Confused about power supply draw...

[branskyj]

Hi all,
I have a very nice PC which recently (after 2 years of work) started shutting down suddenly while working. I know there might be many reasons for that but lets just assume for a second it's the power supply that is causing the problem.

My current power supply is Corsair TX850 (850W) and was wondering if I upgraded to 1200W or 1500W (I might need it for when I buy a second graphics card) without changing any other component in the PC if I were to see any increase in the electricity draw/bill. That is assuming I get a reputable brand with high rate efficiency like 80+ and higher.

In other words- would the 1200W power supply draw more electricity just because it more powerful than the current 850W one or is the power draw all dependent on what the components require.

It may sound like a silly question but I do heavy rendering on a regular basis and leave the computer running for days and last thing I want is to spend my salary on electricity bill

Thank you.

 

[Blain]

It may sound like a silly question but I do heavy rendering on a regular basis and leave the computer running for days and last thing I want is to spend my salary on electricity bill

Spend those $$$ on upgrading to a CPU solution that cuts down on rendering time.

 

[branskyj]

I am rocking a i7 3930k and 2x i7 2700k for render nodes
Now... back to my PSU inquiry please.

 

[Nec_V20]

Unless you have something like triple SLI then I cannot see the PSU being the issue.

 

[frowertr]

Power draw is basically dependent on what the components need. You will also find that most PSU's will run more efficiently when running under a range of certain loads. Like this chart shows for Corsair's AX1200i PSU:

Also, going with a Platinum or Gold rated power supply could actually lower your bill, by consuming less power, if you are replacing a non Platinum or Gold rated supply.

 

[hackerballs]

minus a penny or two, the 850W will "spend" the same as a 1200W


Originally Posted by branskyj
It may sound like a silly question but I do heavy rendering on a regular basis and leave the computer running for days and last thing I want is to spend my salary on electricity bill

Lets hope you loaded up on Lots of RAM for all that rendering to make the times shorter

 

[branskyj]

Thanks for the replies, guys.

I suppose now a 1200W PSU would be an overkill but better safe than sorry (in case I decide to add more graphics cards in future).

Thanks a lot and have a good weekend.

 

[pcslookout]

Unless you have something like triple SLI then I cannot see the PSU being the issue.

How much power does triple SLI actually take?

 

[Torn Mind]

PSUs "waste" power by "producing" heat when doing its task of converting AC power to DC power(Note: energy is can neither be created or destroyed, but sometimes layfolk need a more intuitive explanation at first). A percentage of energy is dissipated as heat as electric current passes through the PSU en route to the computer components. That is the efficiency measure, which is simply the ratio of DC power consumption/AC power consumption. For example, if the unit reads 600 watts "at the wall" and we assume efficiency is 85%, 510 Joules of electrical energy is being delivered to the components every second while 90 Joules per second is dissipated as heat energy.

If you want to reduce consumption, you want a PSU with better efficiency. In addition, not only do you want a better rated unit for efficiency, but you also want to target your power draw to be at half of the PSU's maximum rated load, as that is when the PSU is most efficient.

PSUs are very "passive" devices and can be compared to the electrical system in a house. You don't use power until you stick something in a socket and "turn it on", and turning it on means "completing the circuit". If you are having issues and yet you are not pushing the components beyond their rated specs, it means something inside is defective OR, if enough time has passed, is nearing the "natural" end of its expected life. In your case, there is probably a defect somewhere in the circuitry, as even the first version of the TX850, which was made be CWT(Channel Well Technology) had Japanese capacitors throughout the unit.