Port 2 does not work

Blade Systems

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Sep 10, 2013
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10,510
I got a second radeon HD 7850 and when I installed it it overhung the first PCI slot. I had to move my PCI internet card to the second PCI slot and when I did it did not work. This is very confusing as the motherboard should have both of the slots working.
Motherboard: ASUS M5A97 R2.0
 

jb6684

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Gotta ask, why are you using a PCI internet card? (you have an On-board one already....) I'm assuming this is a ethernet card for connection to the internet?

Second kinda bad news, your motherboard won't do a very good job of supporting CrossFire.....

Expansion Slots
1 x PCIe 2.0 x16 (blue)
1 x PCIe 2.0 x16 (x4 mode, black) (This is PROBLEM@!@##!, your not going to get much of a performance boost from that second GPU when it's only running on an x4 mode slot... (been there, done that.....)
2 x PCIe 2.0 x1
2 x PCI
 

Blade Systems

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Sep 10, 2013
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10,510


The PCI card was from another computer I had a while ago, and I use it as a wireless connection as the motherboard does not have one. Also, why would the second X16 slot be running in X4 mode? It seems like this motherboard would have it at least in X8 mode, as most of the X16 slots are taken up by GPUs.
 

jb6684

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This motherboard uses the 970 chipset

Ah, wireless support. A cheap work around would be to buy an external USB Wireless adapter....

On lack of Dual GPU support (MB link)
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131767

Here's more detailed answer on AMD 970 chipset (you have) vs 990FX chipset (you would need for true CF/SLI support)
http://www.hardwaresecrets.com/article/ASUS-M5A97-R20-Motherboard/1772

Simply put, the AMD 970 chipset ONLY supports x16 / x4 (yeah, it's kinda dumb for them to split 20 PCI lanes up like that, but, they did. I bought an Intel board that did x16 OR x8 / x4 in splitting up their total of 16 PCI lanes (they used the on other lanes to support 6Gb/s SATA thou...))

Hey, do some bench marks with single vs dual GPU and see if you're gain any extra FPS..... If your NOT seeing much you could replace the MB. Or, return one and sell off the other GPU and get a single more powerful GPU. Which ever is cheaper for you....
 

jb6684

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Oh, some MB also shut off the PCI slots PCI lane(s) when you install that 2nd GPU...... (I didn't research that in detail as I felt that second GPU would be coming out of your system soon as it wasn't going to gain you much. My Intel board shut off the 6Gb/s SATA ports when I installed MY second GPU in it. And, like I said I junked that MB, and was none to happy about how they allocated their PCI lanes...)

 

Blade Systems

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Sep 10, 2013
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I'll download a test program and see how much I gain from CF. If it's not much, I'll probably return it and get something else that has better performance in one card. Thanks for the info.
 

Blade Systems

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Sep 10, 2013
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I did some tests and found very little improvement, nowhere near what the first 7850 got me over my 6770 (I'm currently working off of this card as I sell the other two), so I'm going to get a 7950 or 7970. I also have tried the wireless card in the other port and it did not work.
 

jb6684

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Yes, your motherboard does Not support Dual GPU's due to the limited number of PCI-E lanes on the second slot (see above). So, your best option is to go with the most powerful single card you can afford.

NOTE: that does include GTX690 and AMD 7990 "dual GPU's" on a SINGLE card. Those will perform perfectly in a single PCI-E slot that you have..