# How exactly does dual graphic cards work?



## Skaarj (Aug 2, 2007)

Just a quick question..I'm looking into buying a new PC and this new PC uses two graphic cards, so I was wondering how exactly that worked. I know a graphics takes up a certain amount of computer memory based on the card. So say i have 1 512MB card and 1 256MB card, will this mean that I have 768MB of graphic memory?

And also, here are the parts for my new computer and also im wondering if it's a good price for what i'll be getting

*$1587.00*
(before all applicable rebates)


*CASE*: ($20 off Mail-in Rebate) X-Cruiser Mid-Tower 420W Case W/ WINDOW, MultiMeter Display & Control (Black Color)

*CPU*: (Sckt775)Intel® Core™ 2 Duo E6850 CPU @ 3.00GHz 1333FSB 4MB L2 Cache 64-bit

*MOTHERBOARD*: (Quad-Core FSB1333) Asus P5N-E nForce 650i SLI Chipset LGA775 FSB1333 DDR2 Mainboard

*MEMORY*: (Req.DDR2 MainBoard)2GB (2x1GB) PC6400 DDR2/800 Dual Channel Memory (Corsair Value Select or Major Brand)

*VIDEO CARD*: NEW!!! NVIDIA GeForce 8600 GTS 512MB 16X PCI Express (EVGA Powered by NVIDIA)

*VIDEO CARD 2*: NEW!!! NVIDIA GeForce 8600 GT 256MB 16X PCI Express (EVGA Powered by NVIDIA)
*
LCD Monitor*: ViewSonic Q19WB 19& quot; 5ms Response Time COLOR TFT Active Matrix WXGA LCD Display 1440x900 (Black)

*HARD DRIVE*: Single Hard Drive (320GB SATA-II 3.0Gb/s 16MB Cache 7200RPM HDD)
*
Data Hard Drive*: NONE

*Optical Drive*: (Special Price) 18X DVD±R/±RW + CD-R/RW DRIVE DUAL LAYER (BLACK COLOR)
*
Optical Drive 2*: 16X DVD ROM (BLACK COLOR)
*
SOUND*: 3D WAVE ON-BOARD 5.1 SOUND CARD

And a Diamondback Razer mouse and Windows Vista Home Basic.


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## pharoah (Aug 28, 2006)

no its means you will have only 256 usable memory.sli only doubles the gpu not the ram.if you have 2 cards of the same type with different memory ammounts.it will default to the lower one.


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## Skaarj (Aug 2, 2007)

Hmmm so would it be a waste of money to upgrade 1 graphics card to 512 and leave the other at 256? 

Maybe I'll just upgrade both to 512. :grin:

EDIT: What exactly is GPU? Lol sorry noob question :sigh:


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## 1 g0t 0wn3d (Jan 31, 2007)

grafics processesing unit


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## Skaarj (Aug 2, 2007)

Well i went in and redid how i'd like my computer lol

$1667.00
(before all applicable rebates)


*CASE*: ($20 off Mail-in Rebate) X-Cruiser Mid-Tower 420W Case W/ WINDOW, MultiMeter Display & Control (Black Color)

*CPU*: (Sckt775)Intel® Core™ 2 Duo E6550 CPU @ 2.66GHz 1333FSB 4MB L2 Cache 64-bit

*MOTHERBOARD*: (Quad-Core FSB1333) Asus P5N-E nForce 650i SLI Chipset LGA775 FSB1333 DDR2 Mainboard

*MEMORY*: (Req.DDR2 MainBoard)2GB (2x1GB) PC6400 DDR2/800 Dual Channel Memory (Corsair Value Select or Major Brand)

*VIDEO CARD*: NEW!!! NVIDIA GeForce 8600 GTS 512MB 16X PCI Express (EVGA Powered by NVIDIA)

*VIDEO CARD 2*: NEW!!! NVIDIA GeForce 8600 GTS 512MB 16X PCI Express (EVGA Powered by NVIDIA)
*
LCD Monitor*: ViewSonic Q20WB 20& quot; WSXGA Color TFT Active Matrix LCD Display 1680x1050

*HARD DRIVE*: Single Hard Drive (400GB SATA-II 3.0Gb/s 16MB Cache 7200RPM HDD)

*Data Hard Drive*: NONE

*Optical Drive*: (Special Price) 18X DVD±R/±RW + CD-R/RW DRIVE DUAL LAYER (BLACK COLOR)

*Optical Drive 2*: 16X DVD ROM (BLACK COLOR)

*SOUND*: 3D WAVE ON-BOARD 5.1 SOUND CARD


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## pharoah (Aug 28, 2006)

looks like a very nice setup,but absolutely do not use the power supply with that case.take a look at the power supply selection link in my sig.be sure to get a quality power supply to run that system.


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## HawMan (May 12, 2006)

Bin the 2x 8600 and get 1x 8800GTX.


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## 1 g0t 0wn3d (Jan 31, 2007)

Or even 1 8800 would beat the 2 8600s


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## HawMan (May 12, 2006)

My point Exactly :heartlove


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## Skaarj (Aug 2, 2007)

8800 GTS 320 MBx1 > 8600 GTS 512 x2?

EDIT:
Ok so i started reading the bit on PSU's. And i got to this part



> Therefore, if you are purchasing a power supply, one must add 30% more than the maximum power needed and displayed during your power calculator exercise, or your PSU will not be able to sustain performance during high demand times. They were simply not built nor tested to perform in that manner.


Does that mean, seeing as how my case is 420W, that I need to get a power supply that is at least 546W (30% of 420)?

If so, I have then chosen to upgrade my PSU to the Xion Supernova 600W.


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## TheMatt (May 9, 2006)

Yes, even two of the 8600GTS cards that are overclocked like the one I have will not beat a singlw 8800GTS 320MB. nVidia has a big gap between the 8600GTS and 8800GTS.

Also, for the PSU, that is a so-so quality unit. For an 8800GTS, you need at least a good 700w. Take a look at this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817341002

As for the motherboard, the P5N-E is OK, but these are better choices:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128044
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130081

I personally own the first one and am very satisfied. They are overall better quality IMO.


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## chimpinator (May 6, 2007)

Hi Skaarj,

I own the P5N-E SLI myself and I'll tell you that it is an absolutely AMAZING overclocker, I raised my e6420 from 2.1 to 3.5 GHz!

However I agree with TheMatt, I would try his gigabyte board. Looks like a good OCer, same price, SLI, and since you're putting a lot of hefty stuff in ur computer I assume you'll have lots of cooling too. Because of that, forget the P5N-E SLI which has no temperature or fan control. No idea why ASUS ripped out the fan voltage control.


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