help with 4850s crossfired

Well sounds like yout 700 watt must be a generic piece of crap without enough amps for 2 cards. Watts dont mean jack its all about the amps and how clean the power is.

Someone whos a better PSU guru will chime in, and recommend what you need, I never done crossfire or SLI, so I wont chime in on specifics, I just know a generic with low amps doesn't mean jack.

If your in a hurry buy one off of ATIs certified xfire list on their website. It'll most likely run a $100+ unless there is a good deal or MIR goin on.

either of Shadowthors suggestions are good, and also look at PC Power and Cooling's 750Watt in addition to those

what is an acceptable amp rating for these cards? it does not say anything about a requirement on the ati web page... i will post the info when my buddy calls me with it.

too bad you missed the MIR that ended friday. There was a Thermaltake 750W modular for $99 after instant and mail in rebates. I think that could have run 2 4850's no prob, since it had 19 amp rating across each of three rails.

What brand and model is it? Just because it is showing that it has plenty of power, that does not mean it is providing a good/clean steady supply of power. This is what the cheaper or inexpensive PSU's do, they may look good on the outside, and the specs may look good, but on the inside they just don't have what it takes.

yeah, that psu should have more than enough power for 2 4850s.

My buddy has that PSU with 2 4850s, Q6600 @ 3.6Ghz, 4GB ddr2-1066, and like six hard drives + watercooling and it powers everything fine.

Retracted

Try with 1 card at a time and see if one is bad.

NVM

Try giving the ram a little more voltage.

have not got to the point where i can over clock.... keeps crashing... everything is at stock settings.



ill try give the ram a bit more juice

went with the faster ram so he could update the cpu if needed... but would the ram speed cause this to happen? i have tryed using each card on it own. no i have not tryed one stick of ram because it runs fine with one card.

so i upped the voltage and put the cards back in... seemed to work for a little bit but crashed again after logging in a game for about 3 minutes

If the voltage doesnt fix it ima say the PSU is a good one to use but is somewhat faulty.

http://game.amd.com/us-en/crossfir [...] 0HD%204850 Scroll down to the listing for the HD 4850,
the number of cards column shows which units will support 2 or more cards in Crossfire, you will notice that the OCZ 700W unit is not on the list. Quality of the PS is important as well as the capacity, you will notice that there are 550w units on the list, but they are specific models from particular manufacturers. This list is not complete due to ongoing certification.

Noticed a number of posts WRT that mobo requiring a bios update to run stable, check to see what bios it currently has and update it if required.

After reading this thread yesterday I then poked around the web looking for info about PS requirments. I found several sites that seemed to conflict on their numbers. Here is a link from Anandtech, I tend to trust their work more than others.

http://anandtech.com/video/showdoc [...] =3372&p=10

With just one VC onboard can you get to the bios? Is everything pertainting to display correctly setup? Also with just one card can you tweak the system with the suggestions already given by the other posters, ie more/ spec mem voltage? Did you ever get to windows and try to enable CF? I see that the latest bios is a F9f.

http://www.gigabyte.com.tw/Support [...] uctID=2842

As a suggestion and because there are so many things that might could be the prob try to setup the system with just one card get it running fully and correctly and then to the second card install. One more link - http://www.anandtech.com/video/sho [...] i=3256&p=2

Especially heed the part about enabling CF and removing a second card.

Which video driver are you using?