If most custom wc loops are built inadequately, it's surely because most people don't know any better. 😉 Even the more intellectually gifted among us balk in the face of the idea of putting water inside our computer, much less designing & building it ourselves. lol

I like where this thread is headed, though. I am one of the many morons who knows very little about custom watercooling, but it's on my to-do list for next year, which means I'm hungry for info. Do go on about this flow rate calculation/design optimization..... 🙂

Yer custom loops are pretty much the same as car modders - The main goal in most loops is'bling factor'

I spent loads on all this fancy looking cooling equipment only to realise that it performs 'slightly' better than a H100..

Temps were always high with my chip so in the end i got a chiller. It doesnt look pretty but it cools properly when I need it too.

Most custom loops will be doing a pretty good job in my opinion unless the bling factor has so taken over that multiple blocks are giving terrible flow rates. Seen quite a lot of this type of loop because those same people like posting up pictures...and hey why not. But most people run pretty basic loops and the majority of them will function well and cool much better than a H100 (if you want to talk about inadequate you could start there IMO).

The figure of 3GPM I don't know where that comes from. Greater flow means greater turbulent flow and greater heat exchange in the lofty theoretical world of fluid mechanics. Back on Earth and keeping your flow rate above 1GPM and your loop will work well...

So that loop running a D5 will need, to maintain at least 1GPM, a pressure drop over the 2 360s and the 3 blocks of less than the (from that graph posted) 4.54 PSI that the pump needs to deliver. Average 360 0.3psi drop, average CPU block 1.6psi drop, average GPU block 1.1psi drop. add those up and you find the loop will deliver 1GPM from one D5 no probs.

If he's got a decent top on the D5 a bit more...and if he's got paralell GPU blocks a bit more so say a perfect 1.3GPM.....good loop good cooling.


http://martinsliquidlab.org/pump-planning-guide/

Well, anyone can correct me if I'm wrong but there are two main concerns with the functionality of the design. The flow rate, and the temperature difference (Delta T).

I was using theoretical values and calculations for all of mine. Here is a pic of my old system.

As mention prior I went with the H100i because it did the same thing for my CPU and I didnt want to juice the living hell out of my GPU. The RAM was just pure bling bling but added more restriction.

Here is a website that I used that really helped with discovering values.
http://martinsliquidlab.org/pump-planning-guide/

My best advice, unless you are going to be some professional overclocker, just buy a closed loop.


P.S. I did juice the living hell out of my GPU with the cooler. I even used a modded version of Trixx to give it more voltage. I got my single card to score almost as much as my crossfire with a small OC on each.

I have been playing with PC's or at least processors since the mid 70's. Water cooling has had a huge growth spike in the last two years, but that interest was there twenty years ago. Before Swiftech or any of the current resellers were around. One of the top guys, from a theoretical perspective was a Aussie designer and the debate at that time was exactly the same as it seems it is now.

Bottom line is keep things simple, 90' angles are not good for flow rate, but flow rate is not as critical as most would imagine. Higher is not going to translate to better cooling in most cases. ZKa hints at it, and Arne states it. So if a loop is littered with 90' bends and Y splitters then yes flow will be a issue. Otherwise no.

Closed loops are no more or less efficient than the top Air coolers and I can personally vouch for this. H100 v my air coolers and I get the same OC with both, and a 2'c difference between them. With a Hex core the air cooler works better by the way. Saturation is what it is all about folks and the laws of thermodynamics. 🙂

Hartacus wrote:
I was using theoretical values and calculations for all of mine. Here is a pic of my old system.

Yeah, well, for me (personal thing...and maybe objectively too) that is too many separate blocks and the RAD you had in the roof looks thin and measly unless it's on the outside of the case....can't tell....and the pumps? can't see what they are but one strong pump with high flow pump top better than two weaker ones; pumps add heat to a loop too...(just saying that bit in general...like I say can't see if that was your case). But all in all, it would have done it's job as you yourself point out...the GPU OC was good....get that on a H100i :rolleyes:.

"Worth it" in degrees per dollar...probably not on the CPU but that is not the whole reason of watercooling...big fun element....bling etc. and if you cool GPUs these days it is definitely worth it. My Titans on air were great (since the cooler is a work of art) on full cover water blocks sublime....no comparison...

I think lots of people buy a case and then think about WCing it as an afterthought or next project and then compromises are made etc. that might mean the cooling, while it works OK, doesn't really beat out a closed loop cooler by much. nothing wrong with that but if you analyse it, cost effectiveness only, a custom loop might not look so rosy. Also doing it right is expensive so people budget maybe less than they should and further compromises are made but the expectations are still there of stellar cooling.

There is also a lot of bad advice out there. 95% of watercooling threads are filled with misunderstandings, or theory that doesn't translate to practice etc. so, easy to go wrong with your first loop....

Zka17 wrote:
He-he, for a while now I'm running my loops on very slow flow... getting much better temps than with fast flow...

Happy for you Z but that will be a peculiarity of your loop... in this universe faster flow means better cooling. Common sense....just blow on the back of your hand fast and slow...but this goes to show that there are plenty of variables that can upset the orthodoxy in practice and flow of air through RAD and flow of water through loop needs to be experimented with and the interaction of both together studied and optimized for "your system"..(I mean general your not yours Z...looks like you've done your homework).