how to set up crossfire?

[SXRguyinMA]

Alright, I scored a pair of Diamond Radeon HD 3870x2 and want to crossfire them. I know my mobo is crossfire compatible. Is it just a plug-and-play matter? Also, each card has a 6-pin and an 8-pin power connector on it. do I need to used both? I've been searching for info on how to hook these up but haven found anything solid yet

[Spawn-Inc]

if its like sli and from the pics i've seen just toss them both in with the bridge. and install the newest drivers and it should recognize both. you can confirm crossfire with gpu-z.

and you need to put any of the power plugs in regardless of crossfire yes.

[SXRguyinMA]

and you need to put any of the power plugs in regardless of crossfire yes.

but each card has 2 plugs, so I need to plug in all 4 then? thanks :up:

[Luke122]

You may also have to enable the crossfire in the BIOS. But yes, you would need to connect all 4 plugs. :)

[SXRguyinMA]

well I threw 1 card in @ lunch, had to move my pump and res, and lines, wiring, etc to fit it in, but it works. looks like hell, but works :D

I believe my weekend will be spent redoing the insides of my case :(

[SXRguyinMA]

ok I redid my rig and installed the cards, hooked up all power cables and the crossfire connector. hit the power button...it turned on for a sec, then shut off, then turned back on a couple seconds later. The top card fan was spinning, but nothing from the bottom card.

add to that the fact that I found out you NEED to have 2 drives plugged into the SATA RAID ports for it to work properly. and the size of these cards blocks my standard SATA ports...grrr.....so even if I could get them both working, it doesnt matter because I cant boot up anyways. oh well. guess I'll wait and get a new mobo thats crossfire ready (even though according to all I've read mine is) and just hook it up then

[progbuddy]

ok I redid my rig and installed the cards, hooked up all power cables and the crossfire connector. hit the power button...it turned on for a sec, then shut off, then turned back on a couple seconds later. The top card fan was spinning, but nothing from the bottom card.

add to that the fact that I found out you NEED to have 2 drives plugged into the SATA RAID ports for it to work properly. and the size of these cards blocks my standard SATA ports...grrr.....so even if I could get them both working, it doesnt matter because I cant boot up anyways. oh well. guess I'll wait and get a new mobo thats crossfire ready (even though according to all I've read mine is) and just hook it up then

Do you have at least a 700-800 watt PSU?

[SXRguyinMA]

yep, I've got the Ultra X3 800-watt (http://www.ultraproducts.com/product_reviews.php?cPath=97&pPath=632&productID=638)

[progbuddy]

yep, I've got the Ultra X3 800-watt (http://www.ultraproducts.com/product_reviews.php?cPath=97&pPath=632&productID=638)

Hmmm... It just sounds like there is a power issue if it doesn't boot up at all. Any shorts?

[SXRguyinMA]

not that I can find. like I said, it fired up for a sec, shut off, then turned itself back on. I didnt notice if both cards were working the first time it turned on, I know the second was not the second time.

whenever I get around to getting a new board or a new HDD (to run in RAID) I'll pop both cards in together again and see what happens

[p0Pe]

sounds strange that you have to have raid´ed hdd´s to get it working:S

[SXRguyinMA]

well the only reason for that is the second card will block my standard sata ports, and the only ones that will be open are the RAID ports

[p0Pe]

shouldnt you be able to use raid ports for ordinary harddrives also?

[SXRguyinMA]

I thought so...but I hooked up the sata cable to the raid port and it wouldnt boot up :?

[SXRguyinMA]

well I found for those cards you need to have x16 on both PCIe slots, only one of mine is, the other is not, but the mobo is crossfire compatible, must just not be with these cards. ah well, time to save up for a new mobo :devious:

anyone have any reccommendations for a good socket 775 board that CF ready?

[SXRguyinMA]

I'm trying to decide between this one (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3940038&CatId=2547) and this one (http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3975897&CatId=2547). anyone have any other ideas? :think:

[nevermind1534]

I usually recommend the P5Q Pro. I say get that ASUS you're looking at.

[haha49]

waste of money depends on your mb if its not dual 16x dont bother..