The latest high-end CPUs are here, and they are certainly fast, but in this video, we’re going to intentionally limit their power to see how much performance we can get out of them using ECO mode. We will still show you results from these chips running at stock settings, as well as some overclocking options if you’re interested, but our main focus will be on ECO mode.
Let’s start with a quick explanation of ECO mode. Introduced with the last generation of AMD processors, ECO mode essentially works in the opposite way of PBO. Its goal is to restrict power consumption, which means the CPU runs at lower speeds and cooler temperatures. This naturally reduces performance, but not as much as you might think. For example, the 9950X CPU at stock settings can easily reach 180W under full load, but with 65W ECO mode enabled, it maxes out around 90W, similar to the 65W TDP chips like the 9600X and 9700X.
To dive deeper into the setup before we get to the benchmarks, take a look at this graph. At the top, you'll see the 9950X at stock settings, followed by the 9700X with PBO and Curve Optimizer enabled — arguably one of the best ways to overclock this CPU for maximum performance. By the way, we have a video on how to do this; you can find the link in the description below.
At the bottom of the graph, you'll find a few CPUs: the 9700X at stock settings, along with the 9900X and 9950X running in ECO mode.
Looking at the frequency graph, there’s a noticeable difference between the overclocked 8-core 9700X and the 16-core 9950X in ECO mode. On average, there's a 2.1 GHz gap between the two, which is nearly half the speed.
When we compare temperatures, the difference is equally striking. The 9900X and 9950X CPUs hover around 55 degrees Celsius, while the overclocked 9700X is pinned at its TJMAX of 95 degrees. Even at stock this chip is about 8 degrees hotter.
From this, it’s clear that the higher-core chips are significantly limited—they're running much slower, cooler, and consuming about the same amount of power as an 8-core chip at stock settings.
Keep this in mind as we move into the benchmarks, starting with Vray. This benchmark relies on maximum all-core performance, and we see that both ECO-mode chips fall in the middle of the pack, with the overclocked 9700X matching the performance of the 9900X using ECO mode. However, when comparing the 9700X at stock with EXPO enabled to the 9900X with EXPO and ECO mode, there's a 21% performance gap. The difference jumps to 51% when compared to the 9950X. If you compare the 9950X at stock to its ECO mode, you’re leaving 44% of the performance on the table—a significant margin. Overclocking the 9950X increases the gap to 60%, but at that point, it’s no longer the power-efficient chip we’re aiming for.
Moving on to the next test, the triple Blender Render. Here both ECO chips are yet again in the middle of the stack, with similar ratios as before. More cores in an all-core workload naturally lead to better performance—this is to be expected.
To further illustrate this, take a look at the 7-Zip multi-core score. The 9900X in ECO mode outperforms the overclocked 9700X by 16% in compression and 14% in decompression.
When we switch to the single-core version of the same test, the performance gap between all the scores narrows considerably, making the differences less significant. While heavily overclocked and optimized setups do perform better, the best results come from using PBO + Curve Optimiser.
The next test, the OCCT RAM test, presents an interesting scenario. There’s a noticeable gap between the lower-end 6- and 8-core chips and the higher-end 12- and 16-core chips. In this case, ECO mode doesn’t make much of an impact compared to the architectural differences, with a gap of around 20% between the lower and higher-end chips.
Lastly, we ran a quick gaming test using Shadow of the Tomb Raider at 1080p with a Radeon 6900XT graphics card. At these settings, we observed that moving from the 9900X at stock to the overclocked 9950X yielded up to a 12% increase in average FPS. However, the results remained consistent even with ECO mode enabled. This is because, in many games, the CPU isn’t running at 100% on all cores; instead, only a few cores are utilized, and even at full speed, they stay below the 90-Watt threshold that ECO mode operates within, which makes for an interesting conclusion.
When I started working on this project, I was quite sceptical. Halving the power envelope on these CPUs seemed extreme, and I expected to see rather poor results. However, in many cases, we saw more than adequate performance even at the lower power consumption levels. While it might seem odd for the average consumer to buy a high-end CPU and run it in ECO mode, there are scenarios where you might want a low-power, low-heat CPU that still delivers excellent single-core or even multi-core performance. This also means a quieter cooler, and if needed, this can always be unlocked to go full ham. What do you guys think – does anyone actually use ECO mode? Let us know in the comments below.