Power supply / Wattage

[Harag]

I'm just building a PC and I've put in a CPU that has 95 watt GPU with 275 watt, the total being under 400 watt so I put in a PS400.

However when I run the benchtest I got the BSOD for not enough power - running the system Info app as well I noticed I get purple output on the 3d mark app, and I can see the power usage go to 395 then BSOD (at 400).

I know putting in a larger 500+ one will solve the issue, but how do you calculate which PS unit to use?

Yes, MB, RAM, fans etc. all take power but they don't list any amount.

[Staalby]

You should always leave 20% headroom, as PSU operate at best efficiency just below peak output. MB, RAM ect watt usage is negligible at best. Use a 500w psu if you expect 400w usage.

This of course refers to real life. I didnt code the game. But there you go. :)

EDIT: Also, if you overclock, expect more wattage.

[Shinigami]

Yes, you should always expect a little more wattage than just what the CPU & GPU need.

[Harag]

Excellent, thanks for the reply. I put in a 500w PS and when I ran the 3Dmark app - the total usage in the graphic test came out exactly at 400.... All good now and sent back to client :)

I'll keep in mind to check fans / etc to see what else they have in their system.

[🦊Λℚ𝓤ΛƑΛᗯҜᔕ🦊]

Also do bear in mind that the cpu stating 95 watts is -NOT- the actual power usage of the processor. That is TDP or Thermal Design Power. That is a measure of how much heat the processor is going to produce when running so you can find a heatsink also designed (For example) 95 watts TDP. To figure out total power usage in game you need to run the OCCT app in infinite mode and wait for the power usage to level out to see what the actual system power usage is of the computer you've built.

[Harag]

Ahh cool, thanks for that - not got around to messing with coolers yet so good to know. Only recently started with the OCCT tool so still learning that.

[Andrew]

I was wondering if there was a way of actually breaking a PC in career mode. Is it even possible? Being the low level I am right now typically customers are asking for a 3d mark of 3148 etc, typically what I have been doing is upgrading the CPU and the GPU but I haven't Even thought of upgrading the power supply whatsoever. And im not breaking anything. It's crazy. Can you even break a customer's pc in regular career mode?

[PUC_Snakeman]

In PCBS 1:
PSU Wattage Needed = CPU Watts + GPU(s) Watts + 30
.... and overclocking adds more.

[Andrew]

Thank you! I was curious on how this worked. Thanks

[PUC_Snakeman]

You're welcome.