AMD Ryzen 9 9900X3D Review: 3D V-Cache's Middle Child Needs a Price Cut

AMD Ryzen 9 9900X3D Power Consumption and Efficiency

We measure CPU power consumption metrics directly at the EPS12V connector because software-based measurements can be 'cheated' by motherboard vendors. This approach gives us the best visibility into accurate power consumption metrics but differs from results gathered from the wall plug (which include full system power) and software-based measurements. Our measurements represent the power the CPU power delivery subsystem consumes directly from the PSU, but it doesn't account for VRM efficiencies (roughly 10% on high-end motherboards).

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The Ryzen 9 9900X3D isn't as power hungry as its larger sibling, the 9950X3D. The chip peaked at 181W but hovered in the 160–170 Watts range during many of the workloads.

As expected, the Core i9-14900K is an egregious power guzzler, sucking down up to 383W during the Blender workload, but it does deliver more overall performance in our suite. The Core Ultra 9 285K is more miserly than the 14900K, but it peaks at 325W, showing it can also have a voracious appetite.

As expected, we see a disproportionately large increase in power consumption for slim performance gains when we kick on the 9900X3D’s Precision Boost Overdrive (PBO) feature. PBO isn’t worth the extra power consumption for gaming, where it delivers imperceptible benefits, but it's far more useful for those focused on productivity work or heavy multi-tasking.

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We measure our standard idle power metrics after a lengthy time of inactivity with all background tasks terminated. The Ryzen processors consume more idle power than comparable Intel models, largely due to the need to keep the large I/O Die powered despite low-load conditions. Here, the Core Ultra processors bring idle power consumption to new lows, with the 285K consuming only 8W. In contrast, the Ryzen 9 9900X3D pulls 22W at idle, a notable disadvantage.

Most PCs rarely truly idle; users might leave various applications open on the desktop. There's also an 'active idle' use case wherein the user does a low-load activity, such as browsing the web or watching a YouTube video. To model this behavior, we created an active idle test (second slide) with two browser windows open (one with two tabs idling on a website and another window with a 4K YouTube video stream playing). We measure this level of activity across a 15-minute timespan.

We measured the Core Ultra 9 285K at 20W under these conditions, but the Ryzen 9 9900X3D consumed 37W. While we can see that the 9900X3D has improved compared to the previous-gen Ryzen 7000X3D models, this is still a significantly higher amount of active idle power draw than the Intel chips.

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The watts-per-FPS chart quantifies power efficiency during an x265 HandBrake workload. The 9900X3D is near the top of the list with strong power efficiency metrics. We see a similar trend in the other efficiency metrics.

The last three slides take a slightly different look at power consumption by plotting the cumulative energy required for an x265 HandBrake, Linpack, and Blender workload. We plot this 'task energy' value in Kilojoules on the left side of the chart, with performance charted on the x-axis.

These workloads consist of a fixed amount of work, so we can plot the task energy against the performance during the job (bottom axis), thus generating a useful power chart. Faster compute performance and lower task energy are ideal. That means processors closest to the bottom right corner of the chart are the best.

The Ryzen 9 9900X3D falls into the sweet spot of performance and power efficiency in these charts, with a particularly strong showing in Blender. Meanwhile, the 285K and other Arrow Lake chips greatly improve over their 14th-Gen predecessors.

AMD Ryzen 9 9900X3D Test Setup

We tested with the latest version of Microsoft Windows 24H2 (22631) and have updated all drivers, BIOSes, and applications to the latest versions. To speed up the testing process, we use XMP/EXPO as the default memory profile for all tested configurations. The memory speeds used for each chip are shown in the table below.

We tested the Ryzen 9 9900X3D in standard stock trim and with the auto-overclocking Precision Boost Overdrive (PBO) feature enabled. We used the 'advanced' and 'motherboard' power settings for the PBO configuration with a 10X scalar and 200 MHz clock adjustment. We also dialed in a -15 all-core Curve Optimizer offset.

We used lifted power limits for the Intel processors, which results in higher power consumption and heat, but you get faster performance in exchange.

We use the Nvidia GeForce RTX 5090 Founders Edition for our game testing. For the sake of expediency, our power measurements in the gaming section are gathered by polling the motherboard sensor loop, while the metrics in the dedicated power testing section use more precise direct measurements at the EPS12V connector.

Microsoft has advised gamers to turn off several security features to boost gaming performance. For maximum performance, we disabled Virtualization Based Security (VBS) on all systems. Be aware that, due to hardware acceleration, some processor architectures handle virtualization better than others. This can provide a performance advantage when gaming with VBS enabled, but we haven't observed meaningful differences in our testing.

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