kind odd at 768mb

[ConTRo13R]

This does strike me as a bit odd, i've never really questioned it till now.

But why 768 and not a full gig?

it seems to just break away from the norm, is it a 512 with a 256 added or a full 1024 with 256 used for something else?

 

[Phatzy]

nvidia like to be different

 

[Tetras]

Memory bus + chip size, they don't plug a 768MB chip on, it is made up of smaller ones.

 

[Tute]

nVidia love to do it.

320MB and 640MB anyone?

 

[Craig321]

This does strike me as a bit odd, i've never really questioned it till now.

But why 768 and not a full gig?

it seems to just break away from the norm, is it a 512 with a 256 added or a full 1024 with 256 used for something else?

Mine's 896MB

 

[ConTRo13R]

it just seems to smash a mould

16
32
64
128
256
320
512
640
768
1024

Theres just no logic to it!

 

[helmutcheese]

it just seems to smash a mould

16
32
64
128
256
320
512
640
768
1024

Theres just no logic to it!

Its perfectly Logical.

The normal numbers like 32/64/126/256/512 are on a 256bit bus.

The abnormal numbers are on the newer buses like the higher end GTX/Ultra with a 384bit.

They always need be MULTIPLES.

256bit Bus x 2 = 512MB Memory (example 8800GT).

384bit Bus x 2 = 768MB Memory (example 8800GTX).

 

[ConTRo13R]

^^^^ooooo i get it lol^^^^

Clever stuff all those numbers

 

[helmutcheese]

 

[LoadsaMoney]

Aye Nvidias the kings when it comes to numbers.

 

[Lightnix]

Yeah, basically, memory-bus * chip capacity = total vram

So the GTX260 with its 448-bit interface would need 14 64MB (512Mbit) memory chips, presuming the usual 64-bit per two chips setup.

 

[Monkeynut]

So when ATI did a 256-bit bus with GDDR5 they halved the chips they used?

Clever.

 

[Tute]

So when ATI did a 256-bit bus with GDDR5 they halved the chips they used?

Clever.

Good thing as well, given the GDDR5 shortage the 4870 range caused.

 

[willhub]

How much ram would you need on a 666-bit bus?

 

[Cyber-Mav]

How much ram would you need on a 666-bit bus?

you not been paying attention to this thread or is you maths really that bad?

start with the figure 666mb to match the 666bit bus.
then either double or quadruple the ram density for 666x2 = 1332mb
or even use lower density for 333mb. can even use double of 1332mb if need be but the multiplication or divisional factor remains the same.

nvidia used a 192bit mem interface on some of thier cards, and those cards have 384mb, 768mb and could even have been shipped with 192mb or even 96mb ram if they use the correct number and density of chips.