256bit vs. 128

[LS1ZX10R]

This is my card. GeForce FX 5900 XT NVIDIA NV35 DX 9 300 700 256-bit 8x1

Can anyone please explain the how 256-bit improves performance over 128-bit? Is it comparable to the fsb bus width on a mobo?

 

[biostud]

Originally posted by: LS1ZX10R
This is my card. GeForce FX 5900 XT NVIDIA NV35 DX 9 300 700 256-bit 8x1

Can anyone please explain the how 256-bit improves performance over 128-bit? Is it comparable to the fsb bus width on a mobo?

no more like dualchannel (128-bit) vs single channel (64-bit)

 

[OinkBoink]

8 bits = 1 Byte

64-bit / 8 = 8

This means that it sends 8 Bytes per clock cycle or MHz.

8 X 400MHz = 3.2GB of data per second

128-bit / 8 = 16

This means that it sends 16 Bytes per clock cycle or MHz.

16 X 400MHz = 6.4GB of data per second

 

[Lonyo]

Basically it doubles the memory bandwidth.

 

[Pete]

Can anyone please explain the how 256-bit improves performance over 128-bit? Is it comparable to the fsb bus width on a mobo?
You can basically think of it as doubling your bandwidth, the same as doubling your FSB.

(The FX 5900 is 4x2, BTW, not 8x1.)

 

[Cawchy87]

Mabye this is only on my mobo (intel corp - dell 8300) but, when i upgraded from a 64 bit to a 128 bit, i had to change the value in the bios from 64 to 128. thought that was pretty wierd. anyway, anyone else have to do this?

 

[McArra]

Originally posted by: Cawchy87
Mabye this is only on my mobo (intel corp - dell 8300) but, when i upgraded from a 64 bit to a 128 bit, i had to change the value in the bios from 64 to 128. thought that was pretty wierd. anyway, anyone else have to do this?

I think you're talking about AGP aperture size, which has nothing to do with the bus capacity.

 

[Cawchy87]

Originally posted by: McArra

Originally posted by: Cawchy87
Mabye this is only on my mobo (intel corp - dell 8300) but, when i upgraded from a 64 bit to a 128 bit, i had to change the value in the bios from 64 to 128. thought that was pretty wierd. anyway, anyone else have to do this?

I think you're talking about AGP aperture size, which has nothing to do with the bus capacity.

thanks, learn something new everyday!

 

[Pete]

FYI, AGP Aperture simply tells your PC how much of your system memory to make available for your video card to use as extra space to hold textures. You typically want to set the AGP Aperture to equal your video card memory (meaning 64MB--and no more--for a 64MB video card, 128MB for a 128MB card, etc.).

Though I don't know if you mean you upgraded from a 64-bit to 128-bit memory bus video card or if you added a second stick of RAM to your Dell to go from single channel (64-bit) to dual-channel (128-bit) system memory, I don't think you'd have to change a BIOS setting either way. I don't think you'd have to even if you upgraded from a 64MB to 128MB video card.

 

[VIAN]

Usually it used to be where memory, for ex., ran at 400MHz shipping 128 bits at a time. Now they can ship 256 bits at a time. So they have effectively doubled the speed of the RAM. You could say that 400MHz 256-bit is equal to 800MHz 128-bit.

 

[OinkBoink]

i wonder when 512bit memory will be introduced...................

 

[Gagabiji]

Originally posted by: nikhilesh
8 bits = 1 Byte

64-bit / 8 = 8

This means that it sends 8 Bytes per clock cycle or MHz.

8 X 400MHz = 3.2GB of data per second

128-bit / 8 = 16

This means that it sends 16 Bytes per clock cycle or MHz.

16 X 400MHz = 6.4GB of data per second

So on a 256 bit card,

256-bit/8 = 32 bytes

Got a question here, is the 400MHz the ram speed? If it is, and if this was a X800 PRO...

32 X 900MHz = 28,800GB of data? That can't be right. I"m stupid. HELP ME!!!

 

[biostud]

Originally posted by: SirDude

Originally posted by: nikhilesh
8 bits = 1 Byte

64-bit / 8 = 8

This means that it sends 8 Bytes per clock cycle or MHz.

8 X 400MHz = 3.2GB of data per second

128-bit / 8 = 16

This means that it sends 16 Bytes per clock cycle or MHz.

16 X 400MHz = 6.4GB of data per second

So on a 256 bit card,

256-bit/8 = 32 bytes

Got a question here, is the 400MHz the ram speed? If it is, and if this was a X800 PRO...

32 X 900MHz = 28,800GB of data? That can't be right. I"m stupid. HELP ME!!!

No It's 28,8GB/s = 28,800 Mb/s

 

[Acanthus]

Originally posted by: nikhilesh
i wonder when 512bit memory will be introduced...................

Its already around, just not used in video cards or home PCs.

Edit: the problem with 512bit is the number of traces it would add to the motherboard (or graphics card), and the complexity of the memory controller.

My question would be where the hell are our 256bit dimms... screw DDR2, quadruple out bandwidth NOW the chips are out, someone just needs to design a mobo and dimms.

 

[VIAN]

32 X 900MHz = 28,800GB of data? That can't be right. I"m stupid. HELP ME!!!

It's easier when you konw what the prefixes to Byte are.

kilo = 1,000
Mega = 1,000,000
Giga = 1,000,000,000
Tera = 1,000,000,000,000

So 400MHz, the M stands for Mega, = 400 with one million zeros after it.

256/8 = 32

32 * 900MHz

OR, a better way to do it,

32 * 900,000,000 = 28,800,000,000 or 28.8GB/s

 

[BFG10K]

Computer metric is based around 1024, not 1000. Therefore all of your calculations are off.