Are power supply calculators any good

[Bart1999]

I am building a new PC with the specs below and based on a range of supply calculator website it's recommending between 400 and 500 watts. How accurate those websites are?

• - Ryzen 7 7800XD
• - RTX 2070 (Will upgrade)
• - 32GB DRR5
• - 2 SSD (1.5T)

[filpo]

2 minutes ago, Bart1999 said:

How accurate those websites are?

400 to 500 is about correct. i trust pcpartpicker and it said 466w so I'd say it's around that

which psu calculator exactly?

[Hinjima]

5 minutes ago, Bart1999 said:

I am building a new PC with the specs below and based on a range of supply calculator website it's recommending between 400 and 500 watts. How accurate those websites are?

• - Ryzen 7 7800XD
• - RTX 2070 (Will upgrade)
• - 32GB DRR5
• - 2 SSD (1.5T)

I usually check each individual part so the 7800X3D will consume around 120-130w at full power while the RTX 2070 draws 175w at 100% load.

Say another 120-150w for the rest of your system you are at 420-455w at 100% full system load.

Full system loads does rarely if ever happen during normal gaming.

The PSU calculator seems quite correct

 

A decent 650 or 750w will do the trick, you want a bit higher wattage PSU so you hit the efficiency curve of the PSU itself.
 

[WereCat]

I mean a quality 500W unit will be sufficient for this and in theory a quality 400W would be as well but good luck finding a quality 400W for a reasonable price.

Generally it's best to get something like quality 750W for future upgrades. Yes, it costs more but it does not cost twice as much as a quality 500W so unless you're on a very tight budget I would recommend going with more.

[RONOTHAN##]

2 minutes ago, Bart1999 said:

How accurate those websites are?

Not very. These sites use very naive calculations, mostly just adding the rated TDP of all the parts and calling it a day, not taking into account things like current spikes, inaccurate TDPs, etc. 

 

Generally, the way to go about this is to look at what the GPU recommends and find a highly rated unit with that power rating or higher. You can take into account the CPU depending on how power hungry it is (most GPUs assume a ~150W CPU, so if you have a 80W chip like the 7800X3D you can lower the recommendation by about 50W). The 2070 recommends a 550W unit, so I'd try to get that or higher though you should be OK with a well rated 500W, but if you're planning on upgrading, you really should get a 750W+ (preferably 850W) due to modern GPUs being very high power draw. 

[scruffballz_86]

800 watts 80+gold should be overclock proof !!!