Overclock

If you look carefully in the last photo you will spot the pedestals of 4 big fans. 

I guess he just blasts his installation full frontal from one side.

I used two similar fans in my bitcoin setup, they are very strong... if you position them correctly it should do the job.
It then also depends how the whole room is ventilated ofcourse. (how the accumulated hot air actually leaves the room, and how colder air is reintroduced)

So:
1) every GPU has a fan
2) big 60 Watt Fans pointed at the whole installation.
3) room ventilation

All those things have to come together if you plan to operate such a setup for years.

I wonder... is mining spreadcoin worth the electricity?

For me it seems the project which started as ultimate "spread the coin", became the ultimate "concentrate coins"

No pools, actively killing attempts to make pools.
All this achieved is removing small miners from the project, concentrating the hashrate into 3-4 big farms. Who can use "private" miners

Please explain me where am I wrong...

I regularly followed the project during 2015 - exactly because of claimed decentralization. And mined wth several cards. So I don't need pool.
The project needs to address this problem
Pool or single miner - whats the difference?
Which is easier to abuse?

With all due respect (you have very extended knowledge and skills)
the "pool" you got set up is a workaround the decentralized nature of spreadcoin.

YES - it is a "pool" mining, and NO - there is no "breach" in spreadcoin's design,
which is meant to prevent/limit whatever pool mining. Let's not do semantics -
you proved there is a workaround for pool-like mining.
You might say: "It's not pool-like, it is pool mining" and technically you will be right,
but personally signing each miner's miner is an overkill just to prove a point.
Also you eliminate miner's choice of software, and while many people might be ok with that,
I (and many others I'm sure) will not use this, just because I'm left with no choice.

I already regret for this reply, since all "pool related" replies just have to be left without response.
I encourage georgem to put a link in the OP with detailed SPR pool discussion.

The Spreadcoin network is currently very small. The total network hashrate is only 439 Mh/s. That's tiny.
It's because of the low price but it was in the Gh/s region and probably will be sometime in the future...

It all depends on the price really - people mine what's profitable.

So currently yeah, it's safe to say that only a handful of people are mining all the coins, they are not exactly big farms by any means (which is why Ocminer aptly used quotation marks around the word bigger).

If, and when service nodes come so will the interest for the coin. Interest would push the price which would push the hashrate and the number of miners up as well causing a big and healthy network.

Before I started mining this coin I had 0 experience in the mining world. I heard about bitcoin a couple times but knew nothing... So I searched forever to try to figure out how to mine anything and it took me 2 days to figure out how to mine Litecoin and X11 coins. Once I saw this it took me less than the sync time to figure it all out. I have been mining off and on since the very end of Feb with 2 GTX 980's and I have just under 10,000 SPR. That is pretty amazing for solo mining a coin that gives 5 per block as far as I'm concerned. I'm not a "big" miner and I definitely don't have a "farm." When you have something like Dash for example, 2 pools control I think like 80% of the network. So if you want to cripple the coin all you have to do is take down the 2 computers controlling those pools and bam, 80% of the network gone... Those pools act as a centralized point in the network, or, a central point of failure.

As far as your network problems I cannot say, I have never once had a problem submitting a block that I have solved at all and the only thing I had to do was follow the wonderful Youtube video that walks you through everything step by step to set everything up. I think my windows firewall did ask at the beginning to let Spreadcoin through and I had to accept it but I cannot remember for sure.

Well, that is just my 2 cents... I'm sure if I was wrong anywhere in this post everyone will be correcting me.

I am right with you on that. I will say that there are a couple people who do solve a lot of blocks but for the most part I would say it's pretty diverse. But even if there was 4 or more big whales, how is that any different from a pool? I tried to mine Dash in the biggest pool of the time when they had over 50% of the total network (coinmine) and there was one whale who had almost 50% of the pool. After a whole day of non-stop mining I had maybe .0002 Dash while that whale of the pool cleaned house. So I honestly fail to see how pools are helping the small miners anymore than no pools at all. The only thing pools help is themselves with the fees they charge.