Need some advice regarding radiators

[lol]

I'll try to keep this short and sweet.
So I am going to be watercooling 2 7990s (that's 4 GPUs) (yes I am crazy and no you don't have to point that out by posting how crazy it is to have 2 7990s)

I am planning to use a single 480mm rad for that, which should be more then enough seeing as sapphire has a watercooled 7990 cooled by a 240mm (60mm thick) rad. I can't find the specs anywhere but it seems to be using a low FPI radiator from a picture shown in a youtube video. Supposedly the atomic 7990 runs 75C under load.

My question would be how much would the difference in temps be between a 10fpi 480mm rad to cool 2 7990s and a 30fpi rad to cool 2 7990s. Can anyone guess what temps it will run at?

I am fine with them running at 75C (and they will be lower since I will be using a 30fpi rad) but I am wondering if I'll have low enough temps to add a CPU to the loop once haswell-e comes out (assuming that the 5930k will be an 8core) also I will not be doing any overclocking at all (as I told you before, crazy I know <_<) fans will be NF-F12s probably running at 100% if I have to since 20dB is plenty quiet for me.

 

[SuB]

I think 4 GPU's and a CPU is pushing it on a 480mm rad personally.

 

[Nurf]

Asking for temps based on FPI is like asking "I'm buying a used car with a 2 litre engine. How fast will it go?"
In other words it's just one property of rads out of many.
That being said, with NF-F12s you will want a low FPI rad. If you make a custom loop, your temps should be way better than that sapphire card.
If you want to know if adding a cpu will work, I'd cool the gpus first and get a water temp probe so you can better estimate your rad performance. I agree with SuB that 480 rad might not be enough to add a cpu, but there are so many factors in watercooling that we can't give any numbers on temps, only opinions.

 

[alpenwasser]

TBH running something as low-power as a Noctua NF-F12 on a 30-fpi radiator is kinda
pointless. See this review for example. The HW Labs GTX only really comes into its
own once it's given some proper fan power, and the reviewer states that you would really
need something even more powerful than what he has to really unlock the radiator's potential.

If you give a high-density radiator some decent fan power it will have noticeably better
performance than a low-fpi radiator, but we're talking 3000 rpm Delta fans here and not
Noctua NF-F12. But that is going to be anything but quiet.

However, if you're sticking to the NF-F12's, a low-fpi radiator will actually net you better
performance going by that data (and that data comes from one of the most reliable
sources of W/C reviews on the net IMO), so you'd be better of with something like an
Alphacool UT60, or if you can manage push/pull and have the space, a Monsta
(the Monsta significantly benefits from push/pull).

Having said that, I'm inclined to agree with SuB, one 480 is kinda tight IMO for all that
heat. If you really want to find out, you're going to have to try it yourself though, as Nurf
has stated there are way too many factors at play here to make even halfway reliable
predictions.

Whatever you do, if you pick a high-density radiator, run some high-rpm fans on it,
and if you're going to stick with the NF-F12's, pick a low-to-mid-fpi rad, anything else
is just wasting money.

EDIT: Welcome to the forums!

 

[tinytomlogan]

What case have you got that fits a 480 dude?

 

[lol]

@alpenwasser

the reason why I am planning to go with a 30fpi rad is because as far as 480 rads go the only one that will fit in my case is 30fpi.

http://www.frozencpu.com/products/2..._EK-CoolStream_PE_480_Quad.html?tl=g30c95s570

@tinytomlogan

A fractal design define XL R2, officially it doesn't support a 480 but I did some measuring and if I get rid of the 5.25inch bays and do some modding I can fit a 480 in the front. But not any 480 the one I linked to above will just about fit.

I'd love to go for the monsta but I won't have enough room to mount the res behind the radiator because of the 7990s. I can however go pushpull with the rad I posted above, I am not sure how much it would benefit in pushpull with low rpm fans. I suppose it'll perform better since the pressure difference for the first set of fans pushing air into the rad will be bigger.

A 360 or 420 in the front and a 240/280 in the top is a possibility as well but I really want to keep the two top spaces covered up with the moduvent covers or w/e they are called to keep dust out when it's off.

I could go with higher rpm fans, since I will always wear in-ears when gaming, or I could re-use my h220 and cool the 2 7990s with the 480 rad and the cpu with the h220 and some dust filters on the top to keep the dust out.

Considering the define XL R2 doesn't have the best airflow in the world in the front (because to me it also seems like the front intake will suffer from some airflow restrictions especially with high rpm fans) I might have to end up doing that.

I was just wondering if a single 480 was a possibility since I wasn't planning on doing any overclocking and don't care about the temps as long as the coolant doesn't warm up enough to damage the o-rings or something (the tubing I am planning to use is rated for 135C max operating temp so it shouldn't be a problem, if you can run a watercooling loop at 135C without the coolant vaporizing I'll give you a cookie)

 

[Nurf]

If you can fit a EK 480 PE with push/pull, why can't you fit lets say a EK 480 XT?
You don't care about temps and your ok with higher rpm fans, so why exactly are you watercooling?
As far as WC parts not breaking, your gonna run into alot of trouble before any of those ratings become relevant.
Your plan just doesn't seem worth doing imo. You can do it, but it doesn't mean you should. With the money your sending/have spent I'm guessing it would be no problem to look at other cases, even the more expensive ones like from caselabs.

 

[lol]

If it's about the same size it will fit, which is also why I am asking for advice. I have never done watercooling before. If the radiator is longer than 520mm it's probably too big to fit in the case.

I am watercooling as a hobby I suppose. Not everything is about temps and noise levels, if you go purely for performance air cooling is better price/performance wise pretty much 99% of the time.

Aesthetics is also a big factor, personally I think waterblocks look better then most cpu coolers and gpu coolers. But that's a personal thing, for me it's important that it looks good and stays dust free.

The case isn't a problem I can easily fit a radiator in the top and a 420/360 in the front. That can keep everything cool but I want to see if it can be done with a 480 and what I'd need to keep in mind if I were to do that.

In a way building a pc is like a puzzle, some people are looking for the best performance per buck, others want a quiet build or to squeeze every little bit of performance out of the best hardware there is with extreme overclocking.

I guess with my build it's comparable to trying to make a powerfull itx system, sure you can easily fit it in an atx build but the challanges that come with a smaller build make it more fun.

 

[lol]

also regarding the fans, I know RPM affects performance but the NF-F12s are optimized for static pressure meaning they are "made for radiators and cpu coolers" as opposed to fans made for airflow.

Doesn't that mean they would perform better then normal fans that also run at 1500 rpm.

 

[Nurf]

If thats what you want to do then here is a quick recap of answers to your questions.
We can't give you possible temps, but 480 might not be enough to add a cpu. If you are set on getting the cpu added to the loop, I suggest you add it and if it doesn't work then add an extra rad.(be prepared to do so)
If your gonna buy a EK rad, I suggest the XT intead of the PE. The lower fpi is better for your fans.
Static pressure isn't a constant number and most people misunderstand how it works. If you want fans at that rpm/noise level then those fans are a good pick, thats all you need to know. Personally I wouldn't go with louder/faster fans than those and if your trying to avoid adding more rads, I wouldn't go any lower.

Get a D5 pump and some blocks that look nice. After that your pretty much ready to go for your first WC setup. Alot of questions get answers once you try watercooling yourself.

 

[alpenwasser]

Yeah, pretty much what Nurf has said. Whether or not you run a 30 FPI radiator is up to
you,
but as has been pointed out you're using neither the NF-F12's nor the radiator to its
proper potential, and a low-FPI radiator would make much more sense with those fans (and vice versa: More powerful fans will better utilize a 30 FPI rad's potential).

Despite the NF-F12's being optimized for pressure, they don't actually perform all that
well compared to other fans of similar rpm's. They're not horrible, but even Noctua
can't get around the laws of physics.

Check this review, for example (the conclusion starts @ 25:30 Min):


One a more general note, people do things for all kinds of different reasons, if you want
to W/C just for the heck of it then by all means go ahead. I have certainly cooled quite
a few PCs with water over the years which would have run perfectly fine on air simply
because I wanted to and enjoy the fun of it.

 

[lol]

<snip>

And if I were to go with the gentle typhoon AP-15s I'd be better off with the 30FPI radiator?

<snip>

Thanks for posting that video, very informative.


The case I am building in really isn't made for max watercooling potential and rad space (without modding at least) however it is optimized for silence I do not hear the 33dB fans on my H220 at all, there is a massive difference once you open the front cover. (I can hear the fans on my 7990 however)

So maybe I can go with some louder fans like the gentle typhoons and still use the 30FPI rad to squeeze more cooling performance out of that space then a 10FPI rad with NF-F12s.

I wasn't set on buying NF-F12s or that radiator for that matter, I am in the early stages of planning atm. I am waiting for haswell-e to come out then I will watercool my PC so I have plenty of time to learn.

 

[Kaapstad]

A single 480mm rad is not enough for two HD 7990s and possibly a CPU.

Including the cpu even at stock we are talking nearly 1000watts of heat to get rid of.

This is all a bad plan.

 

[lol]

Also I can fit an EK 480 XTX in my build.

What would give me more cooling potential the XTX with NF-F12s or a PE with gentle typhoons? Or an XTX with gentle typhoons?

I suppose the gentle typhoons are best used with higher FPI radiators but I am wondering how they will perform with a thicker rad with lower FPI.

 

[alpenwasser]

Well, the GT's are available in many different rpm versions, so you can suit them to pretty
much any radiator you like. And they are excellent undervolters, so you can use them
with pretty much any radiator, regardless of FPI. There's even a 3000 rpm version and
one faster one, which would probably be best in combination with a 30 fpi rad.

If you can fit an XTX I would recommend that. Which rpm version of the GT would you like
to use? Because the 1850 rpm version is not going to be that much better than a 1500
rpm Noctua.

Alternatively, you may want to look at Noiseblocker's eLoop series, they make a 2400 rpm
fan. If it turns out that you don't need that much rpm you can still turn it down to lower
rpm's, but that would give you quite a bit more headroom. Or of course the 3000 rpm
GT, however I do not know how well that performs if you regulate it to lower voltages.

 

[Nurf]

You seem to be set on getting that high fpi rad. High fpi rads need fast fans to get the benefit, but that doesn't mean a low fpi rad can't be as good in high rpms. Seems like your thinking "more must be better", but the XTX is the best option out of the EK rads if you can fit that. Even if your next question is "what about if I use 3k rpm fans", I'd still say the XTX is better because of its thickness. AP-15s on 12v (1850rpm) are way too loud for me, but your posts give me the feeling that they would be ok for you. So best combo is XTX+AP-15s unless you want to go even louder.
Like I said earlier, if you must have the cpu in the loop then there is no harm in trying it and then adding an extra rad if needed. (that how you learn, you try things out)

 

[lol]

<snip>

I think I am going to have to go with the 1850RPM version of the GTs. By the looks of it the 3000RPM version is 35mm instead of 25mm.

Actually now that I have taken a look at it I can fit 35mm fans as well, however I'd have to remove fractal's dust filter and since I want to dust filter those fans I'll have to find a different filter that isn't too thick. Was going to need one anyways for the top 2 fans.

By the looks of it there used to be charts about radiator cooling performance on skinneelabs however the site is down. I think it also showed cooling performance vs RPM for different rad sizes. Would be neat if I could use those as a guideline of how fast the fans would have to be in order to cool everything on a 480mm rad.

Did anyone save those charts or remember what it looked like for a 480mm rad? I could go with the 3000RPM GTs if it makes a big difference in performance. I always wear in-ears when gaming so if they spin up when gaming I don't care.

I will probably go with an asus mobo and it'd be strange if they didn't include aisuite with their haswell-e boards. From personal experience with aisuite I can say that fanxpert2 is really really nice for controlling fan speeds, so I can probably turn down the 3000RPM GTs to a sound level that works for me at idle as well. My current motherboard in my gaming pc doesn't have anything like that so I think the fans spin at pretty much 100% all the time (which would be 33dB)

I have not been able to successfully tell at what RPM they are spinning so far but compared to my home server (which has asus' aisuite) I noticed a giant difference, I cannot hear the home server which is on my room and on 24/7. I can clearly hear the fans in my other pc however it doesn't bother me that much even when I don't have in-ears on.

If I lay in bed and one of my hdds spins up for no reason (booting from ssd and hdds are storage only) I can clearly hear that and get annoyed by it however my case fans on my gaming pc don't bother me. So I am not that afraid of "loud" fans since as far as I can tell I get annoyed by changes in noise level much more easily then by being in a noisy environment.

 

[lol]

A single 480mm rad is not enough for two HD 7990s and possibly a CPU.

Including the cpu even at stock we are talking nearly 1000watts of heat to get rid of.

This is all a bad plan.

That's what makes it fun :lol:

It's like trying to watercool a titan in an mitx build, only I am trying to watercool 2 7990s in a full tower case. Normally you'd say get a caselabs case with over 9000 radiators, but it's fun to try and push a full tower case to it's limits.

Just means you have to carefully picks your components and be really smart about how you do it.

 

[lol]

You seem to be set on getting that high fpi rad. High fpi rads need fast fans to get the benefit, but that doesn't mean a low fpi rad can't be as good in high rpms. Seems like your thinking "more must be better", but the XTX is the best option out of the EK rads if you can fit that. Even if your next question is "what about if I use 3k rpm fans", I'd still say the XTX is better because of its thickness. AP-15s on 12v (1850rpm) are way too loud for me, but your posts give me the feeling that they would be ok for you. So best combo is XTX+AP-15s unless you want to go even louder.
Like I said earlier, if you must have the cpu in the loop then there is no harm in trying it and then adding an extra rad if needed. (that how you learn, you try things out)

Well the reason why the 30FPI rad makes sense to me is because it will have much more surface area. Extra thickness does the same but 30FPI vs 10FPI compared to a 40mm rad vs 65mm, to me, seems like the 30FPI would be a winner assuming you don't mind having loud fans. And boy will I need every tiny bit of cooling potential if I am going to do 4 GPUs and a CPU on a single 480mm rad.

Then again I am a noob so there is that.

 

[Nurf]

Well we warned you about having only a 480, we told you that a XTX is better then the PE and its up to you if you want 1850 or 3000 rpm fans.
If your posting about how you aren't taking our advice then people won't see any point in trying to help. So you have our opinions on your questions and now its up to you if you want to listen or not. I personally got a high fpi rad for my first build (thinking just like you) and was stuck with it for dimension reasons for some time and finally got a build that will fit something else. So if you want, you can make the same mistake I did.