot. Our investigator didn?t get any data transfer from chip to memory and there where no interstates. The result came straight from the chip.

 

[splice]

Hmm... I think this is where DIME (Direct Memory Execute) comes into play. AGP cards can access main memory directly for complex operations on texture maps/data through the two methods of pipelining requests and sideband addressing. So, depending on what this programmer did, the GPU may have done the manipulations directly to the data in Main Memory, effectivly never using the AGP cards video memory. This is just my guess.

 

[DaFinn]

ummmm,

"secret cache", WT? are they talking about. Nvidia clearly says they use a "quad cache" architecture on their new cards...
It's only the amount of this cache they do not reveal. Lemme search an article on this...

for exampel here

"The engineers at NVIDIA are also keenly aware of this and as a result, have incorporated their all new "Quad Cache" architecture on both the GF4 Ti and MX products. This additional on chip cache will "feed" the high speed rendering pipelines of the GeForce4 Ti and MX, with faster on die memory, versus off chip frame buffer memory, increasing overall throughput. "