Obsidian 1000D 4xGPU loop advice

[UMUX]

Hello guys,

Being a mac user for 20 years, I switched to PC half a year ago and built my first computer after giving up on Mac pros! Mainly for animation, 3D (Cinema 4D, Octane +). The first one I built wasn't watercooled and I'm getting hot GPUs..

I'm now planning a build with 4 x 2080ti 11GB inside a Corsair 1000D case with EKWB cooling components.

Forgive me if it's obvious, but I'm still wrapping my head around it and about to place order.

I'm planning to place two radiators on front (as the case is wide enough) and one on top. I want to make sure I understand the loop correctly. If you see the attached mockup, is this correct?

Thanks so much for any feedback. It'll be challenge but that I embrace.

 

[Alaric]

Obsidian 1000D 4xGPU loop advice

Second mortgage? LOL OK, with the humor out of the way, as long as the loop starts from the reservoir the order doesn't really matter. In about 20 minutes after startup the temp stabilizes throughout the loop. Aesthetics, available space, airflow through the case, these things are generally more of a concern. With that case, space and airflow shouldn't be an issue.

With four 2080 Tis going in what appears to be a serious workstation, I'll assume lots of CPU cores and threads. Have you considered a dual loop? One for the GPUs and one for the CPU?

 

[UMUX]

Second mortgage? LOL OK, with the humor out of the way, as long as the loop starts from the reservoir the order doesn't really matter. In about 20 minutes after startup the temp stabilizes throughout the loop. Aesthetics, available space, airflow through the case, these things are generally more of a concern. With that case, space and airflow shouldn't be an issue.

With four 2080 Tis going in what appears to be a serious workstation, I'll assume lots of CPU cores and threads. Have you considered a dual loop? One for the GPUs and one for the CPU?

Thanks! Hah, no mortgage luckily. As for cores, I'm going with the i9 9900x which supports 128GB ram, but it's 'only' 10 cores. Most of the applications I use doesn't really use multi-cores well, so faster clock-speed is better. My other machine got the 7980xe 18 cores, but very seldom more than few cores triggered during work. Will be using the X299 Aorus Master MOBO.


Dual loop.. Now it's getting complicated here. Would it be necessary / much better?

Actually, maybe stupid question, but is the pump 'strong' enough to push through the 3 radiators etc?

 

[Alaric]

Not a stupid question at all. I'll preface by saying there will be some folks coming by this thread with a lot more knowledge than I have on the subject. You are planning a lot of water to move, and radiators are a restriction. Some more so than others, but all to some extent. I'll let one of OCF's experts field whether or not you need two pumps, but if it's in the budget the peace of mind isn't a bad reason. Knowing that kind of investment isn't at the mercy of one pump wouldn't be too awful.

The reason I asked bout two loops was if you had a big space heater of a CPU (18 cores or something) combined with 4 big GPUs it might be beneficial. I'm going by the things I've read and seen here along with a little research for a much smaller loop I'm putting together. Good place to get a head start on the stellar advice sure to come is here https://www.overclockers.com/forums/showthread.php/628092-The-Ultimate-Water-Cooling-Thread First post has links to more info than I can store in my head.

 

[Witchdoctor]

That looks to be an incredible build

I am sure the thermals will be outstanding regardless of the configuration. However two loops could be beneficial in my opinion.

Figuring 1000 to 1200 watts depending on the 2080 Ti's you choose is a ton of heat to disparate. The CPU pails in comparison.

putting 2080 Ti's on the two 480's and the CPU on the 360 is something I would consider, As Alaric states another pump in the scheme of things does not seem excessive

Please post some pics of this as it comes together, I am sure it is going to be epic, just hope you don't intend take this rig to any LAN parties ....

 

[larryccf]

helluva rig you're assembling - considering the financial investment you'll have in it, you might want to consider a double pump, if not for the added pressure, at least for the security in the event one pump fails - scroll down the pix in this thread on Mattman657's build https://www.overclockers.com/forums...EVGA-Z390-Dark-amp-Lian-Li-PC-V3000-Build-Log

If i had the budget, that's the route i'd go, as is, i use the "Fred Flintstone" approach, i keep ReatTempGT running, and it's alarm if temps hit 85C would wake the dead (it overrides your computer's volume controls)

definitely a nice build

 

[EarthDog]

Some good advice here.

On the redundancy part for pumps...I personally wouldn't bother. Things will shutdown before any damage is done so it isnt as much of a worry...though if you need 100% uptime it couldnt hurt.

 

[larryccf]

Some good advice here.

... Things will shutdown before any damage is done so it isnt as much of a worry........

Has intel changed it's thermal safety limit action since the days of Haswell? I recall my first build, when it hit 100C, would throttle back to 97C as the load was reduced, then climb right back to 100C and well.... rinse & repeat cycle. I was using or relying on Asus's AI Suite III performance utility for temp monitoring, and it was apparently conflicting with something in BIOS - but for 3 months i'd been rendering video files, 5-7 per day, 5 days a week for 3+ months.

i'd love to know intel now shuts down at the high limit temp

 

[EarthDog]

There is a thermal throttle limit and a thermal shutdown point several C higher. So, yes.

 

[UMUX]

Thanks guys for the input. I suspect this will be quite the machine when up and running. 4 x 2080ti 11GB should be a fair bit of GPU power

The GPUs will be used mainly when working in 3D and with Octane / Redshift render engines. And on top of this, I'll probaby pull some GPU power from another more 'simple' rig I have with 2 x 1080ti 11GB. So that should help too! This is my second build, so this is going to be a challenge. Going with acryllic as well, so I'll have to bend for the first time!

As for the pump issue. Having a backup pump does make sense. That said, I'm getting the EK-XTOP Revo Dual D5 PWM. Which, supposedly has two pumps built it, so if one fails, the other one should provide sufficient liquid flow to avoid a hardware failure.

Still wrapping my head around this and whether I should go for two loops. Most of my work is very GPU intensive, and not so much on the CPU. I placed an initial order from EKWB yesterday! Hope I got all the fittings right. Probably basic for some but for someone completely new to water cooling and without a clear idea of how I'm routing it, it's hard to say how many fittings are needed.

Here's the breakdown of all items. Not cheap!!

 

[larryccf]

tell me about it, i planned on $5-600 on my LC components, and i just hit $1000

 

[UMUX]

tell me about it, i planned on $5-600 on mine LC components, and i just hit $1000

Yeah no kidding. I wasn't expecting it to be this much, but with shipping it's almost 3k...

I only planned for push config though, but now I'm wondering if I should have push-pull on the two 480 radiators on front...

 

[tomb18]

I would seriously consider two loops. One for the CPU and one for the GPU's. Putting the heat of 4 2080' through to the CPU doesn't seem too wise to me. No matter how many rads you have you will always put the heat to the CPU. Same thing with a push pull on the rads. That won't help the CPU at all. Even under a perfect heat transfer situation, the temperature of the water entering the GPU's will be at best ambient, and then after the 4 graphics cards, really hot to the CPU.
Get another pump, and use the smaller rad for the CPU.
Tom

 

[UMUX]

I would seriously consider two loops. One for the CPU and one for the GPU's. Putting the heat of 4 2080' through to the CPU doesn't seem too wise to me. No matter how many rads you have you will always put the heat to the CPU. Same thing with a push pull on the rads. That won't help the CPU at all. Even under a perfect heat transfer situation, the temperature of the water entering the GPU's will be at best ambient, and then after the 4 graphics cards, really hot to the CPU.
Get another pump, and use the smaller rad for the CPU.
Tom

Thanks Tom. Very valid suggestions and points. Before I go for two loops, would it help if I went from GPUs up to the top 420 rad, then down to the CPU, then over to the 480s?

 

[larryccf]

i can't speak to your question re gpu to rad to cpu, as i'm not even liquid cooling my GPU (most of my software is CPU intensive, and only use the GPU to view results) but suggestion - fans work better in pull mode - push mode, with the fans close to the radiators, you get a lot of turbulene, ie air bouncing off the fins and coming back at the airstream exiting the fan, so negating some of the fans' efforts. Pull mode, that turbulence doesn't occur

something else to fold into the back of your cranium - the water pumps are magnetic impulse driven, not shaft - in researching my own system, i've come across more than a few cases of folks having high temps, only to pull their system down and finding pellets of solidified whatever forms, from the liquid coolant and picking up some metal ions (not sure if that's accurate) but the solidified pellets had stopped the impeller, which meant no water movement, even though the poster could feel the pump motor turning

that's the reason i added this unit, a digital flow meter https://koolance.com/ins-fm18d-coolant-flow-meter-stainless-steel-with-display - it wasn't a bad price, and i noticed the actual flow meter plugged into the display so i called in and spoke to their tech support to see if the display could be separated from the flow meter and mounted remotely - was told they had designed it for exactly that and the leads from the flow meter to the display are not polarized, so simply splice in whatever extra length lead i needed. Plus, between it and the digital display from the XSPC temp display, it helps "pimp" out my case

Koolance has another more intensive monitor unit, with more alarms (flow, temp, mortgage is due etc) than carter has liver pills, but it with the separate power supply push the price up to about $400 plus another adaptor to read the flow meter's RPMs, and the power supply is mounted external to your case and requires it's own wall socket.

The display unit i went with doesn't offer any alarms, but RealTempGT will cover me on that, the flow meter display is purely to help me diagnose a high temp, and identify or eliminate flow as the cause.

You ought to give RealTemp a try, it will almost cause your neighbors to come over to see what the issue is if the alarm sounds, it's that attention grabbing

fwiw

 

[tomb18]

Thanks Tom. Very valid suggestions and points. Before I go for two loops, would it help if I went from GPUs up to the top 420 rad, then down to the CPU, then over to the 480s?

I think that the GPU's need the 480's so if you want a single loop I would do GPU's to the two 480's then the CPU then the 420. That would make the most sense The CPU will be fine with the 420 and the GPU's fine with the 480's. I would also go for two pumps. Too much hardware to risk a single failure point. A failure in the CPU loop will close down the computer but I don't think overheated GPU's will. They would most likely fry.

 

[Witchdoctor]

trying to control the temps better by using a particular order will be ineffective.

Every loop will have a balance point when temps will stabilize, there is no way around this.

By controlling the heat deposited in to the loop by using a second loop for the GPU's will have a positive effect on the CPU temps

 

[EarthDog]

Yeah no kidding. I wasn't expecting it to be this much, but with shipping it's almost 3k...

I only planned for push config though, but now I'm wondering if I should have push-pull on the two 480 radiators on front...

I wouldn't push/pull. You have plenty of radiator already. This adds cost and noise for little returns.

Thanks Tom. Very valid suggestions and points. Before I go for two loops, would it help if I went from GPUs up to the top 420 rad, then down to the CPU, then over to the 480s?

no because loop order doesn't matter.

 

[Zerileous]

Glad some people came in and said loop order doesn't matter. Regardless of loop order, however, the GPUs will affect the CPU temps.

I'm far from an expert but most high end systems like this that I've seen run dual loops, even with just two GPUs. That said, if you're not overclocking the CPU then heat from the GPUs might not have a significant impact on performance. In a single loop the top radiator may have some extra capacity to improve GPU cooling, especially if the CPU is not heavily loaded. Really hard to say which would perform more optimally, however I think dual would be better overall.

In case it wasn't answered, the dual D5 is perfect for the two pumps that were discussed earlier, and I would say this loop definitely warrants it. Don't worry about push/pull, it might help a little but not likely enough to justify the cost of $250+ in fans. I'd sooner see that money go into another pump/res combo and a dual loop (single pump would be adequate for CPU + top rad).

 

[UMUX]

Thanks for all the feedback. It's been helpful.

I've got all the components now and starting the build! Now, I did find out that a 420 on top and the 480s in front ends up being to close to each other so I need to jerry rig the top radiator to the top and take out the sliding tray. As you can see in this video:

But... minor snag to get me started. Can't seem to find out how to remove the top of the case!! There's no screws so I'd like to believe it can pop off with pressure but no luck there.

Anyone with experience with the 1000D?