Aces High Bulletin Board

General Forums => Hardware and Software => Topic started by: watanna on March 16, 2010, 11:23:06 AM

Title: Are both of my video cards working?
Post by: watanna on March 16, 2010, 11:23:06 AM

    I am running twin Nvida 8800GT's.  When I do ctrl I it says 512 video memory.  Each card has 512 and what little memory I still have, I think the display used to be 1024.  Are both cards working in the game?  Be gentle in your replies.  Seniors still have fellings. :old:

Title: Re: Are both of my video cards working?
Post by: Skuzzy on March 16, 2010, 11:28:16 AM

SLI combines the cards, but it does not double the video RAM.

Title: Re: Are both of my video cards working?
Post by: Masherbrum on March 16, 2010, 11:42:41 AM

Quote from: Skuzzy on March 16, 2010, 11:28:16 AM

SLI combines the cars, but it does not double the video RAM.

What Der Skuzzinator said.   

Title: Re: Are both of my video cards working?
Post by: ebfd11 on March 16, 2010, 09:31:05 PM

Skuzzy:
  I don't mean to doubt what you say but when I went SLI on my 9800's I went from 512 to 1024. So did I do something different?
Will post screenies when I get home.


Ohh BTW if I am incorrect I will send you a bottle of your fav sippy sip.

Title: Re: Are both of my video cards working?
Post by: BaldEagl on March 16, 2010, 11:03:33 PM

Quote from: Skuzzy on March 16, 2010, 11:28:16 AM

SLI combines the cards, but it does not double the video RAM.

When I SLI'd my 8800 GTS's my available system RAM went from 3.25Gb to 2.75Gb.  When I took the second card out it was back at 3.25Gb so Windows is certainly counting it.

Title: Re: Are both of my video cards working?
Post by: Skuzzy on March 17, 2010, 06:36:39 AM

It does not matter what Windows reports.  The two cards are essentially sharing video RAM, regardless of the configuration.

If you are drawing one frame, both cards have to have the exact same information loaded into them, thus lowering the available RAM on both cards to the same level.

If you are drawing every other frame, the same applies again.

You can look at it this way, if it will make you feel better.  Yes, it is doubling the video RAM, but it takes twice as much data to render any given frame than it does with one video card.

Title: Re: Are both of my video cards working?
Post by: Masherbrum on March 17, 2010, 06:49:14 AM

Quote from: ebfd11 on March 16, 2010, 09:31:05 PM

Skuzzy:
  I don't mean to doubt what you say but when I went SLI on my 9800's I went from 512 to 1024. So did I do something different?
Will post screenies when I get home.


Ohh BTW if I am incorrect I will send you a bottle of your fav sippy sip.

Send the 1/5th to him.   

Title: Re: Are both of my video cards working?
Post by: Skuzzy on March 17, 2010, 08:14:26 AM

Oh, if you are using a 32bit OS, you will lose access to the total amount of RAM on both cards as Windows still has to memory map the video space below the 4GB address limit.  So if your computer has 4GB of RAM and each video cards has 512MB of RAM, your addressable space for the operating system is reduced to 3GB.  Useable around 2.5GB.

Title: Re: Are both of my video cards working?
Post by: watanna on March 17, 2010, 11:46:33 AM

       Thank you all for the info.  I feel so much better now that I've been Shuzzyfied.  Thanks again.  BLT