250 watt PSU good enough for DC?

[grandpaflo]

I have a newer system but it came with a 250 watt PSU, should I swap in a more powerful PSU prior to venturing into DC? The system will run DC 24/7 in a non air conditioned environment, set on 100% CPU usage.

 

[petrusbroder]

Depends on the hardware:

• Do you intend to use a GPU on a newer graphics card too? How much does this graphics card use?
• What kind of CPU do you use (older multicore CPUs can use up to 135 - 145 W by themselves)
• Do you plan to overclock?
• How many DVD-R/W, HDD, how much RAM, what type of mother board is it?
• How many fans to keep it cool?

If it is a CPU-only cruncher, with a newer type of CPU, not overclocked, one HDD, one DVD-R/W, 2 - 4 sticks of RAM and if you won't use the graphics card for crunching then 250W should be enough.

The CPU could draw 90 - 100W (if overclocked up to 30% more), usually the HDD 5W, the DVD-R/W 10W, the mobo 10 - 20W, the fans 2 - 3W each and a very powerful graphics card can draw up to 300W alone (worst case scenario).
You have also to remember, that the PSU is not 100% efficient - so calculate 70 - 90% efficiency (depending on make and quality): you can thus load the PSU with 175W - 220W.
I have used - on older C2D-crunchers, without graphics cards and just one of each storing devices - a 300W PSU without problems. Now, when I run GPUs I use a "gold" 620W PSU at least ...