Mining with PCI Express 3.0 Videocards on PCI Express 2.0 motherboard

[mascatul]

Hello,
I've seen a lot of rigs configurations and almost all of them have pcie 3.0 video cards on pcie 2.0 motherboards . My question is this ok ? The speed is the same ? are there any drawbacks in this solution. I'm mining litecoins for 2 months with 4 cards so i would like to make a custom rig.

Thanks

[1715312351]

1715312351

[HellDiverUK]

Yes, it's OK, as long as you sacrifice a chicken every 0.1BTC you mine, otherwise the PCI-E gods will be displeased and blow up your PCH.

[malevolent]

There shouldn't be any problems arising from this because GPUs / motherboards are inter-compatible regardless of PCI-E version.

[pyromaniac]

No matter what version of PEG you use. It's fully compatible in both directions. And speed of interface is also absolutely unimportant for mining.

[sikman]

No issues at all, I have 10 x 7950 and 2 x 7970 running in HP DC7700 Tower PC's here at work and there at least 3-5 years old, single x16 slot with an Intel Q965 chipset, and I think its only 1.0a PCI-E slot, not even V2 and there running PCI-E V3 cards

[ypsylon]

No problems here too. Was using few 7950 in 1.0/2.0 and no issues at all. Boards varied from really old 775 to 1366.

But I got rid of VGA miners. Heat was simply unbearable. 

[superresistant]

You don't even need to use the full 16x port, any riser 1xport to 1xport can work.

[ssateneth]

No matter what version of PEG you use. It's fully compatible in both directions. And speed of interface is also absolutely unimportant for mining.

quoted for truth

[erpbridge]

The one issue I can think of that you might have it that the motherboard, being of an age that it won't have PCI3 slots on it... may not be able to supply the operating power over the PCIe slots for all the cards you use. (Difference between the communications power over the pins, and the actual hashing power supplied by the 6/8 pin connectors.) You MIGHT need to get powered riser cables if you run into problems of the system crashing under what otherwise should be valid working conditions.

[nextgalaxy43]

Is 3.0 have the same power specification as 2.0?

[DeathAndTaxes]

The one issue I can think of that you might have it that the motherboard, being of an age that it won't have PCI3 slots on it... may not be able to supply the operating power over the PCIe slots for all the cards you use. (Difference between the communications power over the pins, and the actual hashing power supplied by the 6/8 pin connectors.) You MIGHT need to get powered riser cables if you run into problems of the system crashing under what otherwise should be valid working conditions.

There is no change in the power spec between any version of PCIe.

Is 3.0 have the same power specification as 2.0?

Yes.

The PCIe power spec hasn't changed since PCIe 1.0.
75W for 6 pin connector.
150W for 8 pin connector.
Up to 75W from motherboard (10W from PCIe x1 connector, 25W from PCIe x4 & x8 connector, 75W from PCIE x16 connector).
Max of 375W for dual slot card.

PCIe 4.0 may have some changes to power configuration.  It is still in draft form and not expected until 2015.

[polarhei]

Hello,
I've seen a lot of rigs configurations and almost all of them have pcie 3.0 video cards on pcie 2.0 motherboards . My question is this ok ? The speed is the same ? are there any drawbacks in this solution. I'm mining litecoins for 2 months with 4 cards so i would like to make a custom rig.

Thanks

The only drawback is the input (preparation) speed. But the performance does not affect due to the Serial nature. But usually being masked when selling something new.

I just have waken up with the video below.

I have tested that carefully. It looks like the differences between x1 and x16, only input speed in general case as we are discussing Display Card , Not SAS controller.

If unsure, Here is a video which should be enough for all people.

https://www.youtube.com/watch?v=liLAfPsLtv8&feature=player_embedded (The demonstration proves the performance is not on input speed but the CU (As AMD GPU GCN includes some ARM CPUs to concentrate the true thing)itself, which differs AGP)

SAS controller may be affected due to the lanes, but still work reasonable.