[Worklog] Return Of The Wall-Mounted Monstrosity: LiL PWNY

[BestPony]

Yes, this is only during folding. It depends on the WU but it pretty much never goes below 33% BUS utilisation on x16 PCI-E 3.0, and I imagine it will be even more on bigger GPUs later down the line.

[PoNyePiC]

Yes, this is only during folding. It depends on the WU but it pretty much never goes below 33% BUS utilisation on x16 PCI-E 3.0, and I imagine it will be even more on bigger GPUs later down the line.

That would surely suck because I would have to find another workaround.  Any ideas if that does happen?

[BestPony]

I would use conventional PCI-E riser cables on each motherboard slot until it can't support any more GPUs. You can buy pretty long ones if you want them, up to 500mm without a backplane.

Personally I wouldn't want to run a slot any slower than 3.0 x8, but it depends on how many PPD you're willing to sacrifice, there's probably not much difference between x4 and x8 with a GTX 1070. In the end it will come down to how many lanes your motherboard/CPU supports electrically.

[hiigaran]

Thanks for investing more money for the team PoNyePiC! I reckon you're going to see noticeable performance degradation with that PCI-E splitter though. I see up to 42% BUS utilisation on a x16 PCI-E 3.0 lane with just one GTX 1070.

Is that during folding?  I didn't see any extreme folding degradation the last time I used them.  I will certainly try to find out soon.

Yeah, this was one of the reasons why I never purchased a splitter. Also the reason why during the later stages of the PoH project, I was going to do a dual system, like I am now with the BS project. That said, there was so much conflicting information, that I couldn't tell what was true, and what wasn't.

Luckily, I've got a whole bunch of cards to measure bus usage with now!

[PoNyePiC]

Is that during folding?  I didn't see any extreme folding degradation the last time I used them.  I will certainly try to find out soon.

Yeah, this was one of the reasons why I never purchased a splitter. Also the reason why during the later stages of the PoH project, I was going to do a dual system, like I am now with the BS project. That said, there was so much conflicting information, that I couldn't tell what was true, and what wasn't.

Luckily, I've got a whole bunch of cards to measure bus usage with now!

My theory is that PCIe bandwidth was not as important a few years ago with folding or mining, but they might be an issue with new high end cards.   I do like the 3M 16x risers that run at full speed, but they are $80 each. Although I might consider it, since 6 of them would be $480, the price of one card -ish.

[PoNyePiC]

I would use conventional PCI-E riser cables on each motherboard slot until it can't support any more GPUs. You can buy pretty long ones if you want them, up to 500mm without a backplane.

I wish you wouldn't have shown me those PCIe risers from 3M. Right now it looks like that is my only option. Which means, if I wish to have a wall mounted computer like this, I might have no choice but to get their risers. And unfortunately, the cheapest I can get them is $80 apiece or more . But they should be future-proofed for several years to come, luckily.  And they are damn good looking too   

If ya'll know of any alternatives to the 3M ones, let me know.  I don't trust those $10 chinese one's on Amazon or eBay.  You can get lucky with them for a while, but I wouldn't trust a $5000 computer with them.  They have been know to burn up and take your precious hardware with them.

[BestPony]

I don't know of any alternatives without a powered backplane that are as long as the 3M ones, even 500mm doesn't give you a huge distance you could move the GPUs away from the motherboard. Sorry to have made you spend more money potentially!

[PoNyePiC]

I don't know of any alternatives without a powered backplane that are as long as the 3M ones, even 500mm doesn't give you a huge distance you could move the GPUs away from the motherboard. Sorry to have made you spend more money potentially!

I've checked.  500mm will be plenty

[hiigaran]

What exactly would you be looking for in a riser though? Well soldered connections, and good shielding, I assume. Doesn't sound like you need to spend 80 bucks to achieve that goal.

I think what kills a lot of multi card riser builds is that the PCI-e power from the mobo is not up to scratch. This is why many newer mobos with more than three or four usable PCI-e slots will come with a molex connection or two on the boards themselves. These function in the same way that the EVGA Power Boost works, except without taking up a slot.

[PoNyePiC]

I went ahead and bought a 3M riser to test out.  It is 50cm, so plenty long enough for the wall mounted build.  The 3M ones seem to be built much better than the cheap unbranded ones, which are built with cheap data ribbons.  I think electromagnetic interference was a concern with cheap risers that the 3M ones don't suffer from.  I don't think the cheap ones are suitable for running GPUs at 100% power for Folding or mining 24/7.  I bought one riser for testing, then I will buy more if everything works out 

[BestPony]

Cool beans! Looking forward to seeing how it comes together :)

[PoNyePiC]

Cool beans! Looking forward to seeing how it comes together :)

I blame you 

[PoNyePiC]

I figure I will upgrade my mobo from the AM3+ to an ASUS z10pe server board.  The AM3+ platform is getting old anyway.  I still have an old PCI slot in 2016.  Running two Xeons, the z10pe will allow me to use all 7 pcie slots a x8 to x16 with a total supported 80 pcie lanes.  It should futureproof me for a number of years to come.  In two years, I can update the GPUs without upgrading anything else.  I'm debating on how much RAM I want in it.  Folding will run fine off a 1GB RamDisk, so I may only get 16GB.

[PoNyePiC]

My riser was shipped out the following day with priority mail, so I should have it either tomorrow or Monday.   After several hours of research on the interwebs, it turns out these 3M risers are really the créme de la créme, not just some other Jane Doe riser   

When I found out that my USB risers wouldn't work for these new Pascal cards, I figured I would have to cancel the wall project. But from my research it appears these risers will fit the bill quite well. People say it's just like plugging the GPU into the motherboard directly.   They operate at PCI Express 3.0 at 16x speeds and do not require additional power cables like the other risers.  

[BestPony]

I do try not to recommend rubbish ;)