We talk a lot about socket changes, the arrival of DDR5, but the changes affecting our power supplies are not anecdotal at all. The new ATX 3.0 standard is going to change a lot. PCIe Gen 5.0 (12VHPWR) connectors that will power the next generation of GPUs are just the visible part of these changes.
Our power supplies are undergoing a major overhaul with ATX 3.0
For nearly 20 years, the standard for PC power supplies has hardly changed. The arrival of the ATX 3.0 standard is the first real upgrade since 2003. It’s almost certain that your refrigerators, your cars or even your bicycles have changed more in recent years than the power supply of your PC.
computer world held an interview with Intel’s platform power specialist, Stephen Eastman. He goes back to one of the causes of the problems on power supplies that the ATX 3.0 standard has to deal with: voltage spikes. The problem is especially evident with graphics cards. It is estimated that a graphics card has the capacity to exceed the maximum power by 3 times. To make it simple and In concrete terms, this means that if your card has a TGP of 400 Watts, the latter can generate voltage peaks of up to 1200 Watts! What should you be concerned about when you think about that? the next generation of Nvidia needs up to 600 Watts of power, which would indicate peaks of up to 1,800 watts.
GPU on PCIe Gen 5.0: another connector… But not only
These power spikes already exist on your current PCs and are generally undetectable because they last a few thousandths of a second. But with the increase in TGP, these power spikes lead to breakdowns and outages more regularly.
This implies major changes in the design of the power supply that go beyond the simple switch of connectors. And this is a serious topic, as it poses the problem of “adapters” that can be added to current power supplies (ATX 2.0). On the new 12VHPWR connectora smaller connector attached to it carries additional signaling that tells the graphics card how much power is available from the power supply.
With ATX 3.0, these voltage spikes are managed so GPU vendors finally have limits to follow. A board manufacturer now knows that they are allowed to push 200% of the maximum power of the power supplies for 100 microseconds or 120% of the maximum power of the PSU for 100 milliseconds. This allowed us to significantly increase the reliability and stability of PCs. Indeed, we open the door to a modulation of the available power according to the “dialogue” with the graphics card (and probably the rest of the PC).
So you have understood that the switch to the ATX 3.0 standard is inevitable… And here again it will lead to a price increase.
In summary, here are the few words from the exchange with Intel on PC World:
To overcome these extremely short power surges, a power supply must be designed with enough additional capacitors to prevent the system from losing power and possibly crashing the PC. According to Intel’s estimates, a 300 watt GPU on a well-designed ATX 3.0 could be supported with a 750 watt power supply with 300 watts for the CPU and another 150 watts for the rest of the hardware in the box.
If you’re trying to modify an existing ATX 2.X power supply to run that same 300-watt GPU, you might need a 1,100-watt power supply to support the GPU, CPU, and power outages, Intel believes. This will likely depend on the older PSU design and how often that GPU will make those powerful excursions.
