Do You Have the Power? Part 2

19 Feb, 2015 By: Alex Herrera

Herrera on Hardware: Don't make an aftermarket upgrade; choose the right power supply unit for your workstation configuration from the get-go.

Editor's note: Read "Do You Have the Power? Part 1" here.

It may not epitomize cutting-edge technology for CAD computing, but there's more to the role and selection of a workstation-caliber power supply unit (PSU) than meets the eye. While it's not directly responsible for delivering the computation and visualization throughput modern CAD workflows demand, as your workstation's power plant, it's what enables all those high-performance components under the hood — the central processing units (CPU), graphics processing units (GPUs), memory, and storage — to get their job done.

PSU Technology and Design Continue to Advance

Workstation vendors in particular have been improving the PSU on two primary fronts: efficiency and serviceability. Typically measured in how much DC power is output as a percentage of how much AC power is input, PSU efficiency tends to vary by load (i.e., current draw, where a mid-range load tends to be more efficient than a very low load or a load approaching the PSU's rated capacity). A rating program jointly funded by electric utilities, called 80 PLUS, has become the de facto standard for assessing and branding power supply efficiency.

% of rated load










80 PLUS Bronze





80 PLUS Silver





80 PLUS Gold





80 PLUS Platinum





80 PLUS Titanium





Power efficiency levels, as determined by the 80 PLUS rating program. Data courtesy of

The PSU will almost always be emblazoned with the logo corresponding to the 80 PLUS level it achieved. And if you want to be sure of what you're getting when shopping, refer to the online datasheet or the vendor's custom system configuration.


Virtually every workstation-caliber PSU today is stamped with its 80 PLUS efficiency rating.

For those looking to improve the power efficiency of computers, PSUs haven't historically been the most cooperative of components. Granted, converting 110 AC volts to the 5 and 12 DC volts the machine's digital components want to see isn't a trivial task. But as a major consumer of the power it's supposed to be supplying, the PSU itself became a primary focus for system designers intent on effective power reduction. Consider the frustration of chip and motherboard designers who bend over backward to trim a watt here and there, only to see a system's inefficient PSU waste 50 watts on the power conversion.

In the past decade, power efficiency has moved front and center in computer design as a whole, and PSUs have been whipped into better shape as a result. Today, the workstation industry and its customers can treat 80% efficiency as the bottom end of the spectrum. Even cost-effective PSUs can deliver that number, so there's no reason for a professional user to compromise on anything less. Furthermore, more advanced PSUs (especially those that are rated for higher maximum output) can deliver better than 85 and 90% and have become readily available options on workstations from top-tier vendors such as HP, Dell, and Lenovo.

Superior PSU efficiency offers the obvious advantage of lowering electricity demand and therefore bills, but the benefits don't end there. A more efficient PSU generates less heat, thereby reducing the system's overall thermal footprint, and that's always a good thing. Hotter components are inherently more prone to failure; cooler systems are more reliable. And the higher the workstation's thermal output, the hotter your office or workspace may become — not to mention noisier, as more cooling fans spin faster to combat the increased heat.

Modular, Tool-less PSUs Simplify Access

The mechanical and package design of PSUs continues to advance as well, particularly with workstation models marketed for high-end CAD productivity. The modular PSU, which can be easily pulled in and out of a chassis with no tools required, has been a hot design trend as of late.

First introduced in the company's inaugural Z workstations in 2009, modular PSUs are increasingly common across the industry's workstation models, including HP's top-end Z800 series, along with Lenovo's midrange P700 and high-end P900. Dell has been particularly aggressive with modular PSU design, not only making the option available across the entire Precision workstation line — down to the entry-level Tower 5810 — but making access external as well (so there's no need to open the chassis to access it).

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About the Author: Alex Herrera

Alex Herrera

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