Powercolor Radeon HD 3870 X2 seriously a headache

[ShyguyXPC]

Can't remember, but does the 3870x2 require a Crossfire Mobo to use the 2nd GPU, I know the newer 4870x2 doesn't, but can't remember if it was the same for the 3870x2?

have you tried connecting the display to all the monitor ports to see if one is the main one or something like that?

[nach0 party]

Actually yes, I tried plugging my montor into each port as the computer was starting up (and I kept it in there for a while each time). In the case of crossfire, I know that my motherboard is SLI compatible and my PSU is "SLI ready" or some shinanigans like that however is there a difference between SLI and crossfire?

More depressing news- I uninstalled my old video driver, I put in the new card, with the updated BIOS still the same results. However, I feel somewhat stupid for not mentioning this earlier, but the fans on the video card tend to speed up then stop suddenly for no reason even past the computers boot. I mean, I can't see anything but I know how long it takes for the thing to boot, I even put in my password on windows without being able to see anything and the card still had the same results. If I could sum up the noise it would be:
When the computer starts up, the video card gets to humming, but suddenly, the fans decrease their speed drastically, stutter, then start up. It then goes normal speed for roughly another 30 seconds and repeats. I usually like adding new things to my computer, I find it fun but this is a 300 dollar nightmare lol.

[ShyguyXPC]

actually yes, SLI & Crossfire are for all intents & purposes the same type of technology, but you can't run 2 nvidia Cards in SLI in a Crossfire Motherboard & vice versa.

Geforce 7950GX2, & 9800GX2 cards require an SLI compatible Motherboard.

a while back, a year or two or so ago, at the end of the Radeon X1950 series' life & beginning of the HD2900 series, ATI... well not ATI, but one of the Manufacturers of ATI cards, Sapphire I believe, came out with a Dual X1900/1950 based Card, that required an ATI Crossfire board to use both GPU's, otherwise it worked like a single GPU card... wasn't officially supported by ATI either, so I'm not sure if drivers ever came out from Sapphire to support Quad Crossfire for it or not.

however, I'm not sure if ATI fixed that with the 3870x2, whether it requires a Crossfire compatible motherboard to use both GPU's or not? I know the 4870x2, doesn't require it, but does if your going to use 2 of those cards... so you could run a single 4870x2 on a non-Crossfire system.

but can't seem to find any info on the 3870x2 in regards to the same thing or not?

in any case, you should still be able to get some sort of display, whether one or both GPU's are being used...

could it be the monitor cable is the culprit, do you have another system to check the monitor with to make sure its working?


as to the fans, if their set to automatically speed up & slow down (throttle) based on the GPU temps, that could be the cause of that speeding up slowing down bit, but if their physically stuttering, as in stopping & going, something is wrong there.

[nach0 party]

Ok, well heres the deal. My original intent was to not SLI or crossfire anything, therefore I purchased the HD 3870x2 because I heard it was just two 3870 gpu's glued together and worked like a happy family should. So, if I'm reading what you typed correctly, the HD2900 serious required a crossfire board to use both gpu's on a single card? So in that case, you're wondering if the 3870x2 uses the same process, and in that case I know for a fact I have an SLI compatible mobo (not crossfire) hmm. So, it's possible that getting a new motherboard may be the trick? Also, my current card (ironically) IS a x1950 pro (by sapphire) one of the best cards I've had, worked like a charm and plays games better than I thought it would. However, this card is also a crossfire supported card, it came with the crossfire bridge and I even still have the box. BUT like you said, the 2900 series began requiring a crossfire motherboard. So although my previous video card, mr x1950 worked, its apparent that maybe the 3870x2's are still primitive to the new 4870's in the manner that they require the crossfire mobo.

After all that pondering, I really hope not...... but I suppose snooping around the internet never hurt.

The monitor works fine, I put back in my x1950 every time the 3870x2 doesn't work (so my back hurts pretty badly now cause I get to put it on the floor in a corner. So therefore, the monitor works every time I plug it into the x1950, and ceases to display with the 3870. Also, I suppose the 2900's didnt support non crossfire mobo's, hopefully is not the case with the 3870's, but I suppose I'll look into that it seems very important.

My case is an antec 900, its got plenty of fans as well, I can't imagine first of all that the card is overheating that quickly to even display anything, or that it's even overheating in the first place. Even though my pc is in a corner, I clean off the dust from the fans and the thing has never had any problems with airflow.

[ShyguyXPC]

Its late, 3AM, have to get some sleep, work all day tomorrow... so Karma, EXreaction, Nemo, Pullmyfoot, etc etc, one of you guys want to chime in on this one...

maybe you guys know if the 3870x2 requires a Crossfire board or not...

as well as clarify/explain my last post what I was saying... about the early Dual GPU based X1900/1950 card etc... I don't think he understood what I was saying, since somehow he got out of my last post something about running 2 HD2900's on a single card... which is not what I said...

techPowerUp :: Sapphire X1950 Pro Dual Review :: Page 1 / 15 This is the card I'm referring to...

about ready to collapse here, so tired, don't have time to type it all out...

[KarmaKiller]

It's early here, getting ready to go to work for most of the day.

Anywho, I just remembered something.
Before I got my new GPU, I was considering a 3870x2,and I guy I talk to had one up for sale. When I was questioning him about if it would work on my Mobo (sli board) he told me it would, and he's ran it on a 780i board.
So I would say you don't need a CF compatible board.

I'll do some more research when I get home.

[nach0 party]

Hey thanks for all the help, I was up all night as well trying to find some solutions with no help, I'll be checking up on this forum probobaly every hour and keep doing some research of my own once again, I really appreciate the help

[RamonGTP]

Radeon X2 cards do NOT require a Crossfire board, likewise, nVidia GX2 cards to NOT require a SLI board.

[nach0 party]

If that's true however, then I wonder what the problem is in this case.

[KarmaKiller]

So you did the BIOS update, and it still didn't work?
You've gone through a couple of cards, so that's not it.
Another PCI-E functions ok in your tower, so I would say it's not the mobo.
Really, the only thing you haven't double checked is the Power Supply.
IMO, that's really the only other thing it could be..