I've noticed lately that there seems to be more and more talk about small bore setups and a growing dislike of large bore setups. I dunno maybe this war has been waging for some time, but being somewhat new to water cooling myself, its all new to me. To save myself a few paragraphs I'll throw in a pic of my current setup. For tubing I'm using 7/8" O.D x 5/8" I.D.. The reason for this is that I use 1/2" copper plumbing and the 5/8" I.D. tubing fits over the copper pipe perfectly and then I clamp it, no need for a barb. The CPU block is a home made job. And the pump is a pond pump rated at 170GPH, I'm not sure of the head ATM but its direct drive so it does quite well. Also, if it matters I'm going to have a pelt in there soon. Anyway... I was thinking on reducing the tubing size, maybe even down to maybe 3/8" ID as the 7/8" OD stuff is too bulky for my taste and is a pain to route. My concern is for the future when I add a GPU block and then maybe 2 GPU blocks in an SLI (or crossfire is it?) setup where this 7/8" OD stuff is going to be a nightmare. What I was wondering is if someone here has done tests or has come across something on the net comparing the performance of different tubing sizes. I realize that alot has to do with the design of the block, but looking at what's out there mine seems quite large, and common sense tells me that its surface area thats important to get the heat into the water. My block has approx. 36 square inches in contact with the water so I cant see it performing badly on a lower flow setup. But what do I know.
ok this has been discussed b4. Here---> http://www.hardforum.com/showthread.php?t=907411 BTW Cathar talking on there is a veteran water cooler and has designed comercial blocks as far as I know. Give it a thurugh read, it should help you with your questions. BTW very nice setup. What kind of heter cores did you use on it? I love the large bore setup you got btw. I am a big fan of large bore.
Firstly Biff, Thats a really neat setup, especially considering the bore you are using. Very good work. Now FWIW here is my take on the whole flow / tube size issue. Most of what i am about to say is speculation on my part, and educated guesswork fronm the threads i have read particularly at procooling. You are correct that surphace area is important to cooling performance, but its not as important as you think. Whats more important is the behaviour of the coolant as it flows through the block. Take the G4/5 There is no way that has more surface area than a micropin style block. All it has is holes woith littel nipples at the bottom. The coolant squirts into the holes at an accellarated rate (this can be manipulated by the jet size and pump pressure) Impingement style blocks are designed with a specific pump pressure range in mind. The formula calculates the ideal ammount of jets of a specific diameter to cause coolant accelleration to be sufficient to make the coolant work correctly. As with air cooling there is a layer, if you will, of coolant (air or water) that sticks to the surface of the block or heatsink. The jets are designed to blast that layer off the surface of the block, and increase turbulance in the coolant. Obviously getting throught that layer of stagnent coolant is important for performance but so is turbulance becasue it effectively increases the surface area of water that comes into direct contact with the base plate. Its only in the last 18-24 months that impingement has had any involvement within watercooling and probably around 6-12 months where it has become a popular method for waterblock builders to exploit. It is complicated to configure though, so i would guess that R&D cost must have increased for such blocks. Up until such time blocks were non restricitve and needed a large and constant supply of coolant to get decent performance, hence the need for high flow rates. Now, to my mind, the reason the argument is arrising again, and also the reason that people are being convinced by small bore is that top block designers (im thinking specifically of cathar - probably the most influential) are realising that people want to have smaller tubing for easier installations and have designed his latest blocks around a desired flow rate (somewhere middle of the road iirc) instead of the old ideal of as much flow as possible. This partly comes from peoples desires for neat loops and partly from the much more restrictive designs of blocks these days. Restricitve blocks also nessecitate a different kind of Pump, not one with massive flow rates but one with good head pressure.
Those are two '86 chevette heater cores. They have been modded to have the barbs on the other side of the cap. Initially this was for routing purposes, but now its more just so I can have a 1/2 copper pipe instead of what comes stock on the HC. Fivecheebs, I mostly understand the theory at least of the impingment style blocks. Although a great idea, maybe not so easy to implement for a DIYer. The one thing I can't get past though is AFAIK these blocks need a pressure difference between the in and out to allow the jets to work properly, with the output being a lower pressure. If the output is the lower pressure how will the next block in the loop perform. Pardon my limited phase change knowledge, but to me it seems like trying to take the output of the CPU evaporator and sending it through another cap tube to cool another block. Maybe this is possible but not how I understand it. I realize some people maybe "fooled" by surface are when reguarding the performance of a micro pin style block. Going on intuition alone, the micro pin seems largely ineffective to me since any pin extending beyond a minimal amount above the base will not help cooling any more since the cross sectional area of the pins isn't large enough to conduct heat all the way up the pin. So you get a large surface area block that doesnt perform as well as you would think it should. I kept this in mind when I built my block, but I'm unsure of exactly how correct this mindset is. Thats just my take on it.
My take on all of this is pretty mutch this. The higher the heatoutput of the component yur trying to cool the greater the volume of water flowing through a block. For cases like this the blocks should have chanles and not pins. The pumps that needed to power this kind of loop should have high flow rates but also good head pressure. Furthermore the inlet of the blocks should be a bit restrictive to create a jet pressure and the outlets should be as large as posible. With that being said small bore setups do very well with multiple components and smaller flows, but they reqire a high head pressure pump (as stated above) and I speculate that they hit a wall when cooling very hot components such as pelts sooner than larger bore setups. IMHO 1/2 inch setups dont have too look ugly at all, if the builder takes good care of his build the larger bore setup[ will look realy good. I have seen both small and large bore setups look extremely bad and both look extremly good. I also dont mind the loarger and harder tubing at all as I dip the tubes in boiling water for a minute to sofen it up and give it shape, I also like the durability of a larger tube, its harder to puncture and holds its own shape after its been cooled.
Both can give great performance. A good small bore (like german 8/6mm not 3/8"ID) system will generally cost more, but also tends to use much quieter parts and look nicer, not to mention is much easier to route. If you've seen FrozenFire, I have two 6800GTs (@Ultra), a 3000+ (@~2.4GHz) and a toasty NF4 SLI chipset all in one watercooling loop using 6mm ID (~1/4") tubing. It's pretty quiet and performance is quite good, not to mention looks great. It was very easy to set up as far as the actual cooling bit goes (plugging in the tubing, filling, etc) which is quite the opposite of the experiences I've had with large bore (I've never failed to spill water all over everything trying to fill a 3/8" or larger setup, and it's not carelessness), nor have I ever gotten a system to bleed well. If you're looking to do SLI watercooled, you either need to use small-bore setups or do something like GPU1->CPU->GPU2 in order to not get kinking. Or get a block built especially for an SLI setup. Of course, you really do have the potential for better temps with big-bore. It's just a fact that if you have two identical loops except that one has higher flow, the higher flow one will get potentially better temps. Keeping that in mind, big-bore and small-bore blocks are designed in very different ways, so there's no way to compare directly. A Dangerden block in a low-flow system will perform rather poorly (especially the maze designs), whereas putting a Cuplex Pro in a 1/2" system (if you can do that at all, and you can't without adaptors or modifying the top) will slow down flow faster than you can imagine. So either can do very well, but we're past the days where blocks absoluely relied on high flow to work. If you ask me, it really depends on a whole host of things, the top two being your funding available and personal preference.
So Firehed, what's the difference between a Danger Den Maze 3 and a Cuplex 1.3? They both have a very similar maze pattern, yet one is made for "high flow" and the other is supposedly for "low flow". Cathar's Cascade and Storm are very similar to Alphacool's NexXxos XP, and they all have one thing in common - they perform best with a high flow pump (well, higher than the flow an Eheim 1046 based pump can deliver, but it's not like Alphacool sells it with a 1046). Many of the so called "low flow" setups are nothing more than high-flowing parts with 8mm ID tubing. That's how Alphacool has great performance with the smaller bore parts. Check out this kit from a company (Alphacool again) that would be branded low flow simply because it is German: http://www.alphacool.de/perl/shop.p...menu_id=2&prod_id=100&art_kz=102&art_id=10204 Check out the parts: 1 Black Ice Xtreme 1 Alphacool AP900 (900 litres an hour! The Laing DDC only has 420 litres an hour, and it's sold as a "high flow" pump...) 1 NexXxos XP 8/10 tubing and more This will perform really well, compared to a larger bored system. The reason is because the only difference between it and the larger bore system is the tubing (it's a high flow system with small tubing). A lot of people that do buy the NexXxos XP do plug it into a large bore system, and it works really well that way. The Cuplex Pro will benefit more from a bigger pump than it will from the Aquastream, in fact, Aqua Computer has reccomended the Eheim 1048 for it too. Some people just prefer the smaller tubing, and feel that it is adequate for them, and there's no need for anything larger, and of course, some feel the opposite and, others are in the middle.
for the BIG BORE tubing... i like it personally i would suggest you to stay with 1/2" minimum ID only because of their performance, low back pressure hence less noise ans stress on the pump. Though 1/2 helps if you're using a decent pump with good flow/pressure characteristics, otherwise because of the increased tubing area of the big bore tubes the head pressure will drop a little, but as long as you're using short tubes around the waterblocks it should not affect that much the performance . I had the asetek kit few years back and these had like, 6.5mm ID which was totally pathetic. Converting the whole system to 1/2" ID the system performed extremely well with all 3 original asetek blocks on it and dual rad Temps got better overall and noise almost dissapeared from the pump. 1/2" for teh win
didn't quite got your question m8, but... i changed the barbs basically to 1/2" for all components, blocks/res/pump/rad Changes that i noticed are as i said, better performance overall (temp wise and noise) if that's what u meant.
The Cuplex does benefit more from high flow, but can still work well with lower flow. It's much less restrictive than any other Aqua Computer CPU waterblock so flow isn't reduced nearly as much as by, say, a Cuplex Pro. The DDC by actual flow rate would often be considered low flow. However it has a massive amount of head so it's good for very restrictive blocks as it can keep a lot of pressure. You're really quite right, it all does come back to preference. As I've said many times in the past, if you have two identical loops except for flow, the higher flow one will win. It's just how thermodynamics work. However compare a black ice series rad to an Airplex Evo series. Yes, you can use either perfectly fine in small-bore systems. However you'll restrict the crap out of a large-bore system using an APE rad. Now I've never seen them tested in near-identical situations so I can't say, but I'd think the APE would perform better as it's like fifteen passes versus two. Any large-bore radiator will be fine in a small-bore system. Many pumps will be fine, although some will have problems with a restricted inlet and many are too loud for small-bore users' tastes. However if you have a block that relies on high flow, you'll get poor performance using a low-flow pump. And on the other side, using a very restrictive block in a 1/2" line restricts it so much that any potential flow you could have over using something like 8/10 tubing is lost, so big tubing just makes it harder to manage. And Byron, I think she was asking if you've been able to change any components since converting it to 1/2". Upgrading is a huge PITA with big bore setups relative to any pushfit setup, ask anyone who's tried both. They both have plusses and minuses. People tend to get one idea stuck in their head that it's better no matter what. Try even thinking about anything less than 1/2" at procooling (and yes, 3/8" is just a more managable large-bore system) and you'll just about get lynched. I definately prefer the smaller stuff but I won't try and cover the fact that a high-flow system tends to have more potential. But IMO they're usually very ugly, always hard to deal with, very hard to set up, etc. See: try making a cpu->gpu1->gpu2->nb bend using 1/2" tubing on an A8N-SLI. It's just impossible. In fact it's near-impossible with 8/10 tubing too, and even tricky with 6/8, but it can be done. As modsquad put it once, we're all watercooling for show, so lets use the stuff that looks best (or something to that extent). And it makes sense, if you wanted crazy performance, you'd invest in phase change.
Aye, I fully agree with your words Firehed. @Top Nurse & Firehed, yes i changed any component i like after the conversion without any problems (used LRWW waterblock on same loop etc.). It wasn't a PITA tbh, but fun for me i would say Yes indeed most people watercool for the bling factor and show off. Personally i'm totally into the other side though, would sacrifice anything for max performance etc. because i want to squeeze every last Hz out of my components with water-cooling. Indeed though 3/8" is much better or even smaller to use in multiple components (dual vga's etc. etc.) or even smaller tubing. From the other hand, in some cases i believe that you can use thick tubing in some setups if you re-arrange or use other/different waterblocks.
Thanks for all the replies everyone. After doing some reading on this subject, I'm surprised this thread has remained as civil as it has. Some people out there get down right nasty arguing this subject. What I've come up with (involved a lot of reading and thinking) is that using a larger bore never decreases performance. Some blocks may be optimized for a low flow and may work just as well in some cases as a setup using large bore parts. Also, low flow parts may not beneft much from higher flow rates, but this never decreases their effectiveness, nor does using larger tubing over small tubing. Sooo... It makes no sense to me to switch to a smaller bore and potentialy sacrifice performance, regardless of what equipment I use. Especially since I already have a large bore setup and this size of tubing is more convenient to use for me. Well parts and assembly wise anyway, maybe not routing. Ultimately I prefer to use 1/2" copper pipe for as much of the plumbing as I can, and use the flexible stuff to allow blocks to sit level and allow them to move out of the way when I remove some equipment. I know it's just personal preference but I find the copper pipe easier to route, takes up less space, and looks more organized. I'll just have to be mindfull of where I put the inputs and outputs of the blocks I build in the future to make routing with large tubing easier. Also I'll have to look at making some changes to my current setup to make the plumbing a little more neat looking, I think It'll make adding adition blocks in the future easier.
