Bitcoin Forum

I have the following.

Antec HCG-750 750w Power Supply, supposed to have a max W of 750, up to 750 available for the 12v rails and 150 for the others: http://www.newegg.com/Product/Product.aspx?Item=N82E16817371049

1x MSI 6970 (210w?)
1x Power Color 5850 (155w)
1x Visiontek 5770 (95w)
1x Sapphire 5770 (95w)
1x MSI 5770 (95w)

AMD Athlon 64 x2 5200 brisbane
Foxconn Destroyer
40g HDD
5 120mm fans

As far as I can tell, after the video cards I have 100w for the system.... am I too close to maxed? I do have an 800w available... is it worth the extra 50w?

I believe, you want to run your power supply between 75-85 percent load to get the best efficiency. I'd say 100w free, you should be good. Let others chip on their knowledge as well before taking my advice.

How much power do your five fans, cpu, hdd, and mobo altogether consume? Assuming you are not doing any overclocking or overvolting of any components in your system?

it looks like that is a multi rail power supply. its always best to have a single rail for miners. I would think it will run 4 without issues but am skeptical on 5.  Nice thing about that cpu though is you can underclock brisbanes to around 10 watts. If it does post all cards I would underclock/undervolt at least one card for some more breathing room, for example the 5850 at 775 gpu and 1.02v almost always works for me

cpu is rated 65w... but I think that is full-load. I'm probably going to swap the 5850 for another 5770, which will free up another 50w, so I should have ~150 for the cpu/mobo/fans/hdd.

I'm running two flashed 6950s with 1536-shaders in my desktop with a 2500k and an 80+ Bronze PSU at 900MHz for 800MH/s, and I'm only pulling 350W at the wall. I don't think your 6970 will draw 210W.

Well, it doesn't seem to be stable... is there any way to know which 12v rail each cable is coming from?

I'm running these 5 cards and drawing 740W at the wall with a 750W 80PLUS Gold HALE90. Assuming 87% efficiency, this is about 644W, still more than enough headroom.

5830 @ 705/150/0.95v: 230 mhash/sec
5830 @ 880/175/0.95v: 284.5 mhash/sec
5850 @ 1010/211/1.088v: 421.5 mhash/sec
5850 @ 1035/216/1.088v: 432 mhash/sec
5870 @ 720/145/0.95v: 331 mhash/sec

CPU is an Athlon II X2 250 (dual core 3GHz) underclocked to single core 800MHz 1.05v on an ASRock 890GX Extreme4

Not sure, but most quad rail supplies seem to do two to the PCIe plugs, one to the CPU, and one to everything else.

You can even go 0.85-0.9v with your underclocked athlon II. My X2 250 on my Gigabyte 890GPA runs fine at stock clock (with CnQ and no core disabling) on 1.15v (default is 1.4v) even if the CPU is at 100% utilization.

I didnt mess with voltage because I didnt want to troubleshoot it if it started acting up. The voltage is at default because cool n quiet has its own un-modifiable voltage, so all I really did it just turned off a core and went into windows power management and put the minimum and maximum CPU duty (whatever its called) at 5%.

I ran 4 x 5800 series cards on a 650 Corsair HX series.... Damn PSU got hot as fuck but ran fine :P

In my experience 80Plus Gold series PSU handle loads at the limit very well without heating up a lot. Vanilla 80Plus PSUs do not cut it with the heat output of the PSU, my two ANTEC 80 PLUS get very hot (touch thermometer), while the Seasonic and Superflowers 80Plus gold stay warm in a room with 110F ambient temps. 

Good to know, thanks for the input. I pulled the 5850 and replaced with a 5770 and the box is stable.

or another way to run a power supply more stable at the limit is on 240v... another thought 5770's use quite a bit more than 95 watts overclocked more like 120-130 watts