Re: General question about mobo's video cards & ram

DaMonkeyBoy wrote:
> Howdy,
>
> Just wondering if the motherboard uses ddr ram and the video card has
> ddr2 ram on board, will the video card work plugged into said board?
>
> Kleptic

Simplified system picture -

Processor
|
Graphics Video AGP slot |
Memory ---- GPU ----------------- Northbridge --- System_Memory
or PCI Express |
|
Southbridge
| |
Disks PCI_Bus

The Graphics Memory is separated from the System Memory
by two chips in the path. That means there is no
relationship between Graphics Memory and System
Memory. They are isolated from one another by
the "GPU" (graphics processing unit) and "Northbridge".

The Graphics Memory could be GDDR5 and the System Memory
could be DDR2 or DDR3, and the system would still work.

The Graphics Memory type and speed, affects the performance
of the video card, and its ability to accelerate 2D or 3D
graphics operations.

The System Memory type and speed, affects the performance
of the processor and its computations.

So the two types of memory affect two very different
subsystems in the computer.

When buying a video card, the "width" of the memory
interface on the GPU, can affect how fast the GPU
can do some things. Sometimes, there are different
versions of video cards using the same GPU. One card
may have a 64 bit wide memory array, the other card
a 128 bit wide memory array. The 128 bit one could
have twice as much memory bandwidth. So sometimes,
when buying video cards, there are "Sucker Versions"
that involve less-wide memory arrays. Those
are the cards to avoid, if you're a gamer.
And sometimes there isn't a lot of price difference,
which means the video card maker is making a
bigger profit on the "Sucket Version" card.

To see some video card memory bandwidth numbers, have
a look at this page. Both the internal capabilities of
the GPU, as well as the memory used matter.

http://www.gpureview.com/videocards.php

I've seen a variation of up to a factor of four, between
the worst and the best using the same video card GPU. Which
is why, when shopping for a video card, you want to
read all the clock numbers and widths, and compare them
to the competition. At least, if you want to get your
money's worth.

Paul

"Paul" <> wrote in message news:gm6plg$gvk$...
> DaMonkeyBoy wrote:
> > Howdy,
> >
> > Just wondering if the motherboard uses ddr ram and the video card has
> > ddr2 ram on board, will the video card work plugged into said board?
> >
> > Kleptic
>
> Simplified system picture -
>
> Processor
> |
> Graphics Video AGP slot |
> Memory ---- GPU ----------------- Northbridge --- System_Memory
> or PCI Express |
> |
> Southbridge
> | |
> Disks PCI_Bus
>
> The Graphics Memory is separated from the System Memory
> by two chips in the path. That means there is no
> relationship between Graphics Memory and System
> Memory. They are isolated from one another by
> the "GPU" (graphics processing unit) and "Northbridge".
>
> The Graphics Memory could be GDDR5 and the System Memory
> could be DDR2 or DDR3, and the system would still work.
>
> The Graphics Memory type and speed, affects the performance
> of the video card, and its ability to accelerate 2D or 3D
> graphics operations.
>
> The System Memory type and speed, affects the performance
> of the processor and its computations.
>
> So the two types of memory affect two very different
> subsystems in the computer.
>
> When buying a video card, the "width" of the memory
> interface on the GPU, can affect how fast the GPU
> can do some things. Sometimes, there are different
> versions of video cards using the same GPU. One card
> may have a 64 bit wide memory array, the other card
> a 128 bit wide memory array. The 128 bit one could
> have twice as much memory bandwidth. So sometimes,
> when buying video cards, there are "Sucker Versions"
> that involve less-wide memory arrays. Those
> are the cards to avoid, if you're a gamer.
> And sometimes there isn't a lot of price difference,
> which means the video card maker is making a
> bigger profit on the "Sucket Version" card.
>
> To see some video card memory bandwidth numbers, have
> a look at this page. Both the internal capabilities of
> the GPU, as well as the memory used matter.
>
> http://www.gpureview.com/videocards.php
>
> I've seen a variation of up to a factor of four, between
> the worst and the best using the same video card GPU. Which
> is why, when shopping for a video card, you want to
> read all the clock numbers and widths, and compare them
> to the competition. At least, if you want to get your
> money's worth.

That chart is immensely useful, I just wish they'd add noise specs to it.
The latest AMD offerings (4870 and 4850) sould like damned vacuum
cleaners when they're under load. Nvidia's 260 and 28x/29x run cooler
and have much quieter fans.
>
> Paul