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Topic: Mining with PCI Express 3.0 Videocards on PCI Express 2.0 motherboard (Read 17579 times)

sr. member
Activity: 462
Merit: 250
Firing it up
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.
donator
Activity: 1218
Merit: 1079
Gerald Davis
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.
newbie
Activity: 11
Merit: 0
Is 3.0 have the same power specification as 2.0?
legendary
Activity: 954
Merit: 1000
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.
legendary
Activity: 1344
Merit: 1004
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
legendary
Activity: 2156
Merit: 1131
You don't even need to use the full 16x port, any riser 1xport to 1xport can work.
newbie
Activity: 27
Merit: 0
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.  Smiley
hero member
Activity: 572
Merit: 500
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
hero member
Activity: 639
Merit: 500
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.
legendary
Activity: 3472
Merit: 1724
There shouldn't be any problems arising from this because GPUs / motherboards are inter-compatible regardless of PCI-E version.
hero member
Activity: 1246
Merit: 501
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.

newbie
Activity: 17
Merit: 0
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
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