Windows 7 - Help in GTX 570 sli

I have two GTX 570's with different brands
One is gigabyte with 780 MHz core clock
And the other is an asus with 742 MHz core clock
Both of them are factory over clocked
I don't intend to overclock
I read that I should put the one with slower clock speed on the pciX16 slot and the higher clock on the X8 slot
But I use the gigabyte z68x-ud7-b3
And it has 2 X16 slots
Any help please

Unless your board/chipset specifically allows dual x16 while in SLI, both of your cards will run at 8x. Since they are both listed at x16 both of these slots are equal in terms of available bandwidth.

One way to check if your board will allow x16/x16: Install both cards, and check the bios. It should tell you what speed your slots are running with both cards installed.

On a side note, running cards at x16/x16 has shown no real world performance gain(with the exception of triple monitor setups). The only place you will see any increase is specific benchmarks.

Try putting them in the x16 slots. Looking at the slots on your board, this will allow for better airflow to the cards as well. SLI and X-fire rigs can get toasty

Hope this helps!
~V

+1 for that did the same thing and they get very toasty look for a fan control program or use the nvidia forceware to tweek it

you will need extra cooling belive me some games renders shut downs if it gets to hot

Not sure that psu is big enough for sli, minumn for one is 550 so for two and everything else in the comp that takes power you will need at least 1000w psu and more cooling.

That is a good thought Bowtie, however I did some searching and found quite a few benchmarks in terms of max power draw for 570s. They all seem to top out around ~300w.

Ahmedss shouldn't have any issue running them in SLI with his current PSU.

I looked up the spec's for the 570 on NVidia and it said minumn 550W for one.

The PSU is not an issue ,I could get 850w and it would be sufficient to run both the cards
But my main concerns are the VGA cards
And I just found that my motherboard has two X16 pci slots

After Botwie mentioned cooling, I took a look at your case.(Good thinking! I did not look at the case in terms of the cooling setup.) If you are running with the stock cooling, you are definitely going to need at least two more fans for an SLI setup. One fan pushing out the back is not going to cut it for those cards.

It should not matter which card is placed in which slot, assuming you place them in the x16 slots. According to what I read, SLI will reduce the card with the faster core clock down to that of the lower clocked card. So both cards will be running a core clock of 742Mhz.
If anyone has experience when running SLI with different core clocks please chime in, as this is just what I've read!

The "mfg required" minimum wattage for cards in my experience are always far beyond what the cards will use, usually by ~150-200w. This is not just the requirement for the card, but for the whole rig with the card installed. Shouldn't need a 1000W PSU to SLI these.

V43LIN point taken, but there are other concerns to take into concideration, how many HDD's, fans, dvd-roms, etc, so my point is you have to concider all the factors when doing this.

Absolutely, please do not take my experiences or opinions as an insult to your experience or knowledge. Was just trying to give the OP additional information that should be taken as equal with your own