MessyPC: A Corsair Obsidian 250D fully water cooled build

[foop]

I decided that I needed a small format PC to go in what we resignedly call "the Messy Room". It's one of the few rooms in the house in which you can't hear the local drunk teenagers charging up and down the street outside on a Friday and Saturday night. It's also got a nice sofa and a large HD TV on the wall, and is ideal for relaxed gaming.

I'm a very impatient PC builder, so this was designed, ordered and thrown together in about three days (hooray for OcUK, and Saturday delivery). There's a moral to this story too...

Don't rush a watercooled build, especially in a small case

The design phase

After much measuring of shelves and cubbyholes in the messy room, I had an idea of what sort of size of case I could work with. Of course, I also had to get one that would fit watercooling kit. The BitFenix Prodigy is always an option, but I looked at some builds and decided that I didn't like it. The Corsair Carbide Air 240 looks great (if a little large). Then I read some build logs where I discovered that because of the two compartment design there's not much space between the top of the GPU and the windowed side panel. If you've got a cooler with the ports on top fitted to your GPU it's touch and go whether you'll be able to get the panel on without the block touching the acrylic. So, it seemed like the 250D was the best bet.

Here's what I ordered:

YOUR BASKET
1 x EVGA GeForce GTX 970 Superclock 4096MB GDDR5 PCI-Express Graphics Card (04G-P4-1972-KR) £299.99
1 x Intel Core i7-4790K 4.00GHz (Devil's Canyon) Socket LGA1150 Processor - Retail £289.99
1 x Samsung 500GB 850 EVO SSD 2.5" SATA 6Gbps 32 Layer 3D V-NAND Solid State Drive (MZ-75E500B/EU) £149.99
1 x Asus Z97I-Plus Intel Z97 (Socket 1150) DDR3 Mini ITX Motherboard £109.99
1 x XSPC DDC Single Bay Reservoir/Pump Combo £89.99
1 x GeIL Black Dragon 16GB (2x8GB) DDR3 PC3-12800C11 1600MHz Dual Channel Kit (GD316GB1600C11DC) **OcUK Exclusive** £86.99
1 x Microsoft Windows 8.1 64-Bit DVD - OEM (WN7-00614) £79.99
1 x EK Water Blocks EK-FC970 GTX - Nickel £79.99
1 x Corsair Obsidian Series 250D Mini ITX Compact Gaming Case - Black (CC-9011047-WW) £75.95
2 x EK Water Blocks EK-Supremacy EVO - Nickel (Original CSQ) £52.99 (£105.98)
1 x Samsung 120GB 850 EVO SSD 2.5" SATA 6Gbps 32 Layer 3D V-NAND Solid State Drive (MZ-75E120B/EU £49.99
1 x EK Water Blocks EK-CoolStream PE 240 (Dual) £39.95
1 x Monsoon 13/10mm (ID 3/8 OD 1/2) Free Center Compression Fitting Six Pack - Black Chrome £24.95
1 x EK Water Blocks EK-FC970 GTX Backplate - Black £18.98
1 x Mayhems Pastel - UV Lime Yellow Coolant 1L £14.99
2 x Scythe Slip Stream SLIM 1600RPM Fan - 120mm £8.99 (£17.98)
1 x Primochill Primoflex Advanced Tubing 13/10 - Clear £5.99
Total : £1,556.68 (includes shipping : £12.50 Ex.VAT).



From reading around, I discovered that the main thing to take account of when putting cooling in the 250D is that you only have 55mm to fit the side radiator and fans in. This either means a slim radiator and 25mm fans, or a normal (not fat) radiator and slim fans. After much faffing about I decided it would be easier to go with slim fans rather than a slim rad. My choice was helped by not being able to find slim rads in stock anywhere on the web.

I was also planning to put a single 120mm XSPC rad and 25mm fan in the front of the case, but as you will see, this was not to be.

 

[foop]

Things arrive, and get tested



Yay! Parcels!



Loads of goodies. You can just see my son snaffling the Haribo.

Time to get stuff out and test it before I start voiding the warranty on things.



So this is the bare bones of the PC.



The Asus motherboard is actually quite nice, despite being relatively cheap and cheerful for its feature set. There's no horrible features to work around.



It lives! I installed Windows 8.1 and gave it a quick test with FurMark and Prime95 to see how air cooling fared. I learnt two things: the stock Intel cooler is quite ******, and I really hate Windows 8. In contrast to the Intel heat situation the EVGA 970 is very quiet under load and doesn't heat up too much.



(Apologies for the potato quality)

 

[foop]

Squeezing things into the case

Okay, time to have a look at the case.



It's not the smallest mini-ITX case in the world, but that does mean we can fit a reasonable sized radiator in it. Hopefully. Sort of.



Lots of ventilation. The mesh over the vents is held on by magnets. It's a nice idea, but it's difficult to stop it being baggy.



That's what I like to see - everything comes off very easily. Almost everything (bar the 5.25" bay) is held on by thumbscrews. The HD bay is next to the PSU bay, and has slide out cradles for two 2.5" and two 3.5" drives.



Everything's nicely ventilated. It would work very well with an air-cooled build, and has a 120mm and 140mm fan fitted as standard, with space for two 80mm fans at the back and another 120mm at the side.



Completely stripped down. The case fittings come in a box which fits in one of the HD cradles (complete with holes in the side for the pins to engage in). Nice touch.



So I went for an EKWB 240mm radiator (about 37mm thick) and two slim Scythe fans (12mm). This fits nicely in the 55m we have to play with for a radiator. It will, however, bite me later.



Right about now, in fact. The ports on the rad clash with the USB riser on the back panel of the mobo. A rad with more central ports would have been better, but might have been too thick. A cross-flow rad would also have been good, but I couldn't find one the right thickness with the ports in the right place. And I'm impatient.



Sigh.

Ok, time to turn the rad around.



Ok, the other way round the port *just* fits under the 5.25" bay cage. But this scotches the idea of putting a single 120mm rad in the front of the case because there's no way to get the tubing from the port back into the case without hitting the rad/fan in the front.



And here's the next problem. The screws that come with the EKWB rad are for a 25mm fan. If you use them with a smaller fan they'll pierce the water channels.

So, I could source some M3 bolts of the right length. See my previous comment about being impatient. Fortunately, I have a great box of fittings from last year's Enthoo Primo build (Yay Phanteks! <3). They fit, but I can't get them into the fan without cutting off the corners.

It's a kludge, but it works.



Time to apply water blocks to everything.









Right. Now it's time to build the loop.

 

[foop]

Building the loop

Does the rad really fit this way round?



Yes, just. Everything else works really simply, helped by the compact arrangement. None of the pipework really has to bend too sharply and there's enough slack to let the reservoir/pump combo slide out for filling.

I'm glad I didn't choose this build to try acrylic pipework though.



And now to fill and test the loop. Apologies for the coolant. I like horrible cliched colours.

Oh, and I had some premade braided cables lying around which made the cabling look a bit neater. It's a rat's nest in front of the PSU though.





After running the loop for a while without any power to the components, I tried booting and running some stress tests. FurMark gave a steady GPU temp of 49 degrees after an hour or so. Prime95 blend sat around 50 degrees on all cores after everything settled down. Better than the approaching 100 it got with the stock cooler.

All fine and dandy, right? Not quite.

 

[foop]

Problems, Problems

So, what went wrong? The HSPC bay res/pump combo mostly.



Problem one: bubbles. Lots of small bubbles. They just won't go away. I've run it for hours. I've tilted it every which way. I've let it rest to get the air out, then tilted it all around the place to get the bubbles to the reservoir. I've topped it up, removed coolant, topped it up again.

I think the problem is that although the reservoir has a baffle built in that supposed to stop bubbles getting into the pump, it doesn't work. It's a tiny reservoir and any bubbles that are formed just go round and round the loop forever.

Problem two: noise. The pump is awful. It's just a DDC pump but I've never heard anything so loud. It's worse than a bad fan, a horrible mid-pitch whine. Whether it's noisy because of the air in the coolant, or whether its always like this I don't know. Frankly, I don't care. I hate it.

What to do?

I'm thinking of getting a separate pump and stashing it somewhere in the front of the case. I still like the idea of having a bay reservoir, but hopefully a bigger one won't have so much of a problem with bubbles. The alternative is going with a small traditional pump/res combo.

I just have to fit it somewhere in the cable mess.



Help meeeeee...

Anyone have experience of the XSPC bay res/pump combo? Any great suggestions as to how to improve the loop with a separate pump and bay res or pump/res combo?

 

[Telecaster]

Looks like you've got your work cut out for you there! Props for having a go.

Are those fans not a bit noisy, or is it a case of not being able to hear them over the pump?

 

[kaku]

That does looks like a challenge.

Maybe some angle fittings could help you on the radiator, at the expensive of using more horizontal clearance. You should find that the tiny bubbles eventually join together to make bigger ones that you can bleed out. I think it took almost a month for all of the microbubbles to dissipate in my system.

Is the pump PWM controlled or is it running full whack all the time?

 

[foop]

Are those fans not a bit noisy, or is it a case of not being able to hear them over the pump?

They're surprisingly quiet. Not as good as the NB-eLoops I've got in my main machine, but not that bad. I was planning to run them a little slower but I don't think I'll need to.

And, as you say, I can't hear them over the pump.

 

[foop]

That does looks like a challenge.

Maybe some angle fittings could help you on the radiator, at the expensive of using more horizontal clearance. You should find that the tiny bubbles eventually join together to make bigger ones that you can bleed out. I think it took almost a month for all of the microbubbles to dissipate in my system.

Is the pump PWM controlled or is it running full whack all the time?

I had some angle fittings knocking about but they didn't really help - there's still not quite enough clearance between the fitting and the front 120mm fan or radiator.

As you guessed, part of the problem is that the pump is running at full speed. That isn't helping the bubble problem at all, and it may be the bubbles that are causing most of the noise.

I don't have any way of controlling it, and I think the 18W it requires would kill any fan controller I have. I may try getting the calculator out and wiring up a molex extension cable with the appropriate resistors (if I can find them).

 

[dacads]

Well I don't know anything about WC so can't help with that but I want to say the name "MessyPC" is definitely suitable

 

[grim.]

Problems, Problems
Anyone have experience of the XSPC bay res/pump combo? Any great suggestions as to how to improve the loop with a separate pump and bay res or pump/res combo?

I built a water loop for a friend last year using the same pump and res and it too was really loud. Even when slowed right down it was still a noisy pump. So much so we've been meaning to change it for a D5 and separate bay reservoir. That doesn't look like an option for you unless you get really creative with the tubing and space.

I've been using nothing but the D5's since I had a couple of ddc's fail on me. Never had a ddc as loud as the one in my friends res combo though

 

[foop]

I managed to make some progress. I rewired a molex extension cable to supply 7V to the pump. This made the world of difference - the air bubble problem is almost eliminated and the pump is almost silent. CPU and GPU temperatures are pretty much unaffected under load too.

The only drawback is that the pump tachometer now reads zero all the time. I assume there's a voltage or speed threshold at which it starts working. It's not the end of the world, but I'd like some indication that the pump is actually operating.

What I'd like to do is up the voltage a little, but that's more complicated than a simple molex rewire. A fan controller would be useful, but they're almost all designed to fit in the 5.25" bay which is occupied by my res/pump combo. There are a couple of non-bay controllers that could handle the 18W the pump needs, but they're all out of stock at OcUK. Grrr.