AMD now sells two eight-core X3D chips that look almost identical on paper. The Ryzen 7 9850X3D is the newer one, and it is usually a little faster and a little more expensive. For a UK gaming PC, the question is whether that gap is worth paying for.
Forge PC hasn't tested either processor. Official specifications come from AMD's product pages. Performance, power and value conclusions are from Tom's Hardware's 9850X3D review, its direct 9800X3D comparison, and a later Precision Boost Overdrive retest, all credited below. UK prices are the lowest new listings on SpecPrice, updated at 07:57 GMT on 13 November 2026, and are approximate.
What's actually different
| Ryzen 7 9800X3D | Ryzen 7 9850X3D |
|---|
Cores / threads | 8 / 16 | 8 / 16 |
Base clock | 4.7GHz | 4.7GHz |
Max boost clock | Up to 5.2GHz | Up to 5.6GHz |
L2 cache | 8MB | 8MB |
L3 cache | 96MB | 96MB |
Default TDP | 120W | 120W |
Socket | AM5 | AM5 |
Launch date (AMD) | 7 November 2024 | 29 January 2026 |
Lowest UK price, 13 Nov 2026 | £349.98 | £369.98 |
AMD's official pages show the same core count, cache and 120W default TDP. Tom's Hardware puts it simply: clock speed is the differentiator. The 9850X3D's official boost is 400MHz higher. Both chips are unlocked and support Precision Boost Overdrive and EXPO memory on AM5, so they fit the same boards as each other and as other current Ryzen desktop chips. Our AM5 motherboard guide covers the platforms.
What Tom's Hardware measured in games
In its head-to-head, Tom's Hardware's 16-game 1080p geomean had the 9850X3D at 211.2fps and the 9800X3D at 204.6fps, a 3.2 per cent lead. The review of the 9850X3D describes a similar 3.3 per cent edge and calls it "the world's fastest gaming processor, if only by 3.3%."
That lead was not even in every title. Tom's Hardware says the two chips were within the margin of error in several games, including Starfield, Monster Hunter Wilds, DOOM: The Dark Ages and Cyberpunk 2077, with larger gaps in others — for example 6.2 per cent in Flight Simulator 24 in the faceoff. 1 per cent lows in that 16-game average favoured the 9850X3D by 3.52 per cent (147fps versus 142fps).
The more striking difference was power. In the same faceoff, Tom's Hardware recorded about 106W for the 9850X3D in games versus 81.4W for the 9800X3D, which it described as roughly 30 per cent more power for that 3.2 per cent performance gain. Both chips share a 120W official TDP; the extra draw is how they behave in those tests, not a change to the rated figure. A good tower cooler is still enough for either chip; see our CPU cooler guide.
Productivity and clocks
Because the two chips have the same core count, heavily multi-threaded work is not where the 9850X3D pulls ahead. Tom's Hardware found a clearer gap in lightly-threaded tests: a 6.5 per cent lead in its single-threaded geomean (a score of 259 versus 243), and nearly 7 per cent in Cinebench 2024's single-core test. If most of your time is in those lighter tasks as well as games, the newer chip's extra boost is more visible than it is in a game average.
A later Tom's Hardware retest is awkward for the 9850X3D's marketing. With Precision Boost Overdrive enabled and a +200MHz boost override on both chips, the 9800X3D gained 2.7 per cent over its stock game average and ended up only 0.6 per cent behind a stock 9850X3D. The 9850X3D itself gained just 0.9 per cent with the same override. That is optional tuning, not stock behaviour, but it is one reason reviewers keep pointing people back to the older chip.
Price and which one to buy
On 13 November the UK gap was £20, or about 6 per cent: £349.98 versus £369.98. That is a smaller premium than some earlier US comparisons, but the performance gap is still only a few per cent in Tom's Hardware's game average.
Buy the 9800X3D if you want the usual "best gaming CPU" recommendation and you'd rather keep £20 and use a little less power. It remains the better value in Tom's Hardware's comparison, and it is the chip we would default to in an AM5 gaming build, including the systems in our CPU guide and complete PC guides.
Buy the 9850X3D if you want the fastest out-of-the-box gaming chip and don't want to enable PBO, or if lightly-threaded work matters enough to pay for the higher official boost. Don't buy it as an upgrade from a 9800X3D you already own; Tom's Hardware is clear that this is not that sort of step.
Both chips need DDR5 and an AM5 board, which is where most of a new platform's cost now sits. If you are still choosing a socket, our November market roundup and upgrade guide set out why AM5 is the usual new-build choice.
Our verdict
The Ryzen 7 9800X3D is the one to buy for most people. Officially, the 9850X3D only adds a higher boost clock on the same eight-core, 96MB L3, 120W design, and Tom's Hardware measured about 3 per cent more average gaming performance for roughly 30 per cent more power in games, at a £20 premium in the UK on 13 November 2026. Pay the extra if you want the newer chip's out-of-the-box clocks and a small lead in lighter work. Otherwise, put the money towards memory or the graphics card — they will make a bigger difference to the finished PC.
