nVidia Cards Inside and Out - Overclock.net

se7en56 · 05-30-08

This is my first info, so bear with me

First off, video cards are overclocked using software, such as ATiTool and RivaTuner. It is possible to OC the PCI-E bus in the BIOS for a little higher of an OC, but this is harder on the hardware and more noticeable to the manufacturer. As far as I know there is no way to change voltage going to the GPU without a hard mod. A hard mod is just soldering a resistor pot between two points on a video card. I don’t know how to do that, but you can do it. This is also possible on ATI cards. Please keep in mind that increasing the voltage will increase heat and can cause electromitigation within the GPU.

I will be using my video card as an example. For the following information, I will explain what everything is:

BFG 8800 GTS

Chipset:
GPU: GeForce 8800 GTS
Core Clock: 550MHz
Stream Processors: 96
Shader Clock: 1350MHz

Memory:
Memory Clock: 1600MHz
Memory Size: 640MB
Memory Interface: 320-bit
Memory Type: GDDR3

Let’s start at the beginning, the chipset.
This card has the GeForce 8800 GTS chipset. This simply means this video card has the GeForce 8800 GTS series of the 8 series processor. To simplify it even further, it’s like an Intel QX9650 Extreme. Although I am not comparing my card to this

These chipsets vary from card to card. Although the difference could be small, there IS a difference between a GTS and a GTX and a GT. These differences include changes in some or all of the following: Core Clock, Memory Clock, Shader Clock, Memory Size, Memory Interface, Memory Type, Memory Bandwidth, etc...

Core Clock:
This is pretty straight forward. This is the speed at which your GPU processor operates. Some models come factory overclocked, and some do not. This is a major part of overclocking a video card, your real speed improvement.

Stream Processors:
These aren't vertex or pixel shaders, but generalized floating-point processors capable of operating on vertices, pixels, or any manner of data. Most GPUs operate on pixel data in vector fashion, issuing instructions to operate concurrently on the multiple color components of a pixel (such as red, green, blue and alpha), but the 8800's stream processors are scalar—each stream processor handles one component. Stream processors can also be re-tasked to handle vertex data (or other things) dynamically, according to demand. Also unlike a traditional graphics chip, whose clock frequency might be just north of 600MHz or so, these are clocked at a relatively speedy 1.35GHz, giving the GeForce 8800 a tremendous amount of raw floating-point processing power.

Shader Clock:
The Shader Clock and Stream Processors go hand-in-hand. The Shader Clock is just the clock speed of the Stream Processors. Usually the Shader Clock is directly linked with the Core Clock, but these can be unlinked for a better, more stable overclock.

Memory Clock:
Simply, the clock speed of the onboard memory, but more detailed, the memory clock, along with the size of the memory bus, tells us the amount of memory bandwidth a graphics card has. The more memory bandwidth a card has, the better it can handle higher resolutions and high levels of AA and AF.

Memory Size:
Again, pretty straight forward. This is just the size, in MB, of the memory onboard the video card. Some of the higher end cards are now starting to use 1GB for memory.

Memory Interface:
The Memory Interface is the size of the interface of the bandwidth to the memory. Higher means faster because more can be moved through in a higher interface than a smaller interface.

Memory Type:
For this video card, the Memory Type is GDDR3, which stands for Graphics Double Data Rate 3. GDDR3 is very similar to DDR2, but the power and heat dispersal requirements have been reduced somewhat, allowing for higher-speed memory modules, and simplified cooling systems. Unlike the DDR2 used on graphics cards, GDDR3 is unrelated to the JEDEC DDR3 specification. This memory uses internal terminators, enabling it to better handle certain graphics demands. To improve bandwidth, GDDR3 memory transfers 4 bits of data per pin in 2 clock cycles.

Pretty simple, huh?

P.S. I am VERY open to comments, constructive criticism, and remarks.
P.P.S. I used some information from Techreport as a cited page

airbozo · 05-30-08

Very nice thanks!
+rep

se7en56 · 05-30-08

Thank you much airbozo!!!

Shingetsu · 05-30-08

explain shader clock for teh noobies.

se7en56 · 05-30-08

That's explained in the stream processor section, perhaps I should point that out

Thanks!

Steady65 · 05-30-08

Usually the Shader Clock is directly linked with the memory Clock, but these can be unlinked for a better, more stable overclock.

This should say the shader clock is directly linked with the core clock shouldn't it?