With Micron I jump between BTG, ETH and Monero currently.
With slower memory I cannot see how ETH would be relevant to mine today (other ethash coins might be profitable some minutes per day).

With Linux and Win7 (IIRC) it still works.

And the largest number of video cards is 13 on the same BIOS IIRC (mining cards without video is something else).

But how are the newer bioses for CPUs with a larger number of lanes than 16 (e.g. ThreadRipper)?

The number of physical slots is not important since simple $15 splitters solve that (not counting the reduced MTBF due to more minimal quality items).
I guess that PCI switches (those with $80 switch chips, e.g. the one with 8 USB riser connections) does not increase the number of video cards to the bios.

It would be really interesting if GPUs could be flashed into a "miner card" without video out (from the bios perspective). Then there could be more options for building 10+ card setups.

With only two rigs my experience is limited but it seems like 12 card rigs is a sweetspot when you know how to setup a balanced rig.
Testing you way forward with parts and settings, a 2-4 card rig is much more appropriate.

I tried to use 10 (on Z270P-D3) before i noticed that that mobo did not allow more than 9 (but one GPU got "ROI" by RMA so that solved itself).

Works, but it does not make you bios handle any more videocards (8-13 depending on bios etc)
https://bitcointalk.org/index.php?topic=2204115.msg33127677#msg33127677 (some testing with how it shifts the PCI addresses.
I have no mining cards to see if those could be added on top (as with the 19 slot Mobos which can take 13 video cards max).

The Acorn Nest X2G could be something else to consider. A lot more money but the PCI switch (there was another 8 USB card for about $100) might give other max number of video cards (but maybe not, it's probably the leftover lanes from CPU that dictates the number).

Got some BTG exchanged today, but it's several days apart (and last one was stuck for more than a week).
So things could move faster.
No such issues with exchange of ETH though, that gets processed several times a day.

Finally got a transfer made at 08:03 UTC today, so it's working, somewhat.

Even though the announcement mention "- BTG, DGB are enabled on Bittrex. BTG, DGB auto exchange will work too."

I have had about half a BTG sitting on Exchange for many days now. It's mining to the Auto Exchange wallet as it should and it's moved to the Exchange as expected, but it's not being transferred to my Auto Exchange coin.
Is my volume of BTG too small (a very small rig mining about 0.02 a day)?

For initial purchaser, yes.
But there is no such law handling a second hand private purchase.
So resale and warranties are up to the manufacturers goodwill.

The miner is run by root and it has the same owner/group and permissions in both places.
-rw-rw-r-- 1 root root 143 Jul 29 11:32 epools.txt

Interesting that the Warranty info and especially its transferrability is so well hidden that its very common to see GPUs being resold with "30 month warranty" even though it's a brand that does not allow the warranty to be transferred.

Uninfomed smucks are good customers...

I'm having a minor inconvenience with the -epoolsfile option.
I'm using claymore trough Simplemining.net which means that finer folder gets swiped when i switch miner.
This means that the epools.txt gets removed every time and my solution is to copy in a backup from another location.

I have tried to add -epoolsfile and the direct path to the backup file but it does not seem to be able to read that file for some reason.
-epoolsfile /home/miner/epools.txt                                                                           

gives this when I press "r"
This refers to the pool entered on the command line.

if I copy this epools.txt to /root/miner/claymore-eth-v11.8/epools.txt and remove the -epools on the command line it gives the following in the log:
Which means it reads the file with three pools + the one on the command line

So am I entering the path to the alternative epoolsfile wrongly in some sense or is Claymore unable to use absolute paths (so ../../../home/miner/epools.txt would work better)?
Nah it gives

Keep track of your imperial units.
T(°F) = T(°C) × 9/5 + 32

So a delta T of 6.7C is the same as a delta T of 12F, the 32 is just an offset for when the two scales are zero.

https://www.engineeringtoolbox.com/cooling-heating-equations-d_747.html

hs = cp ρ q dt

hs= 20 kW
cp = specific heat of air (1.006 kJ/kg C)
ρ = density of air (1.202 kg/m3)
q = 2000/3600=0.555555
dt = temperature difference (C)

So with 20kW that airflow will see a delta T of 20/(1.006*1.202*0.55555)=29.8 C

Lets take a real cool ambient temp of 20C, that would mean that the air exiting will be 60C, and you cards will then most probably will be running at 80+C.

Double the Air flow and the deltaT will be reduced to half, with exit T of 45C, a much better situation.
The math is actually really simple when you reduce the situation to total air flow and total power inserted to the system.

With very controlled airflow (so all cards get the ambient air and no exhaust from another card) the cards will see a lower peak. Water cooling would be even better to control where the heat goes. But the heat transfer by air is till the same, 20kW transferred to 2000 m3/h air gives deltaT of 30C.

If that is 144.5 algo I got 203 on 9x (22.5 avg) so not really the suggested 23 (140c 1400m 80w).
The same get 210 Mh/s in Ethash (probably micron, and that with -100c 1400m 75w).

If 144.5 it does not sound that low.

BTG is till not being transferred...

I got 203  Sol/s on 9x1060 #GB with micron memory, 22.5 average (140 core, 1400 memory and 80W settings in simplemining.net). Add 10% for 6GB I guess. But ETH still pays better than BTG for me.

Ambient air FTW.

It's sad that the low delta T makes it near impossible to reuse the heat to something (e.g. create some hot water, although cold showers is called for in 100+F ).

A mining shed would be a good place for an air/water heat pump "outdoor" assembly, recouping some (very little of course) of the power lost out the vents.

Windows is also closed source...

More excitement at 45:00 about the Nest X2G. Selfcontained 2xAcorn+4xGPU unit with no work going to the rest of the system (unsure if the PCI switch will expand on the max 13 video cards on a system, or how many lines the Nest X2G needs from the PCI slot? Apparenty 2.0 X8 (1:05:00).

They do mine ETH unless you deliberately choose a flawed OS. Currently epoch 199(2.55GB).
But more than 3GB is safer for the future since memory size seems to be the current "solution" to make algos harder for ASICs.
I currently mine BTG (Equihash 144,5) on some 1050 with 2GB VRAM, but will that be possible 6 months from now, I don't know but probably not.