Really dire temps for new loop - advice...

Michaeljcox24

New member
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So this is the loop I was on about building mid last week. The build went well in general. There were a couple of bollocks dropped, but it was my first ever loop and cosmetically, a lot of people have said it's pretty good for a first time effort. I did manage to spill coolant in the PSU, which after a couple of days in the airing cupboard was ok, and at one point, the thermal cap came off one of the cards, but again, with a bit of MX-4 I re applied to the gpu itself, re covered, and things went ok.

However, looks are not everything....

The cards idle at 30 and 31, and the cpu idles at 30 - 35. Under load though, is a different kettle of fish. The top card slowly goes up to 75 ish, and hovers around there with the bottom card sitting around 60 - 65.

I've tried tipping the rig left and right, and back and forward, but no bubbles appear anywhere. It's been like it for 3 days now, but I can't seem to resolve the issue. I've got the pump speed on 5, and the fans on full blast. So gents.....

- Do you think investing in a stand alone rad like a RX240, and sitting it next to the rig instead of the fixed 140 on the side, temps would improve? I've got tomorrow off to shop about but it seems like a hell of a lot of degrees to pull back. I don't want to be in the situation where I invest 100 odd quid and it pulls back 2C. I can sit it round the back of the rig and run the fan leads in through the back of the rig in an expansion slot.

- Would changing that prolimatech fan on the back for a GT fan improve things much?

- Does the parallel link look right between the cards?

- Are there any other known ways of faulting finding loops like this. This is my first ever one and I'm pretty much open to being called noob of the year if it means resolving the issue.
 
Problem didn't go away iirc when you switched to serial? (from ocuk forums)?

Just checking:

-the pump is fed from the reservoir by gravity?
- the rads are bled of any airlock?
 
I had exactly the same temps when I switched to serial last time, if anything, they were worse. The thing is though, during that part of the build, the thermal cap came loose on one of the cards, which threw me off a bit, and might not have caused the problem to get worse.

-the pump is fed from the reservoir by gravity?
Yes, It's Dual Bay D5 pump sitting at the top of the rig, one bay down from the top of the case.

- the rads are bled of any airlock?
Yes, I've had it running for four days now and there aint a single air bubble in it.

I'm trying Toms idea today anyhow. Willing to try anything tbh. Will post back when I've got some results.
 
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ok, loop is back in serial again, and I've put some fans on the top of the 360 rad, in pull, to improve air flow over the fins. Weirdly, they don't fit properly, either fan is too small or rad is too big. Either way, I can only screw one screw in per fan.

Temps now, rise up to 70, instead of 76 / 77, which is an improvement. Temps on the bottom card are still 10C lower though.

I was thinking about it over a beer last night (when lets be honest, we can be at our most thoughtful, and I think that the L Bend under the bottom card is causing a flow problem. I reckon coolant is flying through the top card, and then backing up a bit when it reaches the alphacool L Bend because of the right angle. The coolant might be staying in the bottom card for longer because of this.

I don't know. But got to eliminate it as a potential cause.

So I'm gonna change that today, and put a normal barb on. Need some more hose though, so will report back later because I aint got any in the house.
 
2x EX rads trying to cool 3 blocks. Not sure if you could squeeze a thicker top rad in without encroaching on the rear rad.
Hmmmm. I would ditch the hard drive cage and put a rx240 in the bottom.
GT fans ftw by the way. Great units.
 
ok, loop is back in serial again, and I've put some fans on the top of the 360 rad, in pull, to improve air flow over the fins. Weirdly, they don't fit properly, either fan is too small or rad is too big. Either way, I can only screw one screw in per fan.

Temps now, rise up to 70, instead of 76 / 77, which is an improvement. Temps on the bottom card are still 10C lower though.

I was thinking about it over a beer last night (when lets be honest, we can be at our most thoughtful, and I think that the L Bend under the bottom card is causing a flow problem. I reckon coolant is flying through the top card, and then backing up a bit when it reaches the alphacool L Bend because of the right angle. The coolant might be staying in the bottom card for longer because of this.

I don't know. But got to eliminate it as a potential cause.

So I'm gonna change that today, and put a normal barb on. Need some more hose though, so will report back later because I aint got any in the house.

Flow stays constant thru the loop,you cannot pressurize water so there is no backing up. The IHS that fell off,did you redo the paste? or add paste if it was soldered? Im never took the time to find out about NV delidding...
Maybe worth doing a remount.
 
I re did the paste on both, and did a re mount of the block. Before that, it was going up to something saft like 88 after a couple of mins. I can't see how I can improve on the job I already did.

I think that's definitely the problem that's causing the 10 degree or so difference in the cards at the moment though, I agree with you.

I've changed the angle fitting to a more curved one, and put some pull fans in the top of the case, and now the temps hover around 68 and 62 on load . I honestly think that's as low as I'm going to get without investing in a new rad, and sitting it outside the case. I can live with those temps, as long as the rig is quiet. The cards are already overclocked, and I'm at the 'point of diminishing return' because to get up to 900 it needs 1.1. It really isn't worth it for an extra 20 or so Mhz.
 
You dont need a new rad you need to fix the water flow out properly, 1 in 1 out.

Beyond that if they are still THAT hot they are faulty.

Do the flow first.
 
I'd probably expect temps like considering the rad space you have.
EX360 and a 140mm rad for a CPU plus 2 GPUs?

I'd be thinking you're pretty lucky to stay below 70.
What temp is the CPU?
 
I'd probably expect temps like considering the rad space you have.
EX360 and a 140mm rad for a CPU plus 2 GPUs?

I'd be thinking you're pretty lucky to stay below 70.
What temp is the CPU?

This is what has pissed me off a bit to be honest. I asked the pre sales peeps at the online retailer if the kit they sold (and I bought) was enough for two gpu's and a chip. This was my first ever loop, and all they said was I needed 120mm square of rad space per heat source. The fact that I was throwing in a 140mm was a 'bonus' and meant I would have got excellent temps.

Technically what they said was true I guess, just there varying degrees of 'heat source', and the ones I had were too hot for the thinness of the rad in the kit.

I can't get any better with in / out and flow now, and there are definitely no hum-dinger bubbles in the loop, so it can only be rad space, surely? Or, like TTL said, really bad contact on both blocks.

I was going to get an RX240 today, and run it outside of the case, sitting on the desk, instead of the EX140, which seems to be doing jack. People I've spoken to seem to think trying to push coolant through 2 360's would be too much for the pump, but a 240 would work. Special Tech have sold out though, so I'm gonna have to wait. I did see the AX240 and a nice stand, but it looked too thin for what I need.

When I had a game on today, cpu was maxing at 54.
 
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Rads aren't restrictive at all really.

What pump are you using? A D5?

Your temps are high in terms of watercooling, but not so high it will damage the cards. 120mm per heat source is a little edgey, and doesn't account for overclocks at all.
Here, we say more CPU, 240mm (preferably 60mm), CPU and GPU, 60mm thick 360, CPU and 2 GPUs, 60mm 360m plus a 240 (again, preferable 60mm thick).
That's mainly so we can have the fans and pump on a nice low speed and still get great temps.

What case do you have?
 
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Case is a HAF-X. I really don't think I can fix an RX360 in the top though. There's about 2.5cm clearance till I hit the CPU power in socket and there's a blue heat sink right at the top of the board. It would be very, very tight.

EDIT: Just measured up. I have absolute max of around 12mm free at the top, and according to the specs, RX360 is 63mm thick, EX360 is 35.5

So I would need 27mm. Definitely, would not fit.
 
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Forgive me if i missed it, but what temps you getting on the cpu?

Is the fluid warm? are the backs of the cards hot?

I have 2 580's on a 280 rad and they absolute max out at 49 and that's with me being lazy and not allowing cool air near it, previously one of my older 580's was topping out around 90 sent it back got a new one, temps are almost identicle now at around 45 on load

I've popped the top off a 280 before and just super-cleaned it, removed excess cement so it seated properly re-timmed (sparingly) and it was absolutely fine. (this was a while back)

Quick silly question, is the cpu block setup the right way round for the flow?

how deep into the cards are the fittings? do they require spacers? (could be over-restricting the flow)

How does the water flow react in the res when you turn the pump speed up and down? any difference?
 
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