#52: The Power of the Cloud

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Being shown around a modern datacenter is a pretty awesome experience. The huge rooms full of servers, networking gear and storage can be reminiscent of that last scene in Raiders of the Lost Ark. Dig a little deeper, though, and it’s the power systems that are truly jaw-dropping; how much power the DC uses when it’s running and what to do if the power supply goes away is a big part of building these operations.

At one point, Microsoft used huge Caterpillar diesel generators, each of which could generate several megawatts and was kept ready and waiting by continually pumping hot oil inside, so the machine could be started and running at full tilt in a fraction of a second in the event of power failure. Moves are afoot to use hydrogen fuel cells or other means of storing and generating backup power.

AI and Datacenter boom

As much traditional computing has moved into the cloud over the last decade or two, and faster and more mobile internet access drives end-user demand, datacenters have been getting bigger and more numerous. They almost can’t build them fast enough. About 1/3 of all worldwide DCs are in the US, and together they soak up about 6% of all electricity.

Datacentres worldwide used about 460 TWh of electricity in 2022; that’s 460 billion KWh, or enough to run 35 trillion lightbulbs continuously – about 4,300, 24×7, for each person on the planet. That’s quite a lot of power. Expect that amount to double by 2026. Google and Microsoft reportedly consumed 24TWh each in 2023.

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[source – Electricity 2024 – Analysis and forecast to 2026]
https://iea.blob.core.windows.net/assets/6b2fd954-2017-408e-bf08-952fdd62118a/Electricity2024-Analysisandforecastto2026.pdf

Generative AI is VERY power hungry: estimates vary but research showed that generating one image used as much power as over 500 smartphone charges, averaging around 3KWh per image. Better make sure your ChatGPT / Copilot / Microsoft Designer usage is worthwhile and not just creating stupid images of cats and dogs.

To put the commensurate CO2 output into context, however, 1,000 of such images would be the equivalent emissions of driving a car for 4.1 miles. It’s thought that Generative AI on its own could well consume 100TWh or more by 2027.

DC providers are also looking for ways to ensure they can get enough power into the datacenter – Microsoft has even committed to restarting one of the Three Mile Island nuclear reactors and buying all of its power for 20 years. A nod to the old commitment of being carbon negative by 2030, perhaps, but the massive DC expansion to fuel demand for AI makes achieving that target seem increasingly unlikely.

Maybe new governmental administrations will incentivize clean power and reward efficiency?

Local PC power usage

There is something of a dichotomy in power usage on a local computer, especially if it’s powered from the wall rather than using a battery. You want to buy the highest performing, most feature-laden machine you can afford, so (apart from preserving battery life) why would you deliberately knobble its performance to save power? Like buying a Ferrari and driving everywhere at 20mph.

Some quick wins, especially on laptops, could be to reduce the brightness of the screen and use Dark Mode. Check the Power settings on your PC for recommendations on how to lower its energy use. Reduce the number of background apps and trim the ones which start automatically.

If you have an Intel-powered computer (PC, Mac or Linux), they have a free power usage gadget which might give you some idea about the total power consumption of your system, though doesn’t really shed much light as to what’s making it do what it’s doing…

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You could try firing up Task Manager (CTRL+SHIFT+ESC) and adding a couple of columns to its default view (right-click on the column headings); useful to know which apps or processes are causing the power usage to shoot up, but devoid of actual numbers for the more data-obsessed.

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Edge browser has an Efficiency mode – click the … settings menu in the top right and look under Browser essentials.

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If you need more data on overall system performance, try GPU-Z – it gives detailed stats on the Graphics Processing Unit and other main components of your system, including current, maximum / minimum / average power consumption …

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In the screenshot above, the Power Consumption (%) shows how much of the graphics board’s maximum power consumption is currently being used. A similar utility, CPU-Z, can give data about the TDP of the main CPU and how it’s doing too.

Tip o’ the Week 433 – You can have the power

clip_image001With modern hardware and Windows 10, there is a great deal of flexibility in the way power (in the sense of AC/DC as opposed to Power Users) is managed.

As PC systems evolved over time, and Windows got reliable to the extent that you don’t need to reboot every day or even every week (Windows 7, realistically), the needs of power management also changed as the shift from mains-powered desktop to Lithium-Ion battery laptops gathered pace.

Sleep states defined what goes on under the covers in as a PC goes into a different power mode – whether that’s automatic (because of timing, or because the battery level gets to a particular point) or if the user chooses to sleep/hibernate, hits the power button, closes the laptop lid etc.

Most PCs could go into a low-power (S3) standby state, where the CPU was shut down but the contents of memory were preserved (still consuming power, but a lot less of it), so the machine can be woken up quickly and carry on as before. After some period in standby or at a point where the battery was about to run out, the PC might even wake up and dump the memory contents to a file on disk, then shut down completely (called hibernating), meaning a subsequent wake-up would take a few seconds longer as it would need to resume from hibernate, since the contents of that huge memory file will be read back in before continuing.

Windows 8 introduced the idea of “Connected Standby”, meaning that even when a machine was in a low-power state – to all intents, asleep, but with the CPU still able to run in a restricted manner – the system can maintain a wireless connection that means apps could remain up to date. This was a feature that only applied to modern/Store apps, allowing for synchronising contents in the background while the PC was asleep, so that when it wakes up, the app data and live tiles on the Start screen would be up to date.

As both hardware and software platforms have improved, the connected standby idea morphed into Windows 10’s “modern standby”. ToW 335 talked about managing battery states in Windows 10, and briefly discussed using a powerful tool to tweak the way your PC handles standby states.

Powercfg is a command line tool, run from an elevated command prompt (ie clip_image003one with admin privileges – press WindowsKey+R, type cmd, then crucially, press CTRL+SHIFT+ENTER to ensure the command line is entered with the right level of privilege). If you don’t see “Administrator” in the title bar of your resulting command windows, you ain’t an admin, buster.

To check and see what power modes your PC can handle, try running powercfg /a; a more traditional, ACPI desktop will clip_image005probably support S3 and Hibernate modes, but a modern laptop will likely be able to operate in Standby (S0 low power idle) – that’s “modern standby”.

You can get some detailed reporting on how your PC is behaving, by using powercfg with one of the following command line arguments: /energy, /batteryreport, /sleepstudy, /srumutil, /systemsleepdiagnostics or /systempowerreport.

SKYPE FOR SIGN OUT, OUTLOOK FOR DISCONNECT

Now, one side-effect of this S0 low power mode is that Windows 10 PCs will likely enter that mode shortly after the screen is locked (via timeout or by WindowsKey+L). Non-modern apps (ie Win32/x64 apps like Outlook, Skype for Business etc) won’t know how to deal with this effectively disconnected state, and will drop their connection.

This means that when you unlock a plugged-in laptop after being away for a while, you’ll see that Skype for Business is signed out, and Outlook might tell you it’s lost the connection to the server (and then immediately re-connects). If you find this annoying and would rather lengthen the time that elapses when your machine is plugged in, before it goes to connected standby mode, then powercfg to the rescue!

From an elevated command prompt, run:

  • Powercfg /setacvalueindex scheme_current sub_video videoconlock 3600
  • Powercfg /setactive scheme_current

Using the flag /setdcvalueindex instead will tweak the behaviour when on battery only. The value in the first command is the number of seconds before the screen will timeout when locked, so substitute 3600 seconds (ie 60 minutes) for a value of your choice. For further details of what Powercfg can do, see here.