Crossfire Question

[Clearfly]

My motherboard has only 1 PCI-Express slot, currently with a Radeon 5850 running.

I've have plenty of room in the case and spare power cables to run another 5850.

For bitcoin mining can i crossfire a second card, without it actually being plugged into a PCI-Express slot?

[crazyates]

Short answer: no.

Long answer: no.

[Clearfly]

Short answer: no.

Long answer: no.

How's this guy done it then?
http://www.youtube.com/watch?v=TBXBB5sy5sA&feature=BFa&list=PLFDC8D564B55D6D7D

Notice the Graphics card stuck in Polystyrene

[tacotime]

Analogy: You have a car with four wheels and you're missing one but you found a tire but don't have a rim, can you still drive the car?

It's not hard to run 5 cards on a motherboard with 5 PCI-e slots:
http://www.newegg.ca/Product/Product.aspx?Item=N82E16813131644
http://www.ebay.com/itm/PCIe-Express-x16-Riser-Card-Flexible-Extender-Cable-/160883297529?pt=PCC_Video_TV_Cards&hash=item2575644cf9

[Clearfly]

Analogy: You have a car with four wheels and you're missing one but you found a tire but don't have a rim, can you still drive the car?

It's not hard to run 5 cards on a motherboard with 5 PCI-e slots: http://www.newegg.ca/Product/Product.aspx?Item=N82E16813131644

Or you do what i just did and google a 'pci-express splitter'
I wonder if something like this would work:

http://www.amfeltec.com/products/x1pcie-splitter3.php

[tacotime]

Analogy: You have a car with four wheels and you're missing one but you found a tire but don't have a rim, can you still drive the car?

It's not hard to run 5 cards on a motherboard with 5 PCI-e slots: http://www.newegg.ca/Product/Product.aspx?Item=N82E16813131644

Or you do what i just did and google a 'pci-express splitter'
I wonder if something like this would work:

http://www.amfeltec.com/products/x1pcie-splitter3.php

Good luck with that, it's hard enough getting things up and running without a splitter in my experience, and it costs less to buy a new motherboard anyway.

https://bitcointalk.org/index.php?action=printpage;topic=16174.0

(Google harder)

[Clearfly]

PCI-e splitters seem difficult to get hold of but this PCI - PCI-e Adapter looks like a cheap solution.

http://www.ebay.com/itm/PCI-PCI-E-PCI-Express-16x-Bridge-Riser-Card-Adapter-/150736952226?pt=LH_DefaultDomain_0&hash=item23189f5ba2

[tacotime]

PCI-e splitters seem difficult to get hold of but this PCI - PCI-e Adapter looks like a cheap solution.

http://www.ebay.com/itm/PCI-PCI-E-PCI-Express-16x-Bridge-Riser-Card-Adapter-/150736952226?pt=LH_DefaultDomain_0&hash=item23189f5ba2

Some people use them, yes, but keep in mind you're pumping way more wattage through a PCI bus than was ever intended.  I believe PCI is only spec'd to 25w.  Whether or not the motherboard can handle that for prolonged mining is questionable.  Bad things happen when you pull more power through a board than it's intended to.

Easy mode is to just buy a board with the appropriate number of PCIe x16 slots.

[Clearfly]

I hear ya, but new mobo = new CPU and new memory as well.

I have 4gb Ram, 2 old socket 478 motherboards + 2 Pentium 4's floating spare.

Would a 5850 still pull 75w though the PCI bus even though is has 150w power supply going directly to the card itself from the PSU?

If so i guess i could couple the adapter with one of these PCIe ribbon cables with a molex plug on it:
http://cablesaurus.com/index.php?route=product/product&product_id=12

That would cost me about $40 in total which is much less that a new Mobo/Cpu/Ram combo.

[Jack1Rip1BurnIt]

You don't need the molex plug on the riser cable with those smaller less power hungry cards. 5970s and 6990s is are the only cards I really see people need those types of risers...I guess there is always exceptions though.

[tacotime]

You don't need the molex plug on the riser cable with those smaller less power hungry cards. 5970s and 6990s is are the only cards I really see people need those types of risers...I guess there is always exceptions though.

The problem is that he's pulling through PCI instead of PCI-e though...  You might want to get one just to be safe.  If the soldered connections on the motherboard are only intended for 25w, it's probably better to pull it directly from the PSU.

[Jack1Rip1BurnIt]

The problem is that he's pulling through PCI instead of PCI-e though...  You might want to get one just to be safe.  If the soldered connections on the motherboard are only intended for 25w, it's probably better to pull it directly from the PSU.

I agree with you that it is difficult to predict what will happen. I also agree that it would be less expensive to just buy a used motherboard with multiple pci-e slots.