PCI-E Slot problem

[st4rdust]

Wondering if anybody on here might be able to help me out with a problem I'm having with the bottom PCI-Express slot on an ASRock 770DE+ motherboard. I bought it as a budget board for a mining rig since it has two PCI-E slots. I'm using two 5830s in this rig, but only one of them will show up anywhere in the Windows 7 environment. That is, GPU-Z has only one card present, CCC also lists only one card in its hardware tab. Even the device manager lists only the one card under display adapters. Now here are the facts I've confirmed:

1. Each card will work in the top PCI-E slot, no matter which one I switch into it.
2. The PSU is a 650w Apevia that, while may not be a high-end PSU, has supported two 5830s in another rig no problem before.
3. The current rig is a single-core Sempron CPU with a single SATA hard drive, two DDR2 memory sticks, and the 5830 cards. The PSU is by no means overworked.
4. With only one card in the bottom slot, the system will turn on, and the POST will beep several times, and nothing appears on the monitor, which goes into standby.

I do not have the cards connected with a crossfire bridge, but I never use one with mining rigs. I'm hoping there's some adjustment I can make to the motherboard or the BIOS to enable the bottom slot. Is there anything I can do here to bring this second slot online, or is it probably a dead slot?

[Jack1Rip1BurnIt]

On my Asrock motherboard I have to turn or flip a little card around in order to activate the second pci-e slot.  It is located in-between the two slots. I will check the website and see if you have the same thing on yours. If you wanna see what I'm talking about check out the A780-GXE 128M

[Jack1Rip1BurnIt]

Checked the website and your motherboard doesn't have the card to switch around like mine does. I also noticed that your board doesn't have a 4 pin molex on it for extra power...I don't know if this could be the problem just an observation. Do you have any x1-x16 riser cables? If you do you could try the x-1 slot and the main x-16 slot and see if that gives good results.

[st4rdust]

Checked the website and your motherboard doesn't have the card to switch around like mine does. I also noticed that your board doesn't have a 4 pin molex on it for extra power...I don't know if this could be the problem just an observation. Do you have any x1-x16 riser cables? If you do you could try the x-1 slot and the main x-16 slot and see if that gives good results.

Thank you for checking into this for me. No, unfortunately I don't have any riser cables (can you recommend a good source? I'd like to invest in a few.) and in terms of power, the connections from the PSU to the cards should suffice. The PSU is equipped with four PCI-E connectors: two 6-pin and two 6+2-pin connectors all together.

[Jack1Rip1BurnIt]

Yeah, the psu looks fine and I'm not totally sure about the 4-pin molex. My Asrock motherboard has the molex specifically for crossfire but on the other hand I have another motherboard that is decked out with 3 7950s all on the x-1 to x-16 risers and it doesn't have the molex on board. There are a lot of places you can get the riser cards from ebay so it won't be hard to get good cheap risers. The main thing you will want to pay attention to is how fast you need them. I for instance bought mine for like $3.75 shipped but they came from somewhere in China I think. Anyways it took about 8 to 10 days total for me to receive them but they worked without any problems. So if you need them faster make sure you buy from inside your country even if it costs you a little more.

Searching this is ebay gives tons of results: New PCI-E Extension Cable 1X To 16X Riser Extender Card

[st4rdust]

There are a lot of places you can get the riser cards from ebay so it won't be hard to get good cheap risers.

Thanks for the info. I've always been interested by the idea of getting some risers to save a lot of money versus buying whole motherboards for the sake of extra PCI-E slots to squeeze more graphics cards on board. What's the story with the extended ribbon cables? Is the idea to just rig up the graphics cards just any old way they can fit inside whatever case you're using them with?

[Jack1Rip1BurnIt]

Well it depends on what you want to do. How much space, money, cooling capacity you have. I personally bought a shelving thingy(can't remember what it's called) from Lowes for $19.99 and it has multiple levels that I could mount the cards to with small zip ties. Here is an alright picture of what I'm talking about when I had 3 5850s.




This particular motherboard only has 1 pci-e x16 slot and two x1 slots, and since pci-e is backwards compatible I just used three of those same riser cables. Trust me once you use them you will be like "Why didn't I do this sooner!". I just put the motherboard on a cardboard box(because they don't conduct electricity), but you could use anti static bags or whatever floats your boat. And you will need to get a momentary-on switch to turn the psu on. Here is the one I use...

http://www.ebay.com/sch/m.html?_odkw=&_ipg=25&_osacat=0&_armrs=1&_ssn=hottestdealever&_trksid=p2046732.m570.l1313&_nkw=Power+cable+and+button+switch+for+pc+replacement+on+off+switch+reset+computer&_sacat=0&_from=R40