Intel Shares Potential Fix for High Idle Power Consumption on Arc GPUs

[harlan4096]

Seeking parity with the competition
 

At the launch of Intel's Arc A770 and Arc A750 graphics cards, reviewers noticed a strange pattern: Intel cards were pulling significantly higher power at idle than comparable AMD and Nvidia graphics cards. Intel revealed in a blog post (opens in new tab) today that it managed to hit two rabbits with one stone: it recognized higher than expected idle power consumption affecting its Arc series of graphics cards, while simultaneously offering a fix. One possible issue for some users, however, is that applying the fix requires fiddling with motherboard BIOS settings — something not all users are comfortable doing. 

Intel's guide requires that users enter their BIOS settings to change the PCI-Express-related power options. Namely, users should change the Active-state power management (ASPM) setting on their motherboards, a technology that allows PCIe devices to enter lowered power-states when they're not in heavy use. After a romp through the BIOS, Intel directs users to also change some relevant settings within Windows' power options.

First, users should make sure that their OS can control PCIe power states by changing their BIOS' "Native ASPM" setting to "Enabled". Then, Intel says users should enable "PCI Express root port ASPM" and select "L1 Substates" from the subsequent options. The terms used to describe these settings may vary according to manufacturer, so make sure to read your motherboards' manual if you find yourself at a loss.

And that's assuming your motherboard even exposes the related settings. After poring through the BIOS settings on two different Intel platforms (one an older i9-9900K with MSI MEG Z390 Ace motherboard and the other a newer Z690 system with an MSI Z690-A DDR4 WiFi paired with Intel's 12900K CPU), no such options were to be found. The Z390 board was already using the latest BIOS, but we checked and found an updated BIOS for the Z690 board. Flashing the BIOS exposed the necessary options, thankfully, though there was no fix for the older board.

Your mileage may vary depending on the motherboard, how old it is, and its manufacturer. Some boards may even have these settings active by default.

This is the relevant setting you should change under Windows' Power Settings menu. (Image credit: Intel)After you've fiddled with your BIOS, it's time to boot up Windows, and you'll still likely see abnormally high idle power consumption on your Arc card. You now need to navigate to Windows' Power settings: simply search for "Power" on Windows' search bar, and then select the option "Edit Power Plan."

While editing your preferred Power Plan, expand the "Change advanced power settings" option; look for the "PCI Express" setting, and click its "+" button to the left to expand additional options, and set the "Link State Power Management" setting to "Maximum power savings." Simple enough in theory; how's it work in practice?

After testing Intel's Arc A750 and Arc A770 power consumption at idle with and without Intel's fix applied, we can say there was a significant difference in power consumption... on one of the cards. For the Arc A750, Intel's fix reduced idle power consumption by over 50%: its average idle power draw was reduced to 15.5 W, compared to 37.3 W with standard BIOS and Windows power settings.

As for the A770, it strangely showcased the same average power consumption before and after the fix. We rebooted (multiple times), swapped cards, sacrificed a virgin tube of thermal past... all for naught. We're still poking at it, but it's something to keep in mind. Perhaps a future driver update will help out.

Intel Arc A770 Idle Power Consumption (Chip Power) Before BIOS Changes (Avg)After BIOS Changes (Avg)Arc A77038.938.9Arc A75037.3 W15.5 WOur own review of Intel's Arc A770 And Arc A750 graphics cards showed that Intel delivered capable products towards the mainstream gaming crowd. The company achieved that with lesser power efficiency against comparable AMD and Nvidia designs, however. Averaging an 8-game benchmark, the Arc A770 delivered 11% less performance than Nvidia's RTX 3060 Ti while consuming as much as the RTX 3070. That may not look like much - and it isn't, in the grand scheme of things.

Except that in this day and age where electricity prices keep climbing and every consumer grapples with higher costs of living, higher power consumption does translate to higher power bills. Cutting on power consumption inefficiencies thus becomes more important than ever. An average of 22 W difference between the Intel fix being applied and not may not look like much, but depending on your local electrical power pricing and whether or not you keep your PC on at all times, you could be saving ~30$ per year.

Interestingly, Intel says that its Arc graphics cards were designed to work with the latest technologies available, indicating that users whose motherboards don't have ASPM enabled are behind the technological curve for its graphics cards. It's an interesting statement; ASPM was introduced as part of the PCI Express 2.0 specification, so we're not exactly on the cutting edge of power-saving features. 

Intel's statement also rings somewhat hollow when we consider that both AMD and Nvidia manage to achieve lower idle power consumption for graphics cards that directly compete with Intel's Arc 7-series - without any need for a BIOS intervention on the users' part. In fact, Nvidia's latest powerhouse, the RTX 4090, can consume just 4.5 W on average when at idle. 

At the same time, Intel says that it will include fixes for this high idle power consumption in later architectures. The nature of the fix and Intel's own statements indicate that this is something the company can't fix solely through its drivers. Perhaps these are all elements of Arc Alchemist being the first discrete GPU architecture from Intel. We'll see what happens with subsequent iterations.
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