OTOY Forums

Hi,

I'm looking at getting 4 of the GTX 980 ti hybrids for a GPU render node. I was wondering if anyone had any experience building a machine like this. Specifically, which motherboards to consider, and how to install 4 exhaust fans into a case? It seems like cooling these things are very important and it's hard to know how they will all fit together in whichever case I decide to get.

Any help would be appreciated.

Hi there =) yeah, cooling matters. We've done huge article with Sebastian (aka Smicha) on my site. To resume You gain up to 30-40% of performance comparing bad aircooling with good watercooling.

As for Your choise, I'd advise not to get this route. Hybrids do cost 100€ more than regular models. For that You can get propper waterblocks so in addition to that You need pump/res (can buy combo) & at least one big rad - more than 360..

This option is more flexible as You can upgrade, mount outside have better parts etc =) full loop has it's own advantages, but I could understand why hydros look tempting =)

If, however, You would decide getting hydros, think of some custom mounting =) let's say have some cuts on the sede of Your case or so. Those tubes are limited in lengh so if You get bigger case they might be not enough to the top mount =)

So, I'd say even getting three cards pluss full loop is much more wise jump (if budget is constrained =)

Then for motherboard. As quad core is enough, You might end up with higher end z77/z87z97 mobo that would have additional PLX chip onboard - as those do have a possibility to plug thhree four way sli - with x8 configuration.

However if You would like to have better CPU for more intensive tasks there are much more X99 mobos that are worth the price, however You don't need thise (if computer is purelly for Octane - let's say a render node/slave)

So there are options, as there are with cooling =) those cards with attached aiAIOs are nice, but it's not wise to jump into them if You consider three four or more (noise, heat, limitted OC & tricky mounting among things to be mentioned).

Thank you for your feedback. I've read that article a lot, but some of it is still confusing.

I'd really prefer not to go with a full water cooled system, only because I'm not that familiar with it and all the parts seem really complicated to build. Is there a big performance difference between the hybrids water cooling, and a full loop watercooling system?

cincon wrote:Thank you for your feedback. I've read that article a lot, but some of it is still confusing.

I'd really prefer not to go with a full water cooled system, only because I'm not that familiar with it and all the parts seem really complicated to build. Is there a big performance difference between the hybrids water cooling, and a full loop watercooling system?

I could understand You, as water-cooling might seem a bit confusing upfront =) there are something like kits (that include everything You need) & the only thing left to buy is water blocks for Your specific GPUs & something to connect those =) Then You can slowly start upgrading (by adding extra radiator, better pumps, etc.)

I'll write a bit more detailed post about that & how to expand those things based on Your needs =) however, that's a good place to start if new in this water-cooling, but till want the best flexibility & results.

performance would not differ a ton, as both ways cores are cooled properly (under load You'll see ~50C in Octane). The real difference comes from flexibility, as mentioned You are going to have like four 120mm rads (with extra tanks on sides, that do limit Your mounting possibilities..)

One of key things to mentions apart from mounting is that those hybrid cards cool down only core with AIO (liquid coolers) the rest (vrms & vram) are cooled by the same fan on the card. It might be, fine, but still it's slightly better to have full cover water blocks as VRMs on some cards get as hot as core (especially if overclocked).

Gotcha, that makes sense. I'm slowly starting to see what I need to build a water cooled system, I'll probably go that route.

So here's my latest plan ...

- 4x GTX 980ti's
- gigabyte ga-z97x mobo
- i7-4790k 4-core 4.0GHZ / noctua NH-D14 cooler
- 8GB ram DDR3 2400
- Corsair obsidian 900D case
- EVGA 1600W PSU
- EK-XRES 140 D5 pump/resevoir combo
- EK-CoolStream PE 480 radiator
- 4x EK-FC Titan X Water Blocks

Some other questions I had - would it be OK to just liquid cool the GPUs in the loop, and have the CPU air cooled? If I go this route, with having a single 480 radiator be enough?

The fact that all 4 GPUs won't be using pci-e x16, won't matter much, right? Does that mostly affect data transfer speed?

This puts it around a 5k price tag, which is where I'd like to stay. What issues do you see with this setup, what would you change?


Thanks for your help!

hi,
I leave the water answers to Glimpse that is one of the biggest expert here in the forum But one thing pop ups in your choices, 8GB of RAM with 6GB of VRAM is not enough, I suggest you to go for minimum 16GB, better 32GB, otherwise the system can go in paging during the voxelization phase with high polygons models
ciao beppe

agree with Beppe, 8GB is bit too low.. I do see Octane alone taking 10+ GB from time to time coupled with 6GB vRam cards. if You cooking something heavy in the background that easily 10GB..- thus for workstation (not for slave) I would recommend even more than 16GB., but it might be ok to start..8GB is too little..& keep in ming PC acts very sluggishly when You're near the edge..

to cool CPU on air is fine, though I don't know if it's wise as good heatsink is going to cost You no less than water block & You'll have more troubles to fit everything, as CPU heating might come in a way of water-cooling path - look through some pictures around, but I guess first card's tubes might be impossible to route because of that big Noctua piece, so I would not advice.

Single 480, & PE might be enough to lift of, but it would not give You the best temps & leave You to spin fans bit higher - what defeats the purpose of water-cooling as You might not get so much of Overclocks, relatively high temps & more noise..If You're planing to get radiator separately I'd say thicker XE would be better idea, & I'd think about second rad..just to lower down noise & for better temps..

CPU is ok, PSU is a bit overkill, but could be totally justifiable =) as power delivery does matter. But for motherboard, I don't know..it's meant for 3cards - it would be a waste to put four..Yeah You're right saying that render performance is not influenced, but building 5k rig that puts x16 cards on what x1 slots? doesn't feel right..I'd say take three cards route or change motherboard.

900D is one of best cases You can easily get for water-cooling. It's huge, spacious enough to put everything inside & so on. Not on par comparing quality with something like CaseLabs, but for those You need to pay twice. The question again, whether You need something like that? isn't it a bit too big for You single rad route? (or You already start thinking about upgrades? =)

Pump might be enough to push liquid through, but for sake of redundancy & letting it run at slower speeds I'd get pair (but again You can upgrade in the future =) if You have any plans for that - as mentioned, sometimes it's completely fine to start low & then tweak things out =)

so, I do see few paths here:

(A) go to three liquid cooled 980Ti that is going to cut Your expenses & leave You some budget for upgrading radiator, getting better motherboard & more RAM. 980Ti on air would give You ~120, while under water close to 150, thus technically with 3 GPUs under water You get performance of nearly 4 GPUs, but with lower noise, less heat (40-50C instead of 80C).

(B) go four cards without any watercooling - performance will be the same, You'll keep spending in a similar level (again, upgrading RAM & motherboard is advisable).

(C) route is more like an option for upgrading (B) later or as an alternative to go with (A) right away - choose external radiator option, adding something like Mora (360/420) radiator. This will leave You a possibility to choose much smaller cases, & gives You cooling performance (9x 120 or 140 rad/fan space that could be configured in PushPull if You wish).

So, I don't mean to mess things up too much, but Believe 5k is not so small sum to spend it loosely & it's better too choose path that would offer You best value - saving in places where You really shouldn't..isn't the best choice, nor right investment, as You could have more headache on the long run than for choosing this route than any benefit =) hope that makes sense - tried my best to explain few things here & there.

Good news!
You'll get Win 10 for combine VRAM cards DX12 and you'll get 24GB VRAM (4x6GB).

our tech guy recommends:
Asrock Z97-Extreme9 and Chenbro RM41300G (8-slot version).

hope this helps.