New Trifire setup question?

[mcrustk2]

Hi.

I have a new rig with:

Asus p9X79 Deluxe MOBO
Powercolor 7990
Powercolor 7970
3X HP 24" DP Monitors

I have installed the 7990 in PCI (x16) Slot 1 and the 7970 in PCI (x16) slot 4.
I have added the crossfire bridge and booted up (no OS installed yet) but a few questions to you guys:

I want to run the rig Trifire and also Eyefinity. I want the 7970 to be the card connected to the monitors so that the 7990 can take advantage of ULPS/ZeroCore and powerdown given its the more hungry card.

A few observations:

With both cards plugged in, if I connect a monitor to the card in PCI1 its fine, if I connect a monitor ONLY to the card in PCI4 (again with both cards installed) it doesnt boot (POST beeps). its not the cards as I swapped them around and they both booted in slot 1.

With both cards plugged in, is it expected that you only plug you monitors into PCI1 (is this generally accepted as the ACTIVE/PRIMARY port)?

With Crossfire do all the monitors have to be plugged into the same SINGLE card (assume I cant put 2 on one card and 1 on another)?

Any help on this appriciated as im finding info on actual (which slots) and which connections (in xFire) a bit hit and miss..


Cheers.

 

[Rusty0611]

Yes with Eyefinity and crossfire they all have to be connected to your primary card, be that the 7970 in slot one or the 7990 in slot one. It's up to you which way round you have it but I guess you'd want the hotter of the cards to be in the coolest place for it . The coolest place depends on what type of cooler is on the 7970 really. If the 7970 is reference then the 7970 in the top slot with the 7990 below should work fine and will satisfy your demands as long as the 7990 has some kind of supplementary cooling (e.g. side fan or something)

 

[FrankJH]

The above sounds like great advice, I would also add that some mb's require you to set which PCIE slot you want "bootable"(sorry have no personal experience of this particular one)

I would also be tempted to install the 7970 in the slot you want, and completely install windows, and then install 7990 afterwards once Windows is stable.

 

[bemaniac]

You'll be crying from ULPS problems soon enough lol - disable ULPS and a great deal of relaxation is to be had. I got BSODS from card 2 after a simple driver update just because I forgot to uninstall afterburner also but that's my fault.......somehow afterburner wrote to a file telling the card to operate at 0.8V at all times including when performing 3d due to ULPS and nothing could fix it lol I had to redo windows last night. If your cards have different default clocks you can get ULPS issues too......I also have this issue. Might sell my 925mhz card and buy another 1000mhz card with the tri-cooler like my new gigabyte.

 

[Rusty0611]

Yeah to be honest ULPS causes me more issues than it solves so I have it disabled as well.

 

[mcrustk2]

Cheers guys,

Thanks for all the responses. I will swap around my GPUs and connect the monitors to the 7970.

If I disable ULPS in the reg will that stop AMDs own Zero Core technology working (which does the same thing!?)?

 

[Chrisoldinho]

Cheers guys,

Thanks for all the responses. I will swap around my GPUs and connect the monitors to the 7970.

If I disable ULPS in the reg will that stop AMDs own Zero Core technology working (which does the same thing!?)?

Yes, unfortunately so, however the 2nd card will generally run at a lower voltage (in my case anyway) when idle, even if ULPS is disabled (0.850 vs 0.950 on the top card).

However as I posted in another thread the difference I notice at the wall is approximately 25W with ULPS disabled (I have 2 7950's). To put this into context if you pay 10 pence per KwH like me then it will only cost an you an extra 10p every 40 hours, and I can guarantee at some stage you will have reliability issues with ULPS enabled, especially if you plan to do any overclocking.

HTH,
Chris.