Cheapest way to get two / more cards in MP 5,1?

[professorhaddock]

Hey guys,

I'm looking high and low for an expansion chassis for my 5,1 Mac Pro with a 980Ti in it, and all I'm finding are $2500 Cubix units. I'm wondering, is there a cheaper external solution, and if not, what would it take to get another 980Ti inside my tower?

[Collider]

A. Amfeltec splitter, B. Amfeltec expansion cluster, or C. 3m extenders. Probably others, but those are the one's I've tried. You'll need an external psu. 3 is the limit for the maxwell cards (980Ti) in the 5,1, I was only able to get 2 working reliably, but had 3 going once or twice. Ended up scrapping that whole enterprise and built a 7gpu PC (pretty close to what smicha did on his videos). Pretty sure you can fit 2 980Tis in the case (still need to run power to them), so 1 3m extender might be enough for you.

Egpus still work ok on my other macs, buying up hybrid 980Tis on eBay to run those.

[professorhaddock]

Hey Collider,

I appreciate all of the info! Do you know of a tutorial for going the 3m extender and extra power supply route? (I couldn't find the 3m online anywhere.)

And in your experience, does it sound like a jet engine with a power supply outside the case or are volume levels pretty reasonable?

[FrankPooleFloating]

EVGA Supernovas are very quiet... Mine is like an old lady blowing gently on a dandelion. I'm not sure if SuperFlower makes the entire Supernova line for EVGA, but they do for the bigger ones, and SuperFlower PSUs are the shizz.

[glimpse]

hi there!

cheapest way to get more power for mac, would be firstly topping out Your machine (pair powerful GPUs + external PSU & it could be small one, like SFXL size unit). if that's not enough, then expanding is an option as well.

However You should know couple of things first. You get what You pay. By that I mean, most of expansion boxes will set You back for at least like 1-2k$ & the reason being is that those have 8 or even 16X PCIe upstream interface - actually worth the price, but well.. You might be looking for something cheaper & if that's the case, look for something like splitters just keep in mind that You would need to figure out some sort of mounting solution. GPU cluster helps to solve that, sort of..but it's still a bit messy for some, so Guys keep putting this into some box.

alternatively, You can grab backplane. This actually have holes drilled that are compatible with (m)ATX cases, so You can mount this into any regular case, add power supply & You would be good to go. You can work up to two cards on air, or up to 4 if You single slot mod & watercool them. Bellow You can see some shots based on this backbone in a case with custom watercooling.

it works great, on air, with gap in between You can get cards cooled just right. Macs seems not to control GPU fan speed properly so from something like TitanXs You can expect like 130 on first run & down to 111 after a while (980Ti would be a bit slower).

As for slower interface. if You push higher resolution to render GPUs might start to have some gaps in utilization & You would notice some speed drops, but that comes to the point - You get what You pay. Another thing is that some functionality like baking might cause system shutdowns (kernel panics) so if You really care about stability, better build a proper render node.

I haven't looked to this lately but seems that macs work best on Maxwell cards. Those are getting harder to find new, but if You would look around You can get pair of second hand TitanXs for instance - just few days ago guy on our community was selling pair of those for 900EU (in total, with shipping). So if You would get a good deal, You can grab a pair of good cards + PSU + backplate & case for like way less than 2k$ & that would lead between 220 - 260 in terms of OctaneBench, 12 GB of vram. If You want to cut some corners, then 980Ti is a great option as well. Try to do some research if Pascal based cards are now supported..maybe You do not need to stick with Maxwells anymore, however for the price some cards are sold now it really hard to resist..I almost bought those two TitanX I mentioned..but then realized 1080Ti is already coming & then there will be other expenses..so passed that.

Hope that helps ;) Let me know if You would have any more questions regarding to this =)

[Collider]

Hey Collider,

I appreciate all of the info! Do you know of a tutorial for going the 3m extender and extra power supply route? (I couldn't find the 3m online anywhere.)

And in your experience, does it sound like a jet engine with a power supply outside the case or are volume levels pretty reasonable?

Hey - did a quick search, also found this:
https://www.newegg.com/Product/Product. ... -_-Product
(there is also a longer one - 600mm)

Haven't tried the thermaltake above, but what you are looking for is a high quality SHIELDED riser cable... the cheap ass ones you find on eBay will give you fits, and are 6 dollars for a reason. Some of the reviews aren't that great, so no idea if it works or not...

Digi-Key is the only place I know of that carries the 3m one:
https://www.digikey.com/product-detail/ ... ND/3641403
(poke around, different sizes/prices etc...)
ok - just found this - couple more places to buy the 3m - https://www.reddit.com/r/buildapc/comme ... st_option/

The idea is to just plug the riser extender in one of your PCIE slots, hang your video card outside your computer however you want (I had mine lying on the floor for a while while I was testing, but there are lots of ways to enclose, or brackets you can make or buy), and power it with a psu. And maybe blow some fans on it - either computer fans, or a normal box fan - doesn't matter, you just want to keep the air flowing and keep the cards a cool as possible. I love the EVGA G3 psu - super quiet and super tiny. The noise from the rest of the rig is up to you - it's all fan noise. The Amfeltec riser splitters will allow you to hook up more than 1 card to each pcie slot, and for about 500 bucks, the cluster will allow you to hook up 4 cards and makes it easy to secure and cool them.

The boxes Tom is talking about are great - but will only work with multiple non-maxwell cards if you want more than 2-3 (again - apple doesn't work with more than 2-3 980Tis - just a limit you have to deal with). But wow, he makes beautiful looking machines, huh?

[Chrmez]

EVGA Supernovas are very quiet... Mine is like an old lady blowing gently on a dandelion. I'm not sure if SuperFlower makes the entire Supernova line for EVGA, but they do for the bigger ones, and SuperFlower PSUs are the shizz.

Not the 1300W version. It's a great PSU, but very loud so not sure that is one I'd recommend. Heard only good things about 750W though.

[FrankPooleFloating]

Where did you get that? I just found three reputable sites that state that the Supernova G2 Gold 1300W is OEM'd for EVGA by Super Flower... And it's as quiet as a bunny wiping his ass with velvet.

[Chrmez]

Where did you get that? I just found three reputable sites that state that the Supernova G2 Gold 1300W is OEM'd for EVGA by Super Flower... And it's as quiet as a bunny wiping his ass with velvet.

Do u have the links? I don't think I've read a single review that didn't mention the noise level

Also..
http://www.overclock.net/t/1544679/evga ... 300w-reall...
https://forums.anandtech.com/threads/ev ... -1300-is-n...
https://forums.evga.com/1300-G2-fan-is- ... 254551.asp...

Review from techpowerup.com
"The fan profile is quite relaxed at even over 40°C ambient, but the fan is a speed and noise demon"

[FrankPooleFloating]

Why read others' reviews when I have one sitting two feet away from me?... I think it might very well be the quietest thing in my case, aside from my 200mm fans. While rendering with all three GPUs, it does rev up a some.. so does everything else.. but if I put my ear right against it, it's much quieter than the rest of the beast. So I think we can conclude that they are indeed made by Super Flower, and mine is pretty dang quiet, in my most humble opinion.