AMD Ryzen 9 9900X Review

AMD has been staggering its launches with the launch of its Ryzen 9000 processors, with the more affordable Ryzen 5 9600X and Ryzen 7 9700X hitting shelves last week. Now it’s time for the high-end chips, with the $499 Ryzen 9 9900X the first to arrive.

I’ll start by admitting my bias towards AMD’s 12-core processors, as I really appreciate the Ryzen 9 7900X and 7900. The latter was a solid workhorse, powering my main AM5 test PC, running games and content creation apps with ease. Sure, the full-blown 16-core models top the charts when it comes to multi-threaded performance, and you can’t beat the X3D chips with their extra L3 cache for gaming, but the Ryzen 9 7900 really is a fantastic all-around processor.

I was curious to see what the Zen 5 update to one of my favorite chips would look like, but after reviewing the 9600X and 9700X I realized I would have to lower my expectations a bit. Little did I know at the time how much I would have to lower my hopes.

The Ryzen 9 9900X consists of three chiplets under the heat spreader — two CCDs (Core Complex Dies), each with six cores and 12 threads, and a single IOD (Input/Output Die). This is exactly the same as the previous Ryzen 9 7900X model, but there are some further changes, beyond the obvious improvements to AMD’s Zen 5 architecture.

While the 7900X has a base clock of 4.7GHz and a TDP of 170W, the up-to-date 9900X has a base clock of 4.4GHz and a much lower TDP of just 120W. The boost clock is the same for both chips (5.6GHz), so the up-to-date model has a smaller power budget, allowing it to maintain boost clocks under ponderous loads.

After installing the chip, the first thing I checked was the idle behavior, as I had noticed this on the 9600X and 9700X as something unusual compared to AMD’s data. Again, my Windows setup and Asus ROG Crosshair X670E Hero motherboard, using the AMD-supplied BIOS 2201, resulted in increased idle power consumption, typically around 40W.

For cooling, I used an Asus ROG Strix LC III 360mm AIO liquid cooler and it had no problem with that – in fact, it was a good 10°C cooler than the 9600X, so the high idle power consumption wasn’t an issue. I suspect this will all be sorted out over time, although AMD has suggested that you employ the Balanced power profile in Windows. I’ve tried all of them and it made no difference.

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Either way, you’re here for the benchmarks, so let’s start with the good news. The Ryzen 9 9900X performs great in tests that mimic the CPU workloads experienced during content creation and other professional applications, such as rendering, file compression and decompression, and video editing.

If your PC is primarily used for productivity tasks, then the Ryzen 9 9900X’s quick performance and relatively low power consumption clearly make it a great choice for anyone considering the Zen 5 as a prosumer workstation. Well, there’s a massive caveat about Eco mode, though, which I’ll mention in a moment.

On the other hand, if you’re more of a PC gamer than a professional, the 9900X isn’t exactly ideal. Yes, it beats the 7900X in all of our gaming tests, but the advantage is very miniature — the exception being Metro Exodus Enhanced, which is very edgy when it comes to the platform it’s running on.

Compared to my beloved 65W Ryzen 9 7900, the Ryzen 9 9900X is quite disappointing, as it isn’t really that much faster. Only the Factorio benchmark showed a noticeable difference in processing.

The somewhat subdued gaming performance isn’t all that bad news though, as the raw data itself is fine – it’s certainly not leisurely in any of our game tests.

No, the really bad news is Eco Mode. One thing we, the PC Gamer team, liked about the Ryzen 7900X and its bigger brother, the Ryzen 9 7950X, was that you could enable Eco Mode in the BIOS, cut a lot of the TDP, but still have a great processor. Here, setting the 9900X to 65W resulted in a less than great processor.

In this mode, the Ryzen 9 9900X ran slower than the 7900 in games and apps that taxed all the cores of the chip, like Blender and Handbrake. And that’s despite all the changes to the Zen 5 architecture.

At first glance, it might not seem like it’s a power limitation, as the Ryzen 9 7900X and 7900 are 170W and 65W processors respectively, so there’s no obvious reason why the 9900X would have trouble stepping up from 120W to 65W.

However, the 9900X is clocked quite high, and I suspect that all the changes to the Zen 5 CCDs mean they need more power than their predecessors when it comes to maintaining performance under ponderous loads.

AMD could remedy this by offering an additional Eco mode, like it does with its 170W chips. With those chips, you can choose between 105W or 65W, but since the Ryzen 9 9900X is a 120W chip, you only get the 65W Eco option. With an 80W or 90W option, you might be fine, but it does make me a little worried about what the inevitable non-X version of the 9900 will look like.

If you’re an Intel user, seeing that the quick, multi-threaded chip doesn’t draw more than 162W in Cinebench—over 100W less power than the Core i7 14700K—might tempt you to switch platforms and buy the Ryzen 9 9900X. But there’s a caveat that’s more significant than the Eco Mode issue, and that’s the Ryzen 9 7900X. The up-to-date Zen 5 chip has an MSRP of $499, a nice $50 discount from the 7900X’s starting price, but you can get the latter for $359 on Amazon right now.

That makes the 9900X about 40% more exorbitant than the 7900X, but it’s certainly not 40% faster. The up-to-date chips will certainly become cheaper over time, and given the somewhat mixed reception to the Ryzen 9000 series, that could happen sooner than you think. However, as it stands, I can’t recommend the Ryzen 9 9900X — it’s not a bad processor at all, just disappointing for the price.