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First Time Crossfire Setup

[L]imey

[H]ard|Gawd
Joined
Jan 9, 2009
Messages
2,046
Hi Guys,

my new PSU is arriving today, and I'll be setting up my 7970 crossfire configuration this evening.

The 2 7970's I have are the ASUS DCU2 (3 slot) and the Sapphire Boost (2 slot)

Given the layout of my Asrock extreme 3, I can put either card in the top pcie slot. The 2 slot card in the top slot leaves a 1 slot gap between the cards, whereas the Asus card in the top slot sandwiches them together more closely.

In my mind, the 2 slot card in the top slot is the way to go, my crossfire bridge seems fine to reach either way.

I attempted to boot the system yesterday with both cards in their respective slots (but only the top card powered from the PSU), and the crossfire bridge attached, but I was unable to get any video signal from the top card (sapphire) over DVI. I don't know if this is because the bottom card was only receiving power from the pcie slot, or if there is something else at work.

My plan is to re-add the Asus card tonight while I swap out the new PSU, attach the xfire bridge,, and then just fire everything up. Is there anything I'm missing or other factors to consider?

Since both cards run aftermarket cooling solutions that dump the heat into the case, should I be worried about overheating? My case is a rosewill thor with a bunch of big fans, should I plan to crank those up higher to improve the airflow over the cards?

Anything else to think about?

Thanks, I'm excited, and nervous at the same time :)
 
Your case its good, its a full tower with amazing airflow do not worry about overheating issue... But if i can recommend something its, put the 2 slots 7970 in the first slot and the 3 slots 7970 in the second slot, this will alow to more air flow circulate between both cards, being possible to keep a more cool temp, (every degree count u know.. )

About your issue, you are right all its due to the second cards are not receiving power, today cards that require extra pci-e connector not work if not aren't connected to prevent any damage on the mobo due to the high demand of power that require, i've seen some mobo fryed just for the fact that the pci-e 12v lines are just too weak for SLI/Xfire and compensate all with the power on the 4+4 power connector... Do not worry for the issue just unplugg the second card and wait until ur new PSU arrive.. Best lof lucks..
 
A follow up question:

My primary monitor is an Acer 120hz, I do all my gaming and whatnot on it.

I have a second monitor, oldschool Dell 17 inch lcd I got for free from work, I use it to put Twitch.tv or HW monitoring software up while I'm gaming on the primary.

Having both monitors attached to the graphics card was causing me a 10 degree increase in idle temps. After some research, it seems you can't correct this when you're running monitors with different resolutions/refresh rates.

So, to remedy this, I moved the dell monitor to the IGP plug on my motherboard (ASROCK extreme3) and it runs from there just fine (there is some minor screen tearing or something when I move windows across the monitors now, but it goes away once I refocus).

I know that CF disables the video outputs on the 2nd card when you go into 3d mode, so I obviously can't hook up my dell monitor to the 2nd card tonight.

Does anyone know if the IGP will continue to function with the crossfire card enabled?

I'll test it myself tonight obviously, but just curious if I should be expecting to live with the increased heat and idle clocks.
 
Yes you can use your iGPU separated from your discrete Xfire setup... You have only to have enabled on your mobo the option, and the intel HD drivers, (if you try to install the drivers with the igpu multi-monitor enabled on bios, it can maybe drop a error "can no detect the specified hardware" or something like that) let between 128 and 256mb ram to the igpu to give enough performance to handle the differents app you use on your 17"dell monitor...
 
Just some notes for things I had to do when I first went crossfire on my 6950's

At first windows installed a driver for the second card on it's on. So I opened the control center and listed under Performance, there were no crossfire options. So I went to AMD's site and downloaded the newest drivers and reinstalled them. While doing that it updated the drivers for both cards, then after a reboot I was able to enable crossfire in the catalyst control center.

Also, there has been a few times when games would just randomly start crashing on me. It's only happened probably twice in the past 2 years. Most recently after I installed Bioshock/TombRaider. But for me the issue was fixed both times by just reinstalling my drivers. Which means my drivers got corrupted somehow, could have been an issue with my raid-0 setup, but just wanted to toss that out there.
 
The iGPU will work fine, I use both outputs on my Crossfire setup. The only thing is to *NOT* enable Virtu as it cannot recognize Crossfire/SLI setups.
 
Yeah I uninstalled Virtu.

I seem to be having a window drag blur with overlapping windows now.

Any idea why that would be?
 
[L]imey;1039840959 said:
Yeah I uninstalled Virtu.

I seem to be having a window drag blur with overlapping windows now.

Any idea why that would be?

Lucid virtu affect the way the rendering process on the cards and iGPU thats how make possible the big increase on the performance of bench.. At least on 3dmark11 a test with lucidvirtu ON are considered not valid and are not possible to upload that result.. Cuz affect the rendering process on the graphic engine.. That cause LOT of problems with Xfire setups (some others do not present any issue) and SLI setup (not much).. Even me with single card it present some issues where the windows aero effect just become disabled with some app open...
 
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