I tried experimenting with the H61+G530 build, which was recently blessed with a new Hyper TX3 HSF. Since the CPU is frugal, and the heatsink is quite big, I thought this would be a good candidate for trying to cool it passively.

The computer was still running after 1 hour, of Prime95 and rthdribl, but the temperature reached 95 C, so I stopped the experiment.

I know that tight fins are not supposed to be optimal for fanless coolers, but it's strange that the heatsink was so cool to touch, even when the CPU was scorching hot. I would imagine the heatpipes would help distribute the heat from the socket to the fins? Could it be the cooling paste that's applied inadequately, or would it help with the heatsink oriented the other way around?

Picture of the setup
Windows screenshot of temperatures

Whether the heatsink is mounted correctly or whether its a TIM issue can be answered by looking at it when idle, and to see how fast the CPU temp drops after you stop the benchmarks.

Also, did you have the case side off whilst testing, or did you only take it off for the picture.?

As far as the heatsink orientation is concerned, I would guess there would be a 5C drop in load temps (NOTE: that is a guess), but that heatsink really has to dense a fin stack, and there is barely any airflow passing the heatsink - I am not at all surprised that the CPU is that hot, as the heat accumilates, if anything I am surprised it stopped at 95C, and consider what would happen if the ambient temperature went up by just 5C, your PC would crash regulary or something would break.

You might be best off either adding a fan to the CPU (in its current orientation) + a cardboard duct tube to the 120mm fan hole at the back of the case. Or add a case fan at the back + a duct to the heatsink. The first option would be quieter as the fan would be further away from the back of the case.

FYI, the thinner the fan the lower pressure, the more densely packed the fins the more resistance. A 500rpm SlipStream on the heatsink, with a duct would likely keep the CPU within a sensible range, whilst the PSU fan would extract the rest of the heat from the system.


Andy

Hi, I would think at 95°C you've hit the CPU's throttling temperature, my i7's is about there...
That is the CPU does less and less work until the temp stabilises at that point, I think it does this by dropping the multiplier or adding "blank" cycles, ie cycles when it does no processing and therefore generates a lot less heat. You can check this with TMonitor.

I've used a Hyper TX3 a number of times as a good performance, low cost heatsink. Pair it with an Arctic Cooling F9 PWM fan, which is also dirt cheap, and it's great! The fan will idle down to ~500rpm and the examples I've used are very smooth and super quiet at that level, while providing enough cooling for low and mid range CPUs without any need to increase fan speed much. In fact I found that with a pair of F9 PWMs a Hyper TX3 could cool my i7 2600k (at stock), the screen shot I have shows 67°C core temp with the fans at a very quiet 700rpm.

I wouldn't use it passive, a very quiet fan is all you need and will keep the temps easily in check at 400~700rpm. Possibly mounted on back of the heatsink to blow hot air straight out the back of the case.

Regards, Seb