most cost effective mining rig ?

[Hellobtc]

i am looking for outside of the box mining rigs

that mobo PSU and ati cards ?

[grue]

https://forum.bitcoin.org/index.php?topic=16076.0

[Jack of Diamonds]

card: 5850 at 900 clock can get 330 Mh
PSU: just buy a PSU for each card the crap one PSU cost under 10€ and usually are 250 watts

Nice way to ruin your mining operations fast.

Never skimp out on the PSU and buy "crap ones for €10 each". It's the most critical component in the entire rig.
In fact, it's the only part that you should spend extra money on, to assure you get the best quality one (that will also hopefully accomodate multiple GPU's).

To save money try to find deals on gpu's and motherboards instead. CPUs and RAM sticks can also be second hand, as well as casing.

[Jack of Diamonds]

Problem is that if the old PSU busts due to near 100% load 24/7, you can lose much more valuable components (gpu, motherboard, cpu, ram) which will wipe off your profit for the next 6 months if you're a small miner, or make mining infeasible because you will have to buy everything from scratch.

[IlbiStarz]

That guide says to ignore total wattage and focus on the 12v rail. How do you read the 12v rail specs? What does something like:

+3.3V@25A, +5V@25A, +12V@78A, -12V@0.8A, +5VSB@3.0A

mean? How do you know how many cards you can run on that?

[grue]

That guide says to ignore total wattage and focus on the 12v rail. How do you read the 12v rail specs? What does something like:

+3.3V@25A, +5V@25A, +12V@78A, -12V@0.8A, +5VSB@3.0A

mean? How do you know how many cards you can run on that?

for example, a 5850 uses 150W, max. assuming that all of the power is drawn from the +12v rails, it alone will need a power supply with 150W/12V = 12.5 A. keep in mind that other components will use power from the +12v rail as well. the other rails are barely used (for mining rigs), so don't worry about those.

[PulsedMedia]

crappy 250W PSU from the 90s will probably have reeeaally bad efficiency. Imagine running 10x200W GPUs, each with 250W cheapo crap, with 60% efficiency. You are drawing 333W per PSU from the wall. 3.3kW total. You spent 100€ on the crap PSUs.
Buy 3xCorsair/Enermax, say 120€ each. 360€ spent, but you magicly gain close to 90% efficiency, if not over. Let's assume 87%. You are drawing ~230W per card -> 2.3kW.
So you are saving 100€ per month right there!

100€ vs. 360€ -> 2.6months for ROI!

Nevermind reduced risk, warranties etc.
Ofc, the 250W cheapos, if bought new will have a warranty too, and are likely close to 80% efficiency, so ROI will increase to 9-18months.

Short term -> Cheapos good. Long term -> Cheapos not so good. (Unless the cheapo happens to be mfg by Enermax or Seasonic)

[PulsedMedia]

well i did find some 450W PSU for 12,95€

Link, want to check specs etc.

[Freakin]

is there anything wrong with running an older 350W PSU for the system and running the PCI-E plugs off a nice 850W corsair?