Ok.. was thinking about my temps today... and why they don't seem very low if I go over 1.5v. Don't ask me why I tried this, but I disconnected the fans on the rad.. and guess what. It makes no difference at all.. nothing. WHy should this be? With no fans, the temps are exactly the same. Anyone help?
A radiator doesn't entirely need fans, but I'm surprised that they don't make a difference. Maybe your case pressure's acting to create an airflow through it?
That might lower things a bit, but I'm still quite amazed that it works without fans. Stick the panels back on and see if it goes up.
Is your radiator horizontal? It does this on mine too... the radiator does exactly as it's named (simply, it 'radiates' heat) and thus with or without fans, the radiator is transferring heat from the water inside it to the surrounding air around the radiator. With or without fans, heat transfer is occuring. Fans help this by removing the the warm air away from the radiator. It is a common miscomception that the fans are used to 'cool' the radiator and thus the cpu temp... that is false. What in-fact is occuring is that the fans are used to promote a larger temperature differential between the air and the radiator and thus promote more efficient heat transfer. If you computer is idle, your CPU is thus transferring X amount of heat into the water cooling system... thus the radiator needs to transfer X amount back into the atmosphere to keep the termperature at equilibrium. Radiators can do that without the help of any fans. But when you load the CPU for a prolonged amount of time, you will find that teh radiator can no longer transfer the same amount of heat energy to the atmosphere as the immediate temperature of the air around the radiator has increased... thus a fan is needed to move it and replace it will cooler air.
How long did you run with no active airflow and do you have a reservoir? My rez/rad combo hold enough coolant to run nearly an hour (at non-stress levels) before the reported temp rises much. What I find strange is that the reverse apparently isn't true. Turn on the fans and within a few minutes temps begin to drop. I'd have expected a more 1:1 relationship, but given my totally inadequate temp monitoring capabilities I just consider this an oddity and not real data. My rad sits vertically, btw.
Ok... yep.. it's horizontal. At idle... it makes absolutely no difference whatsoever. I've been running a prime 95 test for around 30 minutes now, with the CPU at 100%... it's still running as I type this, so the system is getting a good kicking.. with no fans, the temps rose to 60 degrees, which is the highest I've ever seen it... with fans on, it slowly came back down to 57 or so. Still... hardly a great difference considering there are three 120mm fans on that rad. I was hoping they'd be more efficient than that. Yes... I have a reservoir... quite large one. Click on the project link in my sig to see the system in question.
I had similar problems, I was idling at around 45°C with the central heating on. My radiator is vertical at the front of the case. I'd reseat the block with some fresh paste and tighten the screws down a bit more
It's fine. It's seated properly, with a nice, even coating of arctic silver ceramique paste. Everything is tightened properly, and evenly. I wonder if there's an airlock in the rad?
Another answer, albeit a strange one, is that it is at max efficiency. Look at case ambients in the area, and see if they drop with the fans on...
have you gota shroud on the radiator? if not the air is going threw the fan but wants to escape quickly. as the radiator is the way it will take a different route not going threw the radiator. another thing is ur fans are turning to slow, below optium rpm to generate an air flow.
I have no shroud, but the fans are fully sealed with silicon to form a complete gasket.. no air escapes. All three papst are getting 12v. Still a mystery this one.
nah... natural convection is quite powerful... especially in that rad configuration... there is lots of disspation area and thermo physically seen it's perfect, since hot air as well known wants to go up and now there is nothing stopping it from doing that
Over what timescales are we talking? When testing passive running, you need constant 100% load over a period of 12hrs or so for a useable equilibrium to be reached. With fans running, you need to give it at least an hour before their effects will be majorly noticeable. It's a lot harder to cool hotter water down than not-so-hot water if ya get my drift. So, 60 passive, down to 57... leave it running at the same load overnight, and see what temp has dropped to next day. Not forgetting to note any differences in ambient temps. Difference in water temps between rad inlet and outlet is only 0.5 deg (ish)... so it tends to take a while for any change in airflow characteristics on the rad to fully come into effect. Start a rig with ambient temp water and fans at 7v. Time how long it takes to reach temp X. Now do the same test but put 60 deg C water in the loop. It'll take noticeably longer for the hotter water to get to X than it did the colder.
I must admit, I only watched it for a short while. However, in a car, when the radiator fans kick in, the reaction is almost instant... I was expecting teh same thing. The temps are fine I suppose, 'cos I am running quite a high Vcore to get this chip stable. The GPU is standard in terms fo voltage, and that idles at 32 and never goes above 45 and that's massively overclocked, so all in all I'm happy. Was just expecting to see the temps go through teh roof when teh fans went off, but nothing seemed to happen. I guess I can get teh fans on a control bus now, and practically turn them off when just surfing... that should make things nice and quiet
a car is a bit different... larger radiator though larger heat source... and the movement of the car works as the fan so tha fan is needed only when the temps reach a certain point
