I would like to second the complaint about people quoting images. My "good" computer (below) runs bitcoind, so the machine I am using to browsing the web is 10 years old.
This is my response to to
Project: Stealth Mining Rig thread. Only took about 10 months
Specs- Antec Sonata Case (not sure of specific model)
- Antec EarthWatts 380W "green" PSU (see? it is painted green...)
- 3Ghz dual core Pentium D processor (power hungry)
- 4GB RAM (3306MB available)
- 60GB SSD (expect to need to replace it by the end of the year)
- 80GB SATA disk (used for unrelated encrypted jail)
- 100Mbps RTL8139 NIC
- 9600 baud serial console
- FreeBSD 9.2 (apparently I have to figure out how to migrate to 10.0 now)
- ASICminer new-style blade (10.7 GHash/s)
The grey cable is a serial cable (serial console over a null-modem cable). Removing the 2MB video card freed 124MB of addressable memory. I had to install a RTL8139 NIC because the on-board LAN would lock up when I tried to transfer bootstrap.dat over using SSH. There is no performance loss, since it is only plugged into a 100Mbps router/switch anyway.
Besides being discrete, the metal case blocks Electromagnetic Interference (EMI). I actually had to move the machine almost directly below the TV antenna (out of picture) because the front of the case does not block EMI as well as it should. The machine is also relatively silent (case is designed that way). With the fan on high, I can easily hear it, but the controlling machine (Pentium 166) is still louder.
As you can see, I crammed an ASICminer new-style blade into the case. The only fans are the PSU, the CPU, and the one to the upper left (120mm IIRC). I tested that the air-intake on the CPU stayed below 38°C with the fan on low; with no miner in the case. Did not re-test with the fan on high and the blade in the case.
Cable management is key. It helps that the drives are partitioned from the rest of the case. I wanted to use a PCI-E 6 Pin -> dual molex adapter , but was not able to find one locally. Ended up using a 2 molex -> PCI-E 6 Pin adapter I got from a local computer shop free-of-charge. Apparently when they are building systems they always get an extra one. They come with video cards, but sane builds will use a PSU that includes the 6 pin connector. I made sure that each connector uses its' own wire pair going back to the PSU. This meant I had to run a different cable to the drives: one of the SATA power chains had a molex connector at the end, while another did not. I do share blade power with the vent fan (about 3W, 0.25A) and front LED though.
I was disappointed by the lack of mounting holes. The blade sits on a boxy plastic tube with a slot for the fingers cut into it (possibly not needed, but did not want to risk it). I have a zip-tie wrapped around the fan connector (left), fastened to the case with a series of half-hitches. I have insulated wire running through the two small holes on the right side of the board. That is looped around internal case structure.
I did not want any add-on cards at all. However, I think the NIC is low-profile enough to not cause problems. Because the spinning disk is SATA, and only has data used by its' jail on it: it is actually hot-pluggable. I learned the hard way that the ASIC miner blade is
not hot-pluggable. It worked no problem once (the one wire gets hot until you plug in the second one). However, the second time I tried it, I got a big blue spark, and the PSU shut-down. Toggling the hard power switch got things working again.
I was surprised how much extra power P2Pool uses. With Bitcoind and Slush's stratum proxy running (pointed at Eligius), the CPU idled between 700-350Mhz (0.07 load average). Running P2Pool, the CPU stays between 2-3 Ghz (0.30 load average). This results in a power draw of an extra 20 Watts or so. I saw
one report that pypy (a just-in time python compiler) works with P2Pool, but have
not been able to get it working yet.
Update:
Got pypy working. Results are inconclusive so far, but looks like about
a 0.20 load average (33% CPU usage reduction) the same CPU usage at the cost of
more than double triple the memory usage (from about
just under 0.5GB 400MB to
over 1.0 GB 1200MB). CPU still stays at high clock speeds.
Edit: It appears the initial drop in CPU usage was simply reflecting the reduced network traffic the node was seeing after restart.
Power Usage- Pentium D Machine = 94 Watts (idle, with fan on full)
- ASICminer blade = 80W (28 W idle)
- Pentium 166 = 36W
- VDSL modem = 4W
- Netgear Router = 2W
- Subtotal = 216W
PS: I am aware that newer boards are more power efficient. The Pentium D was probably the most power-hungry design ever made by Intel. They went back to Pentium II based designs for their next chip (the Core 2). At 92Watts of idle power draw (fan low), I am convinced something is wrong with the machine. I don't think the board supports a calibrated power supply output resistance of 1.6 milliohms required by the processor. Stopped short of thermal imaging because I could not find an appropriate camera. I disabled everything not in use on the board, with no effect. Most my old computers draw about 40W with non-essential components stripped.
