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Watercooling water flow, when is enough?

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Last response: in Overclocking
August 6, 2005 12:29:33 AM

I'm in the process of installing watercooling on my PC. I have 3 waterblocks (for CPU, GPU and NB) a large "3x120mm fans" long radiator and 10/8mm tubing. I have a Hydor L30 (1200 l/h) pump. I also have an additional Hydor L20 (700 l/h) pump. My question is, will a single L30 do fine or connecting an L20 in cascade is advisable?

More about : watercooling water flow

August 6, 2005 2:06:11 AM

its generally good not to run two pumps of different power in series. can you please tell us what the blocks are so i can judge amount of restriction it provides. the higher the restriction, the more powerful of a pump you need. and usually, you don't need a NB block. as far as L30 goes, its very under powered, i suggest you spend money on a better pump.

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 6, 2005 7:44:12 AM

L30 is underpowered? There's only one more powerfull than it, it runs at 1600 l/h I think, but it's 12V and Hydors are 220V (more silent, more durable). I unfortunately do not have access to ALL the optimal pieces in this department. The Waterblocks for CPU and GPU are both by Thermaltake, one is from Big Water set and the other is Aquarius II. The NB waterblock is produced by a local (German) company - Alphacool, it's rather thin (14mm thick). The radiator is Black Ice Pro III series. The inner threads of the holes on CPU and GPU adapeters I believe are 1/8'', on NB they're 1/4''; so these will be 1/8'' to 10/8mm and 1/4'' to 10/8mm compressions. On pumps and radiator they also are 1/4''. I have three pumps, two L20 and one L30.

Hmm ... I could take one waterblock out of the loop and have a separate L20 running it, the problem is how do I cool it? I don't have another radiator, nor is there space in the case for one (have had nightmares fitting that Black Ice and the pump into my case).
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August 6, 2005 11:06:22 AM

I sure did, but have no acces to it, unfortunately. Obviously, 1700 is better than 1200, but that's what I've got. The shops I can buy from only had L20 and L30.
August 6, 2005 6:40:38 PM

So, you're basically saying that L30 will not provide enough flow and my watercooling won't work? :( ((
August 7, 2005 12:04:37 AM

Hmm, I guess I'll have to leave the NB alone then, it already has a small heatsink and a fan (default ones), can't install anything bigger really since the PCI-E card will be blocking the way. Too bad, I wanted to have a complete system, but it's OK, next time around I'll have more experience and (try) pick up better items, few get it it right the first time. Thanks for the help, really appreciate it. *thumbs up*
August 7, 2005 4:13:50 AM

What kind of rig is this, Intel or AMD? If I were you I wouldnt buy a pump from any vendor that deals in PC cooling. Pet shops have much higher quality pumps at much lower prices. Using all three blocks is fine as long as you have a pump that will push through all of them. If your going to use three blocks you will need to use a large resivior. One around 2 Gallons will be enough.

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<A HREF="" target="_new">#2 CPUZ</A>
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August 7, 2005 5:28:46 AM

exactly, most marine pumps are higher quality than PC cooling pumps... assuming you can find quality marine pumps. i suggest iwaki pumps.. very high quality, high head pressure, it can take just about anything you throw at it.

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 7, 2005 12:14:27 PM

It's an AMD rig. DFI Lanparty motherboard, Athlon X2 processor.

So, you're saying that it's either: L30 and two blocks (CPU + GPU), or anything I want but a large pump is a must?

Can someone explain the function of reservoir, please? What does it do? 2 Gallons is like almost 8 liters, it's HUGE, what is it for?

Another problem is space, since the Black Ice Pro III is so outrageously huge, it occupies all the space on the case floor. L30 fits in in the very end OK, but anything bigger would cause trouble and I was kind of hoping of keeping it all inside the case.

The crap thing is that I've already ordered the NB waterblock and paid for it (via a bank transfer), so the situation is kind of rigid, I can hardly change the order now, would suck if in the end it comes and I never use it.

But thank you for your help, it's better to leave one part unused than to use all and cause a malfunction of the entire PC.
August 7, 2005 12:20:39 PM

I do not have any first hand experience water cooling. Forewarned.

But I would think a reservoir is not as important if 24/7 operation is used, certainly not as much as a good radiator to cool water back down after running across water blocks and generating heat.
Would be nice to have that radiator have thermo-cooling to drastically drop temp, but that is more complex.
I assume the 2 gallon reservoir is to have a larger amount of water mitigating the heat transfer to the water.

<pre><font color=red>°¤o,¸¸¸,o¤°`°¤o \\// o¤°`°¤o,¸¸¸,o¤°
And the sign says "You got to have a membership card to get inside" Huh
So I got me a pen and paper And I made up my own little sign</pre><p></font color=red>
August 7, 2005 4:29:56 PM

Why spend so much on those eheim and hydor pumps when you can get a Via Aqua pump for much less?
I found many on Ebay for really cheap.
This link:
shows that they have the best price/performance ratio.
August 7, 2005 9:52:03 PM

It's just the 'VIA' part... :evil: 

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August 8, 2005 12:46:17 AM

the res is there for easly filling and a buffer for teh pump

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 8, 2005 11:21:28 AM

I see, but basically I can do without it, can't I? On the other hand it's another item in the loop that would make the system lose some pressure. Filling the whole system with liquid will be a bit tricky, but will it work fine without reservoir once installed and running? I.e., is reservoir essential or just a commodity?
August 8, 2005 6:02:37 PM

read my guide, there is another so called "res" as the T line. basically, if you don't want to mess with the space the res takes up, a T line should serve you well. and yes, i see res as a very crucial part of a water cooling loop. without it, you can't really fill your system. and when running, a good amount of water before teh pump is always good if you have a high powered pump (aquaxtreme 50z, d4,5 iwakis... or any other powerful pumps). and taking the res out after you filled your system is... well difficult. because you'll loose water in the process and without the res you can't fill it back in. and if your pump runs with air bubbles in it all the time, it'll break down in no time.

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 8, 2005 7:02:14 PM

Equivelent of Elheim 1048

But isnt the L30 also the equivalent of the 1048?

BTW I used an L30 in a full tower case with 2x120mm radiator, GPU, CPU and northbridge blocks and it seemed to work ok.
August 9, 2005 4:50:31 AM

working "okay" doesn't mean everything's fine. depending on your water blocks, for the L30 to actually "work" in a sense that your stuff doesn't over heat, it'll mean that your blocks are relatively non-restrictive. and that usually means the blocks arn't all that good. for you to increase your performance dramatically is to buy a better pump, better cpu block, and loose the NB block.

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 9, 2005 12:43:52 PM

I only have experience with my waterchill KT12-L30 kit, so I cant say that im a expert. All I know is that when I took my GPU block out, my CPU temps didnt change much. Which suggests it wasnt having a massive impact on flow rate.
August 9, 2005 4:29:36 PM

there is more variables in the temperatures besides the flow rates. if both blocks are relatively unrestrictive (they have to be), then the flow wouldn't change that much by removing the GPU block. the flow does increase when it passes through the cpu block, but not by a lot. and usually, the performance of non-restrictive blocks does not increase that much when flow increases.

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 10, 2005 12:43:14 AM

But I would think a reservoir is not as important if 24/7 operation is used, certainly not as much as a good radiator to cool water back

I thought so to until I tried a large Res. Once you get in the 2 Gal size the radiator becomes less improtant. In fact, it doesnt take much more than this to do away with the radiator all together.

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August 10, 2005 1:13:39 AM

100 dollars is really pushing it, it means that you need to savage parts and get cheap stuff via what ever you have (ebay.. junkyard.. you get the picture). something that you really can't bypass is the cpu block, which will cost you a good 40 dollars or so. and plus, if you are also going to savage heater cores, then expect it to be loud. there isn't that many thin heater cores out there that will allow for quiet operation... so your basically screwed with the 100 dollars. if tahts all you have, then get some good air cooling, u'll be surpised how well it works.

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 10, 2005 12:12:51 PM

is the thermalrigt xp120 the best air cooling available?
August 10, 2005 3:25:33 PM

You can not get unanimous agreement on any component, this is how wars are started. [you must be warmonger]

<pre><font color=red>°¤o,¸¸¸,o¤°`°¤o \\// o¤°`°¤o,¸¸¸,o¤°
And the sign says "You got to have a membership card to get inside" Huh
So I got me a pen and paper And I made up my own little sign</pre><p></font color=red>
August 10, 2005 6:56:33 PM

basically, yeah it is

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 19, 2005 10:47:26 AM

Guys, thank you all for answering. The thing is:
- Hydor L30 or (2x Hydor L20) is the best I have available to me, I can't go and pick anything I like.
- Thermaltake BigWater CPU Waterblock is the best available (the only one really), and so is the Thermaltake Aquarius II GPU waterblock.

The radiator I have is big and seems to be of high quality (Black Ice Pro III), I have three 120mm fans mounted on it which do some 134 cubic meters per hour of air flow (each).

10/8mm tubing.

I'm placing the radiator on the floor of the case (as there is no other place for it inside the case). The pump is near the radiator, also on the floor.

Do you think the loop Hydor L30 --> CPU Block --> GPU Block --> Radiator --> Hydor L30 will work well?
August 19, 2005 12:06:01 PM

Have you looked at the zalman reserator?
August 19, 2005 3:22:41 PM

I'm staying in Spain for a while and way south, can find no fancy stuff here, have to order everything from Germany.
August 19, 2005 6:02:40 PM

XD german blocks = restrictive as hell. so i guess if you can't find anything else besides that, then your good to go. don't order german blocks with the l30 or you'll be looking at barely any flow.

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 28, 2005 7:54:03 PM

:)  Are they? Didn't know that. Anyway, both waterblocks I have are by Thermaltake. From the pics I did notice that the German blcoks have a rather comlex inside structure that looks a bit suspicious in its water flow capability.
August 28, 2005 8:50:09 PM

but german water cooling is not flow dependent, meaning even with low flow, it still performs.... but i still say stay away from it, because you'll get better performance using high flow systems with restrictive blocks

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 28, 2005 9:50:21 PM

From the setup I described, are there any chances it won't work?
August 29, 2005 4:55:32 AM

i would seriously advise you not to hook up 3 restrictive german blocks onto one poor little l30... it'll simply die. your flow rates will be well below 1gph. can you get any other blocks? i would think a swiftech 6002 will go well with a weaker pump

<font color=red>gforce mx100/200 @ 230/440 =]</font color=red>
August 29, 2005 6:08:46 PM

Hmmm, I have two Thermaltake blocks, as far as I know those are American? The CPU block is the same as in Big Water cooling set, and GPU block looks similar (smaller) too.

And I have my first problem: I have connected everything and voila! - my computer booted up from the dirst press of the button. I was not installing Windows yet, just looking around BIOS, watching diagnostics. CPU temp was around 36 C (not accurate as I for now have just put the sensor "near" the CPU - on top area between the mobo and the waterblock). Anyway, the cooling system has all of a sudden begun to show bubbles running through the tubes. I have assembled and filled the system OUTside the PC and then carefully installed it inside the case. I find it improbable that there is a weak connection somewhere - it has been working on my table for a couple of hours - no problem. I have three questions:

- Where are they coming from? I can't determine if the amount of air is constant not. (Maybe some residual air from inside the radiator / pump?)

- How do the bubbles affect the cooling?

- Any simple way of removing them (i.e. without unmounting the whole thing for the third time ...)?

- Can the pump break with bubbles in the system?

- Can I just ignore them? ...

I's kind of desperate, I've been doing this PC for a long while already, everything seemd perfect and this just annoys ... bubbles also give noise which kind of scares away from turning the system on. Please advise and help. Thanks.
August 29, 2005 7:41:57 PM

Answered in other thread.

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