Quote from: molivil on January 29, 2018, 11:52:29 PM

I would like to thank all of you for your valuable input over the years on this megathread. It's been great reading some of your inventive ideas and comments on hardware and altcoins, and it's been interesting reading the back and forth discussion about Pro's of ASICs and GPU's as times have changed. And your experiences on what has worked out, and what hasn't.

I first got interested in GPU mining around when the April 2017 gold rush hit, so I'm fairly new on the scene. I've built a few GPU miners (5 so far) and used different ways to deploy low-cost mining gear. I've followed this megathread, BBT, and several other mining related channels. I also appreciate you Voskcoin for all your hard work, great videos and your approach on low-cost ROI and rapid deployment ideas, starting with Phil's three card builds and going on to the 13 card ROI-monster builds. Phil has indeed been an inspiration to many of us. I would like to contribute my own experience and success story regarding some pre-built computers I've used.

A while ago Phil tried a refurb PC miner, and thanks to his efforts, I was motivated enough to look into it myself, since I'm also prioritizing ROI, rapid deployment and small initial investments. Finding the right model was a challenge though, as with limited documentation there is always the risk that the feature set of proprietary computers don't align with the requirements of mining. I figured that I'd experiment anyway. I started looking for commonly available cheap PC's, emphasizing quantity of PCIe slots and lowest price. I went through many models from Dell, Lenovo and HP.

In the end, and after weeks of deliberation, I settled with the HP Z210 CMT workstation PC. One reason is that they're pretty cheap and common on eBay, and I see them go anywhere from $90 to $150 shipped to contiguous US.

What I like about them is that they come with almost everything needed.
- CPU Intel Core 2nd Gen (Core i3-2120, Core i5-2500 or Xeon)
- RAM: 4GB or 8 GB
- Hard disk: 320GB - 500GB
- OS: Major refurbishers sell it with a licensed OEM copy of Windows 10 x64
- 5 PCI-e slots ready to go (two of them are full size PCI-e x16 slots)
- 400W power supply with one PCI-e 6-pin power. Base system power usage at idle 40 watts.

So, I buy the base system for $90, then buy a 2nd power supply for maybe $55. I also buy a $5 ADD2PSU board, 5 risers $6 each, and mount the risers on a piece of picket fence from Lowe's at $4 each. Total system cost minus GPU's is around $195.

At the time of writing I have two HP Z210 based PC's mining away for a couple of months and have had zero issues so far. Each one has five GTX 1060's connected with Molex style risers. One GPU is powered by the HP Z210 itself, and the rest are powered by the 2nd PSU with 4x PCIe power and 4x Molex connectors for the risers.

All my miners are running Windows (w/Teamviewer). Choosing to go with HP Z210 CMT I get most of everything included, so I don't really need to build cases or buy components. I don't usually buy the operating system either as it comes preinstalled.

The only problem I've run into so far is that the HP's mobo isn't compatible with standard power supplies. You'll have to run it with the included PSU. Seems like the ATX mobo electrical interface is proprietary, even though the connector is the same. This is why I chose ADD2PSU instead of using a daisychaining cable to power the second PSU.

So in short;

Pros:
- Cheap. Common workstation PC's at the end of their useful lifecycle, so businesses recycle or sell to refurbishers.
- I like the idea of being able to buy a computer and just hook up the GPU's and extra power supply and start mining.
- No parts sourcing and hardware troubleshooting (also a con, see below)
- Usually no OS installation is required (if you're OK with Windows)
- Rapid deployment saves time (and time is money, right?

- Comes with one PCIe 6-pin power built-in so beginners can start mining right away.
- BIOS includes option to power-on computer after sudden power loss. Also schedule options available

Cons:
- I'm robbed from the joy of being able to build the system myself!
- Some proprietary stuff, like the non-standard ATX-motherboard power interface
- Power supply itself has a non-standard mount.
- Harder to find compatible replacement parts.
- Must use two power supplies.
- Must use risers.
- Only 5 PCI-e slots, as opposed to 6 or more with proper mining mobos

Gotchas:
- When buying the Z210, you're going to want to make sure it is the CMT model ("Convertible MiniTower") and not the Z210 SFF ("Small Form-Factor") version. Only CMT has all 5 PCIe slots. I believe SFF only has 3 PCIe slots. https://support.hp.com/us-en/product/hp-z210-convertible-minitower-workstation/5053199/document/c02794602

P.S. Sorry for the long post. I just felt like I had a lot to share. Thanks

One of my z220 sff came a very good Xeon CPU but 3 slots as you said.

It is really good for running moonlander usb sticks or sidehack 2 pac