Memory Bus 384bit vs 512bit for Multi Monitor

[UaVaj]

For the same money.

Triple GTX 580 SLI w/ 3GB w/ 384bit
or
Single GTX 690 SLI w/ 4GB (2gb x 2) w/ 512bit (256bit x 2)

resolution is 3 monitor w/ 5760x1080 with "ALL" the eye candy.


GPU - no brainer. triple 580 will out calcalute 690 (dual 680) at the expense of bigger electric bill.

2.5gb vram - pretty much coverd 99% of all available title at max settings at 5760x1080. 3gb is the sweet spot.



384bit or two 256bit - i not sure on this one. hopefully someone can fill in. keep in mind the resolution and all the eye candy.

 

[brandon888]

For the same money.

Triple GTX 580 SLI w/ 3GB w/ 384bit
or
Single GTX 690 SLI w/ 4GB (2gb x 2) w/ 512bit (256bit x 2)

resolution is 3 monitor w/ 5760x1080 with "ALL" the eye candy.


GPU - no brainer. triple 580 will out calcalute 690 (dual 680) at the expense of bigger electric bill.

2.5gb vram - pretty much coverd 99% of all available title at max settings at 5760x1080. 3gb is the sweet spot.



384bit or two 256bit - i not sure on this one. hopefully someone can fill in. keep in mind the resolution and all the eye candy.

GTX 690 is with only 2 GB vram .. not 4Gb .... better go with 670 4Gb sli .... and it's not 512 also .. it's 2 cards with 256 as you said .. so it's only 256 bit summary .....


i suggest you to wait for 700 series or get 670 in sli with 4 GB if you want performance now ...

 

[toyota]

bus width is irrelevant as its the actual memory bandwidth that matters. and a gtx690 effectively only has 2gb of vram since the ram is mirrored.

 

[UaVaj]

i realize 690 is OUT. memory bus is mirror just like vram. so it still 2gb and 256bit.

for the same money. 680sli with 4gb is available. however still with the 256bit memory bandwidth limitation.



the biggest question is - what memory bus is needed for 5760x1080 with all the eye candy? is 256bit enough?

 

[UaVaj]

bus width is irrelevant as its the actual memory bandwidth that matters. and a gtx690 effectively only has 2gb of vram since the ram is mirrored.

that make perfect sense. how do one go about figuring the actual memory bandwidth. what is the formula?

 

[brandon888]

that make perfect sense. how do one go about figuring the actual memory bandwidth. what is the formula?

um .... both 580 and 680 have same memory bandwidth .... cause one has 384 bit and lower memory clock ... another has 256 bit but faster memory clock ...


formula is like .... memory bus X memory clock = memory bandwidth .... so it depends not only on memory bus ... but also on memory clock ....


580 and 680 both have like 192 GT/s memory bandwidth ... what is not enough if you want to use AA in games with 3 monitors ... you have to go with amd 7970 crossfire for example or wait for 700 series if you are Nvidia fan like me 🙂

 

[Joseph F]

um .... both 580 and 680 have same memory bandwidth .... cause one has 384 bit and lower memory clock ... another has 256 bit but faster memory clock ...


formula is like .... memory bus X memory clock = memory bandwidth .... so it depends not only on memory bus ... but also on memory clock ....


580 and 680 both have like 192 GT/s memory bandwidth ... what is not enough if you want to use AA in games with 3 monitors ... you have to go with amd 7970 crossfire for example or wait for 700 series if you are Nvidia fan like me 🙂

You got that bandwidth formula mostly right, except it's specifically bus width multiplied by effective memory clock (in megahertz) with the product of that divided by eight to convert the product to bytes from bits. The final figure is in megabytes per second.

 

[brandon888]

You got that bandwidth formula mostly right, except it's specifically bus width multiplied by effective memory clock (in megahertz) with the product of that divided by eight to convert the product to bytes from bits. The final figure is in megabytes per second.

Yeah 😀 i just explained more simple ... to show that it depends not only on bus but also on memory clock ^_^


if you look at 690 benchmarks ... it's fine with 3 monitors on max settings without AA ... but with AA ... well ... you will get memory bandwidth bottleneck and maybe ram bottleneck also .... 2 GB is not too much even for 1080P single monitor .... you need at least 3 GB for 3 monitors ...

 

[SPBHM]

6000MHz * 256bits / 8 = 192GB/s
4000MHz * 384bits / 8 = 192GB/s


but on the rest the GTX 680 SLI or 690 is faster (for gaming), so it's a better card for single or multiple monitors, never compare cards from different generations just by memory bus, or even memory bandwidth... there are many other differences and improved efficiency in general... it's better to just look for some performance tests...

 

[OVerLoRDI]

If you are worried about memory bandwidth go with dual 7970s.

 

[Durvelle27]

Just get two HD 7970s as there great with really high res

 

[UaVaj]

I just found out that nvidia sucks for more than two monitor setup (three in my case which clearly affects me). with sli enabled. you only have two options (and it is missing the option i want).

option 1 = extended mode - one monitor for gaming and one monitor for desktop. last monitor 3/4/5/6 is not used (wtf nvidia). this is regardless of tri-sli or quad-sli. same rules applies (seriously wtf nvidia).

option 2 = surround mode =-all three monitor used as one. requirement is. all monitor must be same resolution, same refresh rate. (this does not apply to me as all my monitor are the same).


as for ATI. you can have whever option you want, however many monitor you want, whatever resolution you want, mix and match.

if the game supports surround, i will use all three montor. if the game does not support surround or i only want to use one monitor for the game becuase i have other stuff going on. i want the option to be able to use the other two monitor for desktop.

stupid nvidia.



if my info is wrong. please feel free to corrrect me.
anyone want to buy a gtx 580?

 

[3DVagabond]

I just found out that nvidia sucks for more than two monitor setup (three in my case which clearly affects me). with sli enabled. you only have two options (and it is missing the option i want).

option 1 = extended mode - one monitor for gaming and one monitor for desktop. last monitor 3/4/5/6 is not used (wtf nvidia). this is regardless of tri-sli or quad-sli. same rules applies (seriously wtf nvidia).

option 2 = surround mode =-all three monitor used as one. requirement is. all monitor must be same resolution, same refresh rate. (this does not apply to me as all my monitor are the same).


as for ATI. you can have whever option you want, however many monitor you want, whatever resolution you want, mix and match.

if the game supports surround, i will use all three montor. if the game does not support surround or i only want to use one monitor for the game becuase i have other stuff going on. i want the option to be able to use the other two monitor for desktop.

stupid nvidia.



if my info is wrong. please feel free to corrrect me.
anyone want to buy a gtx 580?

You would need 2x 580's for surround, unless it's the Galaxy model that did surround on one GPU. If it is the Galaxy then the surround support, or lack of it, is actually Galaxy's responsibility, not nVidia's.