Noctua NH-U12DO A3 for AMD Opteron workstations and Servers CPU Cooler

Pros: the best

Cons: These are the best cooler for G34 socket. I have installed 4 of them on a supermicro 4042G-72RF4 (4x16=64 cores, 256GB RAM, 24 TB Raid 6 SAS, linux debian) to run a well-known repository of materials properties. After a bunch of fan-de-supermicrization and fan-noctuization (with extra 500$), the computer got silent and can now sit on my office. Temperatures are 25C idle and 43-45 at max (128 threads on 64 cores, measured with lm-sensors). The 10 HDs are 35-38C depending on the temperature of the office. The master HD is a Samsung SSD, trim-ed with ext4.

Size: this cooler FITs the ANTEC titan case (the old repository with 24 cores on 2xG34), sold as 4U. The cooler does NOT fit the supermicro case as the heat pipes stick out of 4-5 millimeters (noctua should make them a little shorter, with 3-4 fins less). In my setup, the heatsink of the top CPU of the motherboard also requires cutting a part of the 4 fins, up to the heat pipes (be careful with them, they contain sodium vapors).
I ended up cutting a part of the removable panel in our shop and I consider bolting a discreet dark grill. Overall the machine needs to stay ON for 4/5 years, 24/365 so it needs to be solid-reliable. I keep a few fans for safety and I can change a defective fan without turning off the machine.

These noctua are the only solution. Despite what noctua says, the U9 heatsinks are too weak for 4 sockets motherboards inside a want-to-be silent-case. With the U12, you get no more than ~45C on your cores.
My opinion is that the perfect heat sink should be a slightly shorter version of the U12, since the fan can be adjusted up/down to accommodate RAM.

Anyway, if you want a solid and silent computer, if you want to avoid problems related to liquid cooling (e.g. leaks, evaporation, corrosion), these noctuas are pretty much the only solution.

good luck.

Other Thoughts: If you can, avoid PWM fans. They push less air unless you PWM them up.

Pros: This is an update to my previous review, noctua customer support was excellent and shipped out another fan no questions asked. They simply requested that I break off one of the fan blades on the borken fan and send them a picture (to avoid sending them the broken fan). With service like this I had to give them another egg.

Cons: Fan broke after 4ish months, but customer service was great!

Other Thoughts: I would reccomend this to others, and I would by the cooler again. In fact I will be ordering two more for a new GPU/CPU computing node for my home-build cluster.

Pros: I have two of these cooling the head node of my home-built mini-cluster (I do computational research), it keeps my 6128's nice and cool.

Cons: One of the very high priced 120mm fans broke after owning it for 6months (about 3 months of use).

Pros: The fans run very quietly with this. If you end up hooking it up to a source that doesn't offer PWM speed control, there are some connectors with in-line resistors that will lower the speed of the fan so you can run it more quietly.

I chose Noctua because of the great things I've read about them in computer magazines and also from using them in a build I did for my brother. I was impressed with how cool and quiet his air-cooled system was, so I decided to use Noctua for my server upgrade.

Everything is included, such as heatsink thermal compound, hex wrench, C32 and G34 brackets.

Cons: Too tall for a 4U case. Removing the fans from the heatsink can be difficult, as I've had to do in order to return it.

Other Thoughts: Newegg lists this item as being smaller with the fan attached than without the fan, which I found out is not true. Also, Newegg lists its dimensions (With Fan: 6.1" x 4.96" x 2.56") out of order. Normally, dimensions are LxWXH but the height is actually over 6.2" according to Noctua's site. The heatsink/fan work great and Newegg's problem with dimensions is no fault of the product so I will not knock the rating down. However, keep in mind that this fan is just a bit too tall to fit into a 4U case. I was able to get it to fit with the lid sitting on the heatsink, but couldn't close it. Ended up returning it for the NH-U9DO.

Also, ensure that your motherboard is compatible with 3-pin fans. My motherboard, the ASUS KCMA-D8 requires a jumper setting to be changed to use 3-pin fans.

Pros: very nice, stylish, huge heatsinks. keeps my dual opteron 6272's nice and cool. i love the dual fans to help airflow through the case.

Cons: tricky to assemble, and one of the noctua heatsinks i ordered had a few noticable dents in the top. nothing problematic, but i expected something nicer with the high pricetag. only one of the heatsinks was in view of the clear panel side, so i was able to place the flawless one in view.

Pros: THis thing fit perfect, no issues, does what its supposed to do.

Cons: none

Pros: This fella is VERY quiet and does a great job. It comes with its own heatsink paste, so no need to purchase more. Works with my ASUS double CPU motherboard.

Cons: none

Other Thoughts: It is a huge device and blocks three slots on my motherboard. Installation is quite a trick. The cooling fans attach with these wire clips and it does require a bit of a feat of strength to install them.

This is not really a con ... it would not have killed ASUS to allow a bit more space between the CPU and the first socket. Likewise, the clips are strong for a reason, it is not a task for folks with wimpy hand strength.

REMEMBER: Attach fans to the heatsink BEFORE installing it. Otherwise, your tool could slip and trash your motherboard.

Pros: This is in response to planetbrian's review. He hated the fact that this had 3 pins, and that servers mostly use 4-pin connectors. This is clearly stated in the specifications, and planetbrian is simply upset because he felt he couldn't be bothered long enough to check these specs and ensure he was buying the correct item for his needs. I truly hate when people give bad reviews because they bought the wrong item, not because the item has problems. If you bought the wrong item, suck it up and return it, planetbrian, and read the specs for what you're buying next time.

Cons: None - used this and other models of Noctua heatsinks with fantastic results. Noctua also sent me replacement and upgrade accessory parts for free when I called to buy them.

Other Thoughts: People, please don't leave bad reviews when you get the wrong item because you didn't check it thoroughly enough. It throws off the rating, and just shows how irrelevant your lack of knowledge is.

Pros: I'm getting 39C (100F) ambient case temps during continuous 80% CPU utilization on 12GB RAM (out of 32GB); 32C (87F) otherwise. Fits (just barely) into a SUPERMICRO CSE-733TQ-665B mid-tower (modified slightly and with the SuperMicro PWS-865-PQ 865W).

Cons: These should have 4-pin fans. Without them, I have to take off an egg. I know, I know, the design doesn't need them. But still .... 'Can't install all fans to spec when using a SUPERMICRO MBD-H8DCL-6F-O motherboard, though; not enough space to put two fans between the processors. (I installed the spare to the back of the case; even that is tight, but it almost lines up with the others to provide equivalent throughput.)

Other Thoughts: I use the system for a Digital Audio Workstation (DAW). For a DAW, these fans are too loud to use as a recording machine (even when set to ULNA). But as a rendering machine they are OK. I didn't trust that a Socket F solution could cool adequately considering the load that I planned to subject this machine to. I see that I might be right.

* 2 x AMD Opteron 4284 Valencia 3.0GHz Socket
C32 95W 8-Core Server Processor OS4284WLU8KGUWOF
* SUPERMICRO MBD-H8DCL-6F-O ATX Server Motherboard Dual
Socket C32 AMD SR5690 DDR3 1600
* 4 x Kingston 8GB 240-Pin DDR3 SDRAM DDR3 1600 ECC
Registered Server Memory DR x4 Hynix C Model
KVR16R11D4/8HC
* 2 x Noctua NH-U12DO A3 for AMD Opteron CPU Cooler
* SUPERMICRO CSE-733TQ-665B Black Pedestal Server Case
(modified slightly and PSU replaced with the following)
* SuperMicro PWS-865-PQ 865W Single Server Power Supply
* 4 x Western Digital VelociRaptor WD3000GLFS 300GB 10000
RPM SATA 3.0Gb/s 3.5" Hard Drive -Bare Drive

All bought from Newegg!!!!

Pros: Looks nice, but it only has 3-pin fans. This is absolutely not acceptable for a server. Servers come with 4-pin fan connectors for a reason. This was marketed for servers and has desktop quality fan connectors. All new motherboards, servers and desktops, have 4-pin cpu fans now.

I am sending this back.

Cons: Old style fan connectors on a premium priced product.