• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

3870 Corssfire OC Question

D

dobieg2002

Limp Gawd
Joined
May 7, 2007
Messages
234
Before I puirchase a new poser supply I wanted to run this by the [H]. I am running 2 HD3870's in crossfire and can not OC them at all. If I OC them I get a driver crash error in Vista. I don't think it is a heat issue, the card temps never go above 70c, CPU 45c and MB 50c. If I try each card separatly I can OC them to 850 / 1200 + easily. I think it is my power supply not being able to provide enough 12v to the cards. I have a cheap 600 watt V-series Ultra, that ran my SLI 7900gt's fine, but I think 3870's are just to much for it.

So do you think is the power supply, or something else?
 
I too have an OC issue - I have a 3850 and a 3870 together and Overdrive isn't functioning. I've added up my total wattage and it comes to way less than my Enermax Infiniti 650W so I can't see it's a power issue. Just out of interest what program are you using to overclock the cards seperately?
 
dobieg2002 said:
Before I puirchase a new poser supply I wanted to run this by the [H]. I am running 2 HD3870's in crossfire and can not OC them at all. If I OC them I get a driver crash error in Vista. I don't think it is a heat issue, the card temps never go above 70c, CPU 45c and MB 50c. If I try each card separatly I can OC them to 850 / 1200 + easily. I think it is my power supply not being able to provide enough 12v to the cards. I have a cheap 600 watt V-series Ultra, that ran my SLI 7900gt's fine, but I think 3870's are just to much for it.

So do you think is the power supply, or something else?
Click to expand...

if you can overclock one card but not both, it seems almost academic that you might need a better psu. remember more wattage doesn't automatically mean better. you can still buy a 600 watt psu and run your rig. corsair, seasonic, thermaltake tough power, just to name a few reputable brands.
 
Just out of interest what program are you using to overclock the cards seperately?
Click to expand...

I only had one card in the system at a time and tested individually with CCC overdrive.

if you can overclock one card but not both, it seems almost academic that you might need a better psu. remember more wattage doesn't automatically mean better. you can still buy a 600 watt psu and run your rig. corsair, seasonic, thermaltake tough power, just to name a few reputable brands.
Click to expand...

Thanks, I thought that was it, but I wanted to get a second opinion. I purchased a Therma ltake tough power 750 for 105.00 at Microcenter The 650 was 189.00. I also checked ATI's certified power supply list just to make sure.

Thanks for the input.
 
Well the powersupply didn't do much. I was able to increase the core of each card to 840 (max for the bios I am using) and I can't even touch the memory without issues. I think there may be an issue with the drivers. I have read about others having issues after updating to 8.1 drivers and even worse when they installed the 8.2s. I'm hoping it is fixed in new drivers.
 
I have mixed 3870 + 3850 crossfire 600 watt psu the way to oc
the cards use riva tuner for the main card and overdrive for the 2nd card
this is the way I do it...hope this helps
 
You must log in or register to reply here.
Back
Top