Introduction

AMD's Ryzen 9 7900 "Zen 4" desktop processor is a very interesting product from the company, for people who know what they want and want to save a little on the side. This 12-core/24-thread processor is part of an early-2023 refresh of the Ryzen 7000 series with a trio of 65 W "non-X" SKUs spanning the 7900, 7700 (our review), and 7600 (our review). The idea here is to offer certain power-efficient SKUs that square off against Intel's 65 W non-K 13th Gen Core processors that launched around the same time. With its Ryzen 7000-series, AMD made integrated graphics standard-issue, which means businesses that need desktops with CPU power and who don't want discrete graphics, can opt for any 7000-series processor SKU, just like they would with Intel.



The Ryzen 9 7900 is AMD's third 12-core "Zen 4" processor SKU, the others being the 7900X with a much higher 170 W TDP and the same standard "Zen 4" chiplets; and the enthusiast-segment Ryzen 9 7900X3D, which features 3D Vertical Cache on one of its two chiplets, to significantly boost gaming performance. Each of these SKUs has something going for it, for the Ryzen 9 7900 in this review, it's the tight power limits that make it fall into the 65 W category; coupled with a nice 140 W-capable Wraith Prism RGB cooling solution included in the box (something the 7900X and 7900X3D lack). The iGPU and boxed cooler complete the package for the 7900 to be picked up by business customers.

The Ryzen 9 7900, along with the rest of the Ryzen 7000-series desktop lineup, debuts the new "Zen 4" microarchitecture, which promises a roughly 15% IPC increase over the previous-generation Zen 3, on the backs of a redesigned Front End component, support for new instruction sets, and a larger 1 MB dedicated L2 cache per core. The architecture also introduces support for AVX512, VNNI, and certain AI neural-net building/training acceleration components on the core. A big chunk of the generational IPC uplift also comes from the switch to DDR5 memory. These processors only support DDR5, there's no backwards-compatibility with DDR4 (like on Intel Alder Lake and Raptor Lake). As of March 2023, DDR5 memory prices are definitely on a downward trend, and so businesses should find it easy to buy entry-level DDR5 memory kits in bulk.

The Ryzen 9 7900 ticks at a 3.70 GHz base frequency, with a 5.40 GHz maximum boost (compared to 5.60 GHz of the 7900X). The 7900 has much tighter power limits compared to the 7900X, which should affect its boosting headroom in highly parallelized workloads. For lightly threaded workloads like gaming, this should be less of a problem, which is why the processor has rather generous maximum boost frequencies.

When we first reviewed the 65 W Ryzen 7000-series, we only had the 6-core 7600 and 8-core 7700 to play with, which makes the 7900 a kind of oddity in AMD's lineup. To find its ideal use-cases would be an interesting adventure, especially given its price of $430, which puts it roughly on par with the Core i7-13700K, and $20 cheaper than the 8-core Ryzen 7 7800X3D that the company plans to launch later this Spring in April. What's a bit surprising is that Ryzen 9 7900X currently sells for five dollars less than the 7900 non-X in this review, but you're not getting a CPU cooler with that.