Motherboard with 3 x PCIEx16 Slots or x1 is ok?

polarhei

sr. member

Activity: 462

Merit: 250

Firing it up

Quote from: eurgbp2011 on June 30, 2013, 06:46:08 PM

Would be there power issues if I use 3 x PCIEx1 to feed 3 x 5970 ?
Or GPU can take enough power from PSU cables?
Should I be worried about PCIEx16 at all?

According the PCI-SIG Document (1.0), Each PCI-E Slot (Including Express one?) provides 75W maximum power input.

The difference between x1 and x16, is preparation time. Our business (not only gaming) needs to load the needed then run. It is the current style of accelerator.

I have tested out, with proof of photos, posted on April 2013
http://www.hkepc.com/forum/viewthread.php?tid=1943790

The content was G92 and Fermi. Before I post, I have tested each with the x16. Then I use x1m to x16f convertor to test out on the Fermi (GT430), There is no differences, so you no longer worry the x16 slots based on the Taiwan Test below.

If you are not sure, Don't worry, Taiwanese provides a good proof for you. A true run test. You can use the diagram known to compare. There is no differences. Just slow loading time.
http://www.hwtools.net/Adapter/PE4L%20V2.1.html, The product is for Expresscard 34, It looks like weak,the true test unveils the truth of PCI-E express nature. The test I have watched, which helps me a lot as the test clarify our questions. I do the same thing for the above, To obtain my needs, also your needs.

So You will need x1m to x16f converter to work if you have three GPUs. In Gaming, It won't work due to the driver issues (AMD knows the fact)

What is Expresscard 34? External PCI-E x1. Does it work for you?

http://www.youtube.com/watch?v=liLAfPsLtv8

Zanatos666

sr. member

Activity: 280

Merit: 250

Sometimes man, just sometimes.....

From what I have seen, people have been able to get 6 or 7 cards mining on an individual board, it just takes some Windows tweaking (at least one post I remember specifically needing to do something in the registry in order to get the 7th card mining), and it depends on what you are mining.

BTC mining is heavy on the GPU, and higher end cards supply most of the power from the PCI-E power connectors from the PSU, where as LTC mining is heavy on the memory clock which draws much of its power from the PCI-E bus. People who dont use powered risers on LTC machines or push them too far will easily fry their boards/cards.

I think you mining with the 3 slots SHOULD be okay if you are BTC mining, I would not scrimp on a PSU at all. That much invested, spend the extra on a good unit that wont give you any issues and will easily be able to handle the power over the 12v rails.

Again, I could be wrong, but the only board I have ever fried over the years was a refurb ASUS board that was running on a cheap Diablotek PSU and fried the ATX connection.

ssateneth

legendary

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I've mined on up to 12 5970s with unpowered 1x > 1x risers over the course of 1.5 years. No problems with them.

Trillium

hero member

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Merit: 500

Quote from: r2vape on July 04, 2013, 06:22:37 PM

Hey dude, I am running a Gigabyte H61MA-D3V motherboard with 3x Gigabyte 7950. No powered risers and works fine, has done so for the last 3 months. One card in the x16 with a x16->x1 unpowered riser cable, the other 2 in the x1 slots with the same x16->x1 unpowered riser cables.

HD 7950: Thermal Design Power: 200 watts
HD 5970: Thermal Design Power: 294 watts

Because all consumed electricity is converted to heat the TDP gives a good estimate of power consumption at stock settings.

However OP can probably manage a substantial overclock from his 5970's because the card is essentially two underclocked 5870's in one. As a result the power consumption will easily exceed 300 watts per card.

I would recommend powered risers.

(Does anyone here have powered risers on their 5970's and is willing to connect a multimeter up to the riser power cable and measure the current? Then we could find out exactly how close to the rated specification (75 w per PCI-e slot) the motherboards have to dish out. Of course I suppose it will vary with the design of each motherboards power circuitry but it would still be interesting.)

BlazinBeaches

member

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The OP's cards are dual GPU and are power hungry suckers. I would only use powered risers on those. You could probably get away with non-powered. The question is for how long. It's just not worth the risk.

r2vape

member

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Hey dude, I am running a Gigabyte H61MA-D3V motherboard with 3x Gigabyte 7950. No powered risers and works fine, has done so for the last 3 months. One card in the x16 with a x16->x1 unpowered riser cable, the other 2 in the x1 slots with the same x16->x1 unpowered riser cables.

TheBitcoinMiningOutlet

newbie

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Hi eurgbp2011,

I would recommend that you use Power PCI-e Adatpers to take the excessive power load off your motherboard.

We have all of the adapters IN STOCK on our website

www.TheBitcoinMiningOutlet.com

There is a live chat feature on our site if you have any other questions

eurgbp2011

member

Activity: 101

Merit: 10

Would be there power issues if I use 3 x PCIEx1 to feed 3 x 5970 ?
Or GPU can take enough power from PSU cables?
Should I be worried about PCIEx16 at all?

Topic: Motherboard with 3 x PCIEx16 Slots or x1 is ok? (Read 2180 times)