For the past several months I've been using a Scythe Mugen Max heatsink on one of my Core i7 5960X Haswell-E systems. That heatsink has been working out great, but the only problem is that it's too big -- particularly if trying to fit it in a 4U chassis. In needing to cool this 140 Watt CPU while moving the system into a 4U rackmount chassis, I ended up trying out the much cheaper and smaller Freezer i11 from Arctic Cooling.
When deciding to move this open-air system into a 4U chassis in a new rack in the office, I was searching for a smaller heatsink that could fit within this cheap 4U chassis while still sufficiently cool the processor and not cost too much. The Freezer i11 ended up fitting those requirements with the cooler being 130mm tall, its rated for a maximum cooling capacity of 150 Watts, and costs just over $20. I was a bit hesitant at first though with the i11 having a rated maximum cooling capacity of 150 Watts while the recommended max TDP for the processors to cool is 130 Watts: the i7-5960X has a 140 Watt TDP.
So while it's not too often that I write reviews on any cooling products these days on Phoronix, I just wanted to mention the Freezer i11 as it did end up being able to effectively cool the Core i7 5960X Haswell-E while fitting within a 4U chassis. I have used the Freezer i11 in other rackmount cases in the server room, thanks to its relatively low-cost compared to some of the higher-end after-market coolers, but never with a CPU having a TDP over 100 Watts.
The Freezer i11 has three heatpipes, 45 luminum fins, 92mm PWN fan rated for up to 74 CFM airflow, and supports all modern Intel CPU sockets.