Hey Yun9999,
I just want to thank you for your vast amount of knowledge and tips/tricks you have posted in this post and your part 1. I finally got around to reading the entire thing and i kinda wish i did from the start when i was researching GPU mining 2 weeks ago.... I kinda already made a few mistakes that might cost me some money i didnt need to spend.. but oh well we all learn from our mistakes....
I am currently running 4 GTX 1080ti's mining, have 2 sitting on my desk waiting to mine and 2 more on the way i bought lastnight to fill a rig im building this week....
In the short amount of time mining with them my watercooled pc maintains 38c and has been super stable... literally been mining with it the last 7 days straight on zpool.....my 2nd pc which has 2 air cooled cards in it has been a heart ache, has capacity of 7 cards on mobo, its my old gaming rig i retired in January... but i for the life of me cant get any of the risers to work on the mobo.. just so annoyed with it, sent the first brand back to amazon, ordered brand 2, they didnt work, yesterday i got brand 3 and still no luck.. so its only running 2 GPU's and im already seeing the issues with running it on air i have had to restart the computer and miner a handful of times already in the short amount of time its been in service.. so i have been looking into ways to cool things better because i have been running this computer in my friends garage, since i live in a condo and dont really have the ability to scale more than a few rigs... so i decided to torture test it in his garage in the sunny florida and the temps have been suffer on the hashrates during the day due to thermal throttling even with running it at 65%tdp and less...before actually reading your post i did order a rosewill l4500 4u case like you use.. unfortunate the estimate from newegg on shipping it is the 2nd week of July... i think you bought all of them
A quick possible low costly mistake i made 2 days ago was order a refurbished dell t-series server workstation for $160. I was doing research and found a posting of a guy who mined with 300+ GPU's and the way he cheaply scaled his setup was with a bunch of the T-series rigs at first, because they either come with dual xeon cpu, 8gb ram, 4 PCIe mobo or the 5PCIe mobo and a 875watt power supply with a copy of windows 10pro.... i ordered it because literally every combination of cheap mobo/cpu i would lookup on newegg was either shipping out like a month from now or out of stock.. so i kinda purchased it out of not wanting to wait and it will be here tuesday, since ordering it i have found out that the 4 x 8 plugs it uses on the PSU for pcie expansion are PEG 8 pin (sigh).. which is kinda annoying as i need to either buy adapters or cut them off and re-pin them for 6+2 connectors... currently the power reported used on my 4 gtx1080tis with the tdp settings im using is around 550watts, but just to make sure id be covered i went ahead and bought a EVGA 1300 watt PSU as a just in case if needed PSU.. this purchase was to get my 2 spare cards up and running making me money, and since i will have 2 extra slots or possibly 3, i went ahead and bought 2 more cards last night to fill the rig to 4 to bring my total mining to 8 once its up and running...
Im seriously doing a lot of research into the possibility of scaling up from 8 and im debating between 3 ways and i wanted to get your input on cooling them...
idea 1: would be a similar idea to your shed build, but the setup would be slightly altered to use closed off spaces.. im really liking the idea of using the server cases to keep hot air from recirculating, so i was thinking of building a shed with a hollow wall inside on the side the exhaust fans are at, this would act as a giant duct/space to direct the hot air out of the shed... i could build the wall out the full length of the one side or build it in sections and as i build 4U case builds i can basically unscrew the plywood section for that chamber leading up and cut off sections as i add more rigs and just slide the case into its spot and screw back the wall plywood to seal off the area, this would keep the hot air in the back of the server case trapped in a small area and the fans you posted would act as a vacuum source to suck it out of the shed, then fresh air would enter the front of the case... I could build the entire setup out of cheaper wood instead of buying the sexy server frame boxes like you have and just paint them with fire resistant paint..
Idea 2: This idea is kinda an odd one, when i searching the internet i came across a small 18 gpu setup a guy designed that sounds logical, but at the same time im kinda unsure on.. i may buy some stuff to test it on a small scale with a 2 card rig for concept... basically the guy used like i think 4/5 inch pvc pipe that ran above each shelf of his shelving above the motherboard, basically he cut small holes big enough for him to slide the gpu and riser card inside sitting it on its side with the fans facing upwards inside this pvc pipe and then just taped up the hole sealing the card off inside the pvc pipe.. He had 6 GPU's running the length of the pipe. The pipe with the GPU's inside had a stack of 2 like 140mm or 180mm fans at the end of the pipe blowing air into the pipe across all the GPU's, then the other end of the pipe ran into a T fitting into a vertical pipe which ran up and over to a window in his garage to exhaust the air... the guy had 18 GPU's running in this system claiming to be able to maintain around 60c with ambient temp air... but the poster never added anymore info after his initial build since 2014... the concept seems logical in a way to be honest...
Idea 3: This one is the most expensive to do upfront, but could be rewarding if it allows me to mine with the GPU's for much long period of time... Since playing around with my gaming rig with gpu minig, i have greatly loved the silence and amazingly low GPU temps my loop can maintain cooling 2 x gtx1080ti's with an external Phobia 1080mm radiator mounted on the wall under my desk on a french cleat with spacing for air flow for fans... the system just seems sooooo stable and runs so much smoother due to the low temps on the actual GPU's... The costly part is buying a waterblock for every single card, but im unsure how far i could go on a single water loop before the amount of GPU's causes the loop temps to be to high... and im unsure if its worth the extra expense if as a miner you rotate your cards every year or 2.. being new these are questions im unaware of... since im sticking to the GTX1080ti theme right now, i have noticed i can purchase 5 different 1080ti's that come already watercooled from the manufacture for around $800/ea, which is cheaper than buying the waterblocks seperately, but there is the possibility of getting a bulk discount if i can talk ekwb into selling them to me at a volume rate... the pump and radiator could be the easy thing... i can either go water to air and use something like a car/semi radiator outside the shed or do water to water like the btc miner in California in the news who stuck his water cooling radiators in his pool, the pool water soaked up the heat