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PSU replacement and video card upgrade

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Dravenspur

Member
Joined
Dec 13, 2015
My PSU died a couple day ago. I'm looking at replacing it with an EVGA G3 750W, which has 62.4 amps on the 12V rail (I was using an 850W, turned out I might not have needed that much power). I'd like to upgrade my video card (I have an RX480 now...I was thinking of going to Navi...I don't care about ray tracing, plus the RTX cards are very expensive...I suppose I could get a 1660Ti possibly). Anyway, my question is, has anyone been able to find the amperage required for video cards outside of looking at the retail box? I would hope that 62.4 would work for Navi or the 1660 card, but I would hate to buy a new power supply, buy a new video card and then realize too late that the amperage isn't enough. I have searched on Google for a rating for current cards and haven't had any luck.
 

bigtallanddopey

Member
Joined
Nov 7, 2016
I don’t think you need to be going into that much detail, except maybe in extreme cases.

Obviously Navi isn’t out yet so we don’t know the power draw but looking at what you state is your budget range (1660ti) I would imagine even a 650 watt psu being enough for your needs. A 650 psu will often come with two pcie cables meaning you can run a 2080 if you wish.

There are some side points to that, such as how much other stuff you are running. If you have 10 hard drives, water cooling and other things plugged in then maybe you will need more power.

However I would say for an average user a 650 watt psu is a good sweet spot.


 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Right... Navi isn't out yet so we have no idea how much power it will use.

That said, I don't expect it to be over the 225W we've seen on flagship cards and like BTD said, a 650W is typically plenty for most single GPU systems including overclocking.
 

Bill_Bright

Member
Joined
Nov 22, 2018
Location
Nebraska USA
Anyway, my question is, has anyone been able to find the amperage required for video cards outside of looking at the retail box?
Did you try Google?

But instead, I use and recommend the eXtreme Power Supply Calculator to determine your minimum and recommended power supply unit (PSU) requirements. This is a whole lot easier than researching the individual components yourself.

Plan ahead and plug in all the hardware you think you might have in 2 or 3 years. This might include extra drives, a bigger or 2nd video card, more RAM, etc. I recommend setting Computer Utilization to 16 hours per day and CPU Utilization to 100%. These steps adjust for capacitor aging and ensure the supply has adequate head room for stress free (and perhaps quieter - always desirable) operation. These steps also add a little buffer for unplanned future upgrades or added hardware demands.

Note that all PSU calculators pad the results a little to avoid recommending an underpowered supply. But, by far, the eXtreme Outer Vision PSU calculator is the most conservative and therefore accurate. This is also because it is so flexible compared to other calculators with so many input and utilization options. Plus (and this may be the most important factor) they have a group of researchers on staff constantly researching new components for us as they come out, and updating their options lists.

Another nice feature is they include a recommended minimum UPS size to protect your devices from surges, spikes, sags (opposites of surges), dips (opposite of spikes) and brown-outs (long duration sags).
(I was using an 850W, turned out I might not have needed that much power)
Remember, the computer (motherboard, drives, fans, graphics card, CPU, RAM, etc.) will pull from the PSU only what they need. So if all your components only need 300W, they will pull from the PSU just 300W regardless if the PSU is a 550W, 850W or 1200W supply. And the supply will pull from the wall just 300W plus a little more due to supply inefficiencies (typically another 10 - 15% for most 80 Plus supplies). So no harm going bigger than you need, other than maybe a bigger dent in your wallet.
 

wingman99

Member
Joined
Dec 10, 2003
650 watt reputable PSU is all you need for single GPU and future upgrades with your budget.
 

Bill_Bright

Member
Joined
Nov 22, 2018
Location
Nebraska USA
I agree - and FTR, the EVGA 650 Supernova Gold is a great supply. You don't need Platinum or Titanium. It would take years to make up for the extra costs in the tiny bit of efficiency savings you pay for. Gold is plenty good enough.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Supernova's were MEH. Be sure they are of the Supernova G2,3/P2,3 lines which are newer and built on a top notch platform.