I am hoping that someone can help me, I have done a search and the concensus is that I can crossfire a 1Gb 4870 to a 512mb.
I currently have a 512mb 4870 and am looking to buy a cheap 2nd hand 1GB 4870. The thinking is that if I come across a game that is not good with crossfire set-ups I can disable crossfire and run the 1GB 4870 on its own.
Does anyone have a similar set-up and is disabling crossfire a simply case of unticking a box in CCC or am I being naive.
It dosent add up. 2 cards with 512mb give you 512mb net . If you use a 1gb card and a 512mb card you still only get 512mb.
I will try to explain.
In Crossfire you would by default be using AFR (Alternate Frame Rendering) it dosent make a differance if you use checkerboard or split screen rendering the result as far as the Ram on the cards goes is the same.
In order to calculate what it needs to do to render each frame both card needs (unfortunatly) to calculate the same information so you end up with two sets of identicle info on each card.
SLI or CF is not a SUM of the 2 cards RAM. Its mostly the calculating power that is "doubled".
I think your plan is not bad. With games that support CF youll have better Performance. And with games that dont youll have the 1gb. Remember that The 1gb is not really faster. read reviews about the games you play and see BENCH to know if your CF worth it or not.
Maybe it can be better for you to sell your current 4870 and buy a Single GTX285 or GTX275 ? Depand on games you play. Find benchmark !
1680 x 1050 - I generally play FPS and driving games.
I think you are right when CF is running well but am a little worried about heat and stabilty with my current set-up (Lian Li A17 case and HW620W PSU) thus inclined to go with a single card solution e.g. GTX 275 or HD4890.