I am pretty sure that it's the PSU. Wait until the other members post, though, because the Alienware website doesn't block me from having dual 5770's....

Possibly PSU or Possibly Heat. What temperature are your GPUs when gaming?

It is also possibly a RAM issue but I would say PSU or heat is more likely.

Hi

I have an Area 51 with crossfired ATI 5970's. These run perfectly fine in my machine. I do however have the 1100KW PSU. Are you by any chance O/Cing your CPU or Video cards at all? I actually purchased my ATI's from a retail store so these are non dell cards and when I try O/Cing the cards i get the same issue with you.. But if I leave them as stock speeds, it is very stable.

It sounds like a PSU problem or perhaps heat issue in your case.

Thanks

Hi all,   I received my Alienware rig in January and for the most part I am very pleased.  I got an Aurora with a i7-920 factory OC'd along with dual 5770's, and everything else standard for that build (6 gigs RAM, I think 350 GB HD, etc.).  Overall, this machine is great, runs very smooth, very fast.  The one problem I have come across, however, is with Crossfire.   For certain games (i.e. MW2 Multiplayer, and Torchlight) I've found that with Crossfire enabled, the system will lock up.  Essentially, I will be playing and all of a sudden the screen will simply freeze.  Ctrl-Alt-Delete will have no effect, nor will Alt-Tab.  Strangely, I will still be able to hear sound, but it will be the soundtrack/ambient music for whatever level I am on played in a loop.  Since the computer will not respond, whenever this happens I will have to hold the power button until the computer restarts.  There doesn't seem to be a lot of rhyme or reason in terms of when this happens.  Sometimes it will occur immediately after starting the game, sometimes it will occur after an hour, sometimes after 2.  In terms of regular desktop operation (internet, word processing) the system has never crashed.  For the time being, I've just disabled Crossfire and have yet to have any problems with the system since.   My question for the forum is if anyone else has run into similar issues with a setup like mine.  I know that certain games do not like Crossfire, so it may just be an ATI driver issue or a driver issue with the game, but that said, it seems odd since I haven't seen much info on various forums from people with the same problem and at this point MW2 has been out for a while and 5770's have gone through a few driver iterations.  I also am slightly nervous about my PSU, which is the 525W version, not the 875W.        So there is my story.  Any thoughts on what could be the problem?  Has anyone else in the community with similar specs also had problems like mine with crossfire.  Is there a way for me to determine what component of my system is causing the lockup, and given the nature of the lockup (frozen screen, background music still playing, no response to Ctrl+Alt+Delete) what it might be?       Thanks for any help.

Thanks for the responses folks.  In terms of whether it is a heat issue, I don't think that seems to be the problem.  The cards will get up to 84 degrees at most when I'm running either games or a bechmark like Furmark but it doesn't climb beyond there and the temps seem fairly stable.

If this is a PSU issue, my question is whether the issue is that my PSU is faulty, or whether a "good" 525W PSU can even support my system specs.  I am kicking myself because I noticed that the PSU seemed low for my specs after I ordered, but after speaking with a Dell Customer Service rep I was assured that the 525W PSU would handle my spes.  The fact that I can't find another retailer that sells a crossfire setup with anything less than a 650W PSU makes me suspicious.  It would be very frustrating for me if Dell sold me a system with a PSU that can't handle the other components they put in.  If they had just told me an 875W PSU was needed, I would have been happy to spend the extra money.

I have a system very similar to your own...

Dual 5770's in CrossFireX configuration (retail and not OC'd)
Aurora i7 920 (although I am not OC'ing it at the moment).
Standard Alienware 525 PSU
9GB DDR3
Other standard stuff

My configuration (without overclocking) is extremely stable.  I spent a fair amount of time researching which dual GPU configs I felt comfortable running with the 525W supply.  As you know, the 5770's are 40nm GPU's and have quite low power consumption specs.  These cards are working great in all XFire applications.  I am using the most recent Catalysts drivers (10.1 I think).

There are many things that can cause the lock ups you are experiencing.  I would make sure to return to normal clock speeds on the CPU/GPU and see how the system performs.  Based on my experience, I don't think the PSU is your problem.

ONE BIG NOTE:  The standard Aurora 525W PSU has two cables that have supplemental 6 pin PCIe power connectors.  On each of these cables there are two 6 pin power connectors.  ONLY ONE OF THESE CABLES IS ACTUALLY CONNECTED INSIDE THE PSU.  The other cable is dead.  So, in order to provide correct power to both graphics cards, you need to use the one cable that is energized and on that cable use both 6 pin connectors.  I had experienced a problem myself getting CrossFire to work before I figured this out.

Good Luck

@cdubs...

the antec PSU calculator is a helpful tool. Google is your friend, use it. The calculator determines how much wattage you are using at max. With the basic settings the wattage is ~320...