And your current PSU is...?
You could be hitting it at its most inefficient spot. It could be 80 Plus Bronze, White, or below the 20% load level where manufacturers sacrifice low level efficiency to get that coveted 80 Plus mark. Who really knows how much power it's really putting out to get that wall reading?
I said it somewhere else recently, but it bears repeating. One of my dedicated crypto mining rigs pulls about 650W from the wall. Three video cards. It's being powered by a Seasonic X-1050, 80 Plus Gold. I have a 1kW Seasonic built Platinum I could put in there, but I haven't. Why? Because the Gold unit is actually within 1% as efficient at the same load level.
The other dedicated mining rig is running an AX1500i. Titanium. That one pulls 700W out of the PSU, currently running five cards. It's about 93.5% efficient at that power level. That's when you start seeing real gains over 80 Plus Gold, because Titanium requires high efficiency over a broader range. It starts at 10% load levels, where everything else starts at 20%. Of course, Titanium costs big bucks right now... we're still talking about years to make up the difference in power cost savings. Especially when both Titanium units on the market are 1500-1600W monsters retailing for over $400 USD each.
Long story short, Gold or Platinum really doesn't matter that much right now. It's really a toss-up when it comes to purchase price vs. power bill cost savings and build quality, as long as you're looking at a half decent OEM to begin with.