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Yes they are very quiet, i forced mine to 100% fan speed and it is in a living room and nobody cares about it, it is that quiet, like a gentle breeze or a typical household fan.
The fan bearings probably last longer in the correct position. Your image shows the unit lying down, all you have to to is stand it up, but the scroll fan remains horizontal. I'll show you an image, unfortunately my internet is limited and searching for images is difficult for me at this moment.
You could also imagine a toaster, with each hashboard being one bread. The controller ends vertical.
Hoping that you can see the image, this is the only correct way to use the R4 (You can push the data ribbons to the side).
Most images on the internet disturbingly show them lying down flat, never do that, it damages the upper hashboard and overheats the unit because the fan is not that strong even at 100%. BTW, you can force the fan to 100% by disconnecting the blue wire (4), you can gently take it out of the plug without harming it by pushing a little dent on it (same as all computer fans). I think this fan lasts longer when forced at 100%, but YMMV. Some fans do 3240rpm and some do 3000rpm. If this fan fails i don't know where to get more, maybe alipay/alibaba but I'm don't know where Bitmain sourced those from.
Also there are a couple of variants, I'm not sure how many batches were (6?), but it seems the later batches used even cheaper fans, and its a bit smaller. Suffice to say, many people burned them due to bad positioning, AND Bitmain also did poor soldering of parts in some batches.
The R4 was a good design concept, handled badly by its own company. Besides, they don't care about home users, only large industrial miners, which is why they killed it. They work with the same PSUs as the S9, and even that weaker variant that Bitmain once did for them that could do 120v. 845W @ 8.5TH/s using Dec 2018 firmware according to official specs. Its pretty much a 2 hashboard S9, in fact the controllers can be swapped, but remember the S9 one expects 2 working fans with their firmware...
I think not all batches used the same Xilinx 1g ram controller, i remember a 512mb ram one being mentioned somewhere.