Topic: What is the MAX possible pci-e slots on a mobo? What is the bottleneck on mining (Read 3536 times)
August 17, 2011, 06:48:03 AM
I use a Gigabyte GA970-D3 that only cost $100 and has 5 slots. I'm only using 2 slots right now but I'm *fairly* certain using the other 2 or 3 will work ok. This seemed like a good deal at this time as it's a recent board and has some other nice features.
August 16, 2011, 11:56:37 AM
PCIe switches exist, and have been used successfully for GPUs, but it is not a cheap or high volume thing.
August 16, 2011, 08:48:37 AM
Wow... I didn't know that about mining... that you could use the 1x slots... Thanks for the info.... but that board is getting some bad reviews...
How much are the extenders and where do you get them?
How much are the extenders and where do you get them?
I have bought from this guy several times and have had no problems. http://cablesaurus.com/
August 16, 2011, 05:39:51 AM
Wow... I didn't know that about mining... that you could use the 1x slots... Thanks for the info.... but that board is getting some bad reviews...
How much are the extenders and where do you get them?
How much are the extenders and where do you get them?
August 15, 2011, 04:56:05 PM
... i think the most cost effective one is the 890FXA-GD65, has 6 pci-e slots for around $150. for anyone wondering what the OP is referring to, it's the motherboard and build from this thread:
https://bitcointalksearch.org/topic/pics-inside-custom-built-8-card-rack-34174
I tried and tried to get a MSI 890FXA-GD65 mobo to support more than three GPUs, finally had to RMA it back to Newegg as defective. Replaced the PSU with an Antec HCP 1200, went to two powered PCIe extender cables and it still wouldn't support four cards (verified good GPUs) at a steady hashrate. Too bad, it would have been sweet to hang six cards on it :-( https://bitcointalksearch.org/topic/pics-inside-custom-built-8-card-rack-34174
August 15, 2011, 11:23:28 AM
Thier is ABSOLUTLEY NO PERFORMANCE LOST when using Pci-E x1 2.0's FOR MINING
August 14, 2011, 11:08:20 PM
Wait I'm confused.. that looks like it only has 2 pc-e slots.... you don't need the FULL slot for the gpu's? you can use just the 1x mini slot?!
August 14, 2011, 10:04:09 PM
Wait I'm confused.. that looks like it only has 2 pc-e slots.... you don't need the FULL slot for the gpu's? you can use just the 1x mini slot?!
August 13, 2011, 10:57:03 PM
yeah that motherboard i'm using is a bit expensive, i bought it new. it's a 7 pci-e slot board that costs $280, there's only 1 board that has more pci-e and that's the MSI big bang Marshal at $400. yeah that one extra pci-e slot is definitely not worth the extra $120.
i think the most cost effective one is the 890FXA-GD65, has 6 pci-e slots for around $150. for anyone wondering what the OP is referring to, it's the motherboard and build from this thread:
https://bitcointalksearch.org/topic/pics-inside-custom-built-8-card-rack-34174
i think the most cost effective one is the 890FXA-GD65, has 6 pci-e slots for around $150. for anyone wondering what the OP is referring to, it's the motherboard and build from this thread:
https://bitcointalksearch.org/topic/pics-inside-custom-built-8-card-rack-34174
August 13, 2011, 10:31:40 PM
Thanks...
It was actually you who got me asking this question.. I saw your 7 card rig and was impressed. Nice work, the mobo is a little too expensive for my blood though.
It was actually you who got me asking this question.. I saw your 7 card rig and was impressed. Nice work, the mobo is a little too expensive for my blood though.
August 13, 2011, 10:28:22 PM
no point in making more than 8 pci-e, current drivers can only address 8 GPUs. boards with all 8 slots come with a price premium, just like a 6990.
for gaming, the bandwidth does play a small part in performance, but for mining or other distributed computing, pci-e bandwidth is not important. there are limitation to addressing full x16 bandwidth, that's why some gaming boards that has more than 2 pci-e x16 slots need a separate NF200 chip.
it's not worth it for motherboard manufacturers to make boards with 8 pci-e slots just to tailor it to miners because the demand for them is relatively small compared to the total motherboards sold for all other systems. it's nearly impossible for an independent person to make this kind of board themselves because it'll require a lot of equipment and resources/outsourcing to actually get it done. these custom boards will also carry a premium price for the amount of R&D that's required to properly make them.
for gaming, the bandwidth does play a small part in performance, but for mining or other distributed computing, pci-e bandwidth is not important. there are limitation to addressing full x16 bandwidth, that's why some gaming boards that has more than 2 pci-e x16 slots need a separate NF200 chip.
it's not worth it for motherboard manufacturers to make boards with 8 pci-e slots just to tailor it to miners because the demand for them is relatively small compared to the total motherboards sold for all other systems. it's nearly impossible for an independent person to make this kind of board themselves because it'll require a lot of equipment and resources/outsourcing to actually get it done. these custom boards will also carry a premium price for the amount of R&D that's required to properly make them.
August 13, 2011, 09:56:51 PM
So are any companies catching on to this bitcoin or any other massive calculation folding things where someone wants a lot of GPUs working.
I know the current max on any board I have seen is 8, on the msi big bang something... but it's a $400 board so kind of ridiculous for mining, and you HAVE to us extender cable because every card nowadays is a double slot card.
Is there an actual math limit to how many pci-e slots a company could put on a mobo? Do the cards actually hog up the bandwidth of the motherboard or are they just sending tiny bits of data.... like - GPU gets huge cryptography hash... works on it internally all on the GPU, then sends the small answer back... or are the GPUs really hogging up the motherboards resources / bandwidth when they are hashing?
I'm still confused by this and wondering if there is some way to daisy chain a ton of cards on one motherboard or if some company / person could see the profit and make a custom mobo for mining with say 16 pce-e slots or is this in no way possible? Or introduce GPUs with wireless connections?
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