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VIVID·REPAIRS/THE FIELD GUIDE/CPUUpdated 7 October 2026Prices live from Amazon UK

Best of · UK · Field of 10

Best CPUs Under £400

As an Amazon Associate we may earn from qualifying purchases. We have not handled these products. Everything below is judged on published specifications, the owner ratings on the UK listings and our own product reviews, and the ranking stays independent of what any of them pay.

As an Amazon Associate, we may earn from qualifying purchases. Our ranking is independent.
FIG. 01
Best CPUs Under £400: hero illustration

Illustration · Vivid RepairsCpu / 2026

Field10 ranked
Cheapest£139.99
Under £1503 of 10
Owner ratings read51,222
VIVID·REPAIRSThe verdict · cpus under £400 · UK · Processors
01 / 04

Our pick

AMD Ryzen ™ 7 9800X 3D Desktop Processor

AMD RYZEN ™ 7 9800X 3D Desktop Processor (8-core/16-thread, 104MB cache, up to 5.2 GHz max boost)

Why it’s our pick

  • Core count: 8
  • Rated 4.8 by 6,267 owners on the UK listing
  • £374.99 today, in a field that runs £139.99 to £374.99
  • Editorial score9.2 / 10
  • Owners4.8 from 6,267 ratings
£374.99Live price · checked today
Buy on Amazon£374.99

Amazon confirms the live price, seller, stock and delivery. Prices here are read from the live listing through the day; a pick Amazon cannot supply is marked as such, and where the list has one in stock it is offered.

Read the full review of this pick →

vividrepairs.co.uk / best-cpus-under-400Updated 7 October 2026 · Prices from the live Amazon UK listing
Not sure yet?The shortlist, argued pick by pick, starts here
§ Shortlist

The three worth arguing about

01
01 / 04

01 / Our pick

AMD Ryzen ™ 7 9800X 3D Desktop Processor

  • Best-in-class gaming performance at 1080p and 1440p, with measurable leads in average frame rates and 1% lows over all competing CPUs
  • 104MB of 3D V-Cache dramatically reduces cache-miss-related frame time spikes, producing noticeably smoother gameplay in CPU-sensitive titles
  • Zen 5 architecture delivers a meaningful IPC uplift over Zen 4, improving single-thread responsiveness in both games and everyday desktop workloads

Where it gives up

No integrated graphics, so a discrete GPU is mandatory even for basic display output during troubleshooting. Manual overclocking is partially restricted by AMD to protect the V-Cache SRAM, limiting tuning options compared to non-X3D chips.

Rated 4.8 by 6,267 owners. Our review scores it 9.2.

£374.99★★★★½ 4.8 · 6,267 ratingsBuy on Amazon£374.99

Amazon confirms the live price, seller, stock and delivery. · Read the full AMD Ryzen ™ 7 9800X 3D Desktop Processor review

02
01 / 08

02 / Best Value

AMD Ryzen 5 7600 Processor

  • Strong single-core boost to 5.1 GHz for excellent gaming performance
  • Efficient 65W TDP runs cool and quiet at stock settings
  • AM5 socket provides a long-term upgrade path

Where it gives up

Wraith Stealth cooler limits PBO headroom and is noisy under sustained load. AM5 motherboards carry a price premium over Intel LGA1700 alternatives.

Rated 4.7 by 3,277 owners. Our review scores it 8.5.

£158.59★★★★½ 4.7 · 3,277 ratingsBuy on Amazon£158.59

Amazon confirms the live price, seller, stock and delivery. · Read the full AMD Ryzen 5 7600 Processor review

03
01 / 08

03 / Best Premium

Intel® Core™ i7-14700K Desktop Processor 20 cores

  • Excellent single-core performance at 5.6 GHz boost for gaming
  • Strong multi-threaded throughput with 20 cores for content creation
  • Intel Quick Sync is genuinely useful for video encoding workloads

Where it gives up

High power draw under sustained load, needs serious cooling. LGA1700 is end-of-life with no CPU upgrade path.

Rated 4.6 by 1,373 owners. Our review scores it 8.0.

£345.97★★★★½ 4.6 · 1,373 ratingsBuy on Amazon£345.97

Amazon confirms the live price, seller, stock and delivery. · Read the full Intel® Core™ i7-14700K Desktop Processor 20 cores review

§ Also strong

Four that suit a different buyer

04Intel® Core™ Ultra 5 Desktop Processor 245KF 14 cores

Best Budget · Under £150

Intel® Core™ Ultra 5 Desktop Processor 245KF 14 cores

  • 5.2 GHz boost clock is competitive for gaming at this price point
  • PCIe 5.0 and DDR5 support future-proofs the platform
  • 14-core layout handles multitasking and light productivity well

Where it gives upNo integrated graphics means a discrete GPU is mandatory. No stock cooler included, adding to total build cost.

£139.99★★★★☆ 4.4 · 150 ratingsBuy on Amazon£139.99

Live price, checked today. Amazon confirms stock and delivery.

05AMD Ryzen 7 9700X Processor (8 Cores/16 Threads) 65W DTP

Best Build Quality

AMD Ryzen 7 9700X Processor (8 Cores/16 Threads) 65W DTP

  • Excellent single-core and gaming performance from Zen 5 architecture with real IPC gains over Zen 4
  • 65W TDP is genuinely impressive for this performance tier, resulting in cool, quiet operation and lower electricity costs
  • AM5 platform longevity with PCIe 5.0 support for both GPU and primary NVMe slot provides meaningful future-proofing

Where it gives upNo cooler included in the box, adding a required extra cost that first-time builders may not anticipate. Ryzen 7 9800X3D is a meaningfully faster gaming chip in cache-sensitive titles and is the better choice if gaming is the sole priority.

£269.99★★★★½ 4.8 · 2,697 ratingsBuy on Amazon£269.99

Live price, checked today. Amazon confirms stock and delivery.

06AMD Ryzen 9 9900X Processor

Runner-up

AMD Ryzen 9 9900X Processor

  • Zen 5 IPC improvements deliver real, measurable performance gains over Zen 4
  • 120W TDP is significantly more efficient than the 7900X it replaces
  • AM5 platform offers credible upgrade path through at least 2027

Where it gives upNo cooler included, and you genuinely need a decent one. Pure gamers can get similar performance cheaper with the Ryzen 7 9700X.

£329.99★★★★½ 4.8 · 1,727 ratingsBuy on Amazon£329.99

Live price, checked today. Amazon confirms stock and delivery.

07AMD Ryzen 5 5600X Processor

Runner-up

AMD Ryzen 5 5600X Processor

  • Excellent single-thread performance from Zen 3 architecture makes it highly capable in gaming workloads
  • Low 65W TDP keeps power draw, heat output, and electricity costs genuinely manageable
  • AM4 socket compatibility allows straightforward upgrades from existing Ryzen 2000 and 3000 series boards without replacing the motherboard

Where it gives upNo integrated graphics means a discrete GPU is absolutely required for any display output. Six cores can feel limiting under heavy sustained multi-threaded workloads such as video rendering or large software compilation.

£147.98★★★★½ 4.8 · 29,752 ratingsBuy on Amazon£147.98

Live price, checked today. Amazon confirms stock and delivery.

§ The rest

Shorter entries, simpler decisions

Every one of these still earns a place. Shorter entries because the decision is simpler: they do one job well and they tell you what they can’t do.

AMD Ryzen 5 8600G processor08

AMD Ryzen 5 8600G processor

Runner-upOur review scores it 8.5. ★★★★½ 4.7 from 1,282 ratings.

£159.00Live priceBuy on Amazon
Intel® Core™ i5-14400F Desktop Processor 10 cores09

Intel® Core™ i5-14400F Desktop Processor 10 cores

Runner-upOur review scores it 8.5. ★★★★½ 4.7 from 593 ratings.

£148.97Live priceBuy on Amazon
AMD Ryzen 5 9600X Processor10

AMD Ryzen 5 9600X Processor

Runner-upOur review scores it 9.0. ★★★★½ 4.9 from 4,104 ratings.

£160.97Live priceBuy on Amazon
§ Method

How we chose

The rules this ranking ran under, in plain sight: what we read, what we weighed and what no merchant can move.

How we picked

Our editors evaluated 10 Cpu options against the criteria readers actually weigh up: price, real-world performance, build quality, warranty, and UK availability. Picks lean toward what we'd recommend to a friend buying today, not specs-on-paper winners.

  • Editorial contextEditor notes from individual reviews, not press releases.
  • Live UK pricingRefreshed from Amazon UK twice daily.
  • No paid placementsAffiliate commission doesn't change what wins.
The full guideEverything behind the shortlist above: the spec sheet, the write-ups in full, our method and the verdict.

§ Editorial · The full guide · five proofs, nothing hidden

The Doubt Index.

The shortlist told you what we picked; this zone shows the working. Come in through whichever doubt you’re carrying, or read straight down; we’d rather you checked us than trusted us.

Proof A · The spec sheet

↑ All doubts

“Anyone can type a spec table.”

The spec sheet

Here’s the sheet the desk works from, kept deliberately factual. Every row is written to be checked against the retailer’s current listing, and you should check. The table scrolls sideways inside its own frame; the page underneath stays still.

Scroll sideways →10 rows · 5 columns · Prices swap to the live figure at render
ProductBest ForKey SpecPriceRating
AMD RYZEN ™ 7 9800X 3D Desktop ProcessorBest Overall Value8C/16T, 104MB cache, 5.2GHz£374.99★★★★½ (4.8)
AMD Ryzen 5 7600 ProcessorBest AM5 Starter6C/12T, 65W, cooler included£158.59★★★★½ (4.7)
Intel® Core™ i7-14700K Desktop ProcessorBest for Content Creators20 cores, 5.6GHz boost£345.97★★★★½ (4.6)
Intel® Core™ Ultra 5 Desktop Processor 245KFBest Budget14 cores, PCIe 5.0, 5.2GHz£139.99★★★★☆ (4.4)
AMD Ryzen 7 9700X ProcessorBest Efficient Eight-Core8C/16T, 65W, 5.5GHz£269.99★★★★½ (4.8)
AMD Ryzen 9 9900X ProcessorBest for Multitasking12C/24T, 120W, 5.6GHz£329.99★★★★½ (4.8)
AMD Ryzen 5 5600X ProcessorBest AM4 Upgrade6C/12T, 65W, cooler included£147.98★★★★½ (4.8)
AMD Ryzen 5 8600G processorBest for Beginners6C/12T, Radeon 760M iGPU£159.00★★★★½ (4.7)
Intel® Core™ i5-14400F Desktop ProcessorBest for Compact Builds10 cores, 65W, cooler included£148.97★★★★½ (4.7)
AMD Ryzen 5 9600X ProcessorBest Value Gaming6C/12T, 65W, 5.4GHz Zen 5£160.97★★★★½ (4.9)

Proof B · What the numbers mean

↑ All doubts

“I can read a spec sheet myself.”

What the numbers mean

You can, and you should. What follows is the part a sheet can’t do: the working between what these products have and what your desk actually needs, kept word for word.

Four hundred quid is a proper sweet spot for a processor. It's enough for the fastest gaming chip on the market, and low enough that you can spend a third of it and still build something that handles 1080p without breaking a sweat. So this guide to the Best CPUs Under £400 covers the full spread: AMD's cache-heavy X3D flagship, efficient Zen 5 six and eight-cores, Intel's core-packed 14th Gen chips, and a couple of budget AM4 and APU options that punch well above their money. We've ranked all 10 on published specs, verified Amazon UK owner ratings and our own research-led reviews. Prices move daily, so we've flagged brackets and the live shortcode does the rest.

Buying Guide: What to Look For

The first question isn't clock speed, it's socket. AM5 (the AMD 7000, 8000 and 9000 chips here) is supported through at least 2027, so a board bought now takes faster chips later. LGA1700 (the Intel 14th Gen i5 and i7) is done, and before first use those chips want a current motherboard BIOS: Intel’s 0x12B microcode addresses the voltage instability that affected 13th and 14th Gen processors, and LGA1851 (the Core Ultra 245KF) is newer but Intel's roadmap for it is shorter than AM5's. If you want to upgrade the CPU without swapping the motherboard in a couple of years, AMD's AM5 is the safer bet.

Then cores versus cache. For pure gaming, cache and single-thread speed matter more than raw core count, which is exactly why the eight-core 9800X3D with 104MB of cache beats 12 and 14-core chips in frame rates. For rendering, compiling or heavy streaming, core count wins, and that's where the 20-core i7-14700K and 12-core 9900X pull ahead. Six-core chips like the 9600X and 5600X are plenty for gaming but strain under sustained multi-thread loads.

Watch the hidden costs. Several chips here ship with no cooler: the 9800X3D, 9700X, 9900X, 9600X and both Intel K/KF parts. Budget £25 to £60 for one, more if the chip runs hot. Every AM5 chip needs DDR5, so an AM4 upgrader saves real money staying on the 5600X. The Intel 14th Gen chips take DDR4 or DDR5, which lets you reuse old memory.

Finally, integrated graphics. If you're not buying a discrete GPU, only the Ryzen 5 8600G games at 1080p on its own. The 7600, 9600X and 9900X have output-only graphics for troubleshooting, while the 9800X3D, 245KF and i5-14400F have none at all and demand a card just to show a picture. The common mistake is buying an F or KF chip and forgetting the GPU line entirely.

Proof C · The write-ups

↑ All doubts

“You’ve read the same three reviews I have.”

The ten write-ups

Ten write-ups, none folded away. We don’t lab-test, so every line below sticks to what can be defended: the published sheet, the owner ratings on the UK listings and our own reviews.

Best Overall Value

1. AMD RYZEN ™ 7 9800X 3D Desktop Processor (8-core/16-thread, 104MB cache, up to 5.2 GHz max boost)

Start with the cache, because that's the whole story here. 104MB of it, most of that a stacked V-Cache layer sitting under the cores, and it's the reason this chip leaves everything else on this page behind in games. Our review lists the 9800X3D as the fastest gaming processor available, with 15 to 25 percent frame rate improvements over non-X3D chips and measurable leads in both average frame rates and 1% lows over every competitor. That last part matters more than headline averages. 1% lows are the stutter you actually feel.

It's an eight-core, 16-thread Zen 5 part on AM5, boosting to 5.2GHz with a 4.7GHz base. The 120W TDP is modest for the performance on offer, and our review notes it performs well above competing chips that draw considerably more power for similar or lesser gaming output. Compared to the Ryzen 7 9700X further down this list, the 9800X3D is the meaningfully faster gaming chip in cache-sensitive titles. That's the trade: the 9700X is cooler and cheaper, the X3D wins the frames.

Two honest limits. There's no integrated graphics, so a discrete GPU is mandatory even to get a picture on screen while troubleshooting. And the eight-core layout caps heavy productivity: our review points out the Ryzen 9 9950X and Core Ultra 9 285K are substantially faster for rendering and compilation. This is a gaming chip that does everything else competently, not a workstation part.

The AM5 platform is the long game. PCIe Gen 5 for GPU and NVMe, DDR5, and AMD's stated socket support through at least 2027. Our review notes owners on an existing AM5 Zen 4 board can drop this straight in with a BIOS update, which validates the earlier platform spend. One physical detail from the listing: no cooler in the box, and our review flags that sustained loads under poor cooling can run it hot. Buy a decent cooler with it, not as an afterthought. On the numbers it earns its place: 4.8 stars from 6,141 Amazon UK ratings, and a 9.2 in our review.

Pros

  • Largest cache on this list at 104MB, the source of its frame-rate lead
  • AM5 socket with stated support through at least 2027 gives a real upgrade path
  • Zen 5 IPC lifts single-thread response in desktop work, not just games
  • 4.8 stars from 6,141 UK ratings

Cons

  • No integrated graphics, so a GPU is required even for basic display output
  • No cooler supplied, and V-Cache makes good cooling non-negotiable
  • Eight cores limit heavy rendering versus 12 and 16-core rivals

Buy on Amazon£374.99Read full review

Best AM5 Starter

2. AMD Ryzen 5 7600 Processor (radeon graphics integrated, 6 cores/12 threads, 65W TDP, AM5 Socket, 38MB cache, up to 5.1 GHz max boost, Wraith Stealth Cooler)

This is an affordable way onto AM5, and the reason is the box contents. Six Zen 4 cores, 65W, a 5.1GHz boost, and a Wraith Stealth cooler included. That last bit saves £30 to £50 you'd otherwise spend on the 9600X or 9700X, both of which arrive bare. For a first-time builder watching every pound, that's the difference between one order and two.

It carries Radeon graphics from the Ryzen 7000 line, so you get display output and a troubleshooting fallback without a discrete card. Not a gaming iGPU, mind. If you want to actually play games without a GPU, the Ryzen 5 8600G lower down is the chip for that. The 7600 assumes you'll pair it with a graphics card and just wants to keep costs down elsewhere.

Against the newer Ryzen 5 9600X, the gap is architecture: the 9600X is Zen 5 with more single-thread grunt and a higher 5.4GHz boost, but it's dearer and coolerless. The 7600 trades a bit of raw speed for the bundled cooler and a lower entry price, which for a budget 1080p build is often the smarter call. Same AM5 socket, same upgrade path through 2027, same DDR5 requirement that adds to the total build cost. Owner sentiment is strong: 4.7 stars from 3,251 UK ratings. It's the pragmatic entry point, not the fastest chip, and it knows it.

Pros

  • Wraith Stealth cooler included, saving £30 to £50 over coolerless rivals
  • 65W TDP keeps heat and running costs low for a 1080p build
  • AM5 socket means a later drop-in upgrade without a new board
  • 4.7 stars from 3,251 UK ratings

Cons

  • DDR5 is mandatory, adding cost versus older DDR4 platforms
  • Radeon iGPU is for output only, not real gaming
  • Zen 4 six-core trails the newer Zen 5 chips in single-thread work

Buy on Amazon£158.59Read full review

Best for Content Creators

3. Intel® Core™ i7-14700K Desktop Processor 20 cores (8 P-cores + 12 E-cores) up to 5.6 GHz

Twenty cores. That's eight performance cores and twelve efficiency cores, 28 threads total, and it's why this Intel chip is the one to look at if you game and also edit or stream on the same box. Our review calls it a solid mid-range choice for gamers who also stream or edit content, with strong multi-threaded throughput and a genuinely useful Quick Sync video encoder. The 5.6GHz P-core boost matches the Ryzen 9 9900X at the top of this list.

The flexibility is real too. The listing states DDR4 and DDR5 support plus PCIe 5.0 and 4.0, so you can reuse older memory or build fresh. That's an option the AM5 chips here don't give you, since they're all DDR5 only. If you're migrating from an older DDR4 system on a budget, that matters.

But the socket is the sting. Our review notes LGA1700 is end-of-life with no CPU upgrade path, so this board takes no faster chip later. Set against the Ryzen 7 9700X, which sits on a socket supported to 2027, you're buying a dead end for more cores now. There's no stock cooler either, and our review points out power efficiency lags behind AMD's Ryzen alternatives and thermal management wants quality cooling. Our review scores it 8 out of 10; owners give it 4.6 stars from 1,362 UK ratings. For a creator who values cores and DDR4 reuse today, it stacks up. For pure gaming or long-term upgrades, look at AMD.

Pros

  • 20 cores and 28 threads, the highest core count on this page for content work
  • Listing states DDR4 or DDR5 support, letting you reuse old memory
  • 5.6GHz boost, level with the 9900X at the top of this list
  • Wide choice of Z790 and 600 Series boards at varied prices

Cons

  • LGA1700 is end-of-life with no future CPU to upgrade to
  • No cooler included and it needs a good one
  • Our review notes it's less power-efficient than Ryzen 7000 rivals

Buy on Amazon£345.97Read full review

Best Budget

4. Intel® Core™ Ultra 5 Desktop Processor 245KF 14 cores (6 P-cores + 8 E-cores) up to 5.2 GHz

Who shouldn't buy this? Anyone chasing all-core productivity, and anyone who wants a chip that outlives the board. Our review is blunt: the 245KF is a narrow fit, best for budget gamers with discrete GPUs who skip heavy workloads. Get that, and it makes sense at the low end of this price range.

It's a 14-core Arrow Lake part, six P-cores and eight E-cores, boosting to 5.2GHz. Our review lists respectable 1080p gaming and improved power efficiency as the wins, with PCIe 5.0 and DDR5 on the Z890 platform. The KF suffix means no integrated graphics, so a GPU is mandatory, and there's no cooler in the box. Our review also flags that dropping Hyper-Threading on the P-cores limits heavily-threaded work, which is where the weak multi-core score comes from.

Against the Ryzen 5 9600X, which our review says runs cooler at 65W, the 245KF's 125W base power runs warmer for broadly similar gaming. The Intel gives you more cores and the newer LGA1851 platform; the AMD gives efficiency and a longer socket life. For a first gaming build on a strict budget with a graphics card already sorted, the 245KF earns its badge. Owners rate it 4.4 stars from 147 UK ratings, and our review gives it 8 out of 10.

Pros

  • 14 cores and PCIe 5.0 at the bottom of this price range
  • Unlocked multiplier for overclocking on Z890 boards
  • LGA1851 is a newer socket than the 14th Gen Intel chips here

Cons

  • No integrated graphics, so a discrete GPU is required
  • No cooler supplied, adding to build cost
  • Our review notes 125W base power runs warmer than the 65W 9600X
  • No Hyper-Threading on P-cores caps heavily-threaded performance

Buy on Amazon£139.99Read full review

Best Efficient Eight-Core

5. AMD Ryzen 7 9700X Processor (8 Cores/16 Threads) 65W DTP, AM5 socket, 40MB Cache, Up to 5.5 GHz max boost frequency, no cooler

65W for eight Zen 5 cores boosting to 5.5GHz. That number is the pitch. Our review calls the 9700X the mid-range gaming processor that genuinely deserves its positioning, with real IPC gains over Zen 4 and cool, quiet running that keeps electricity costs down. If you want strong gaming without the heat and noise of the Intel K chips, this is it.

The homogeneous eight-core layout, with no efficiency cores, helps game scheduling and 1% low frame times, per our review. It's the same core count as the 9800X3D at the top of this list, but without the stacked V-Cache, so our review is clear that the 9800X3D is meaningfully faster in cache-sensitive titles. The 9700X is the pick if gaming isn't your sole priority and you'd rather bank the saving and the lower power draw.

No cooler in the box, which first-time builders sometimes miss, though our review notes AM4 coolers fit via the existing bracket, so upgraders may not need to buy one. DDR5 only, PCIe 5.0 for GPU and primary NVMe, and the AM5 socket's long life. Eight cores may feel tight in four to six years for heavy threaded pro work, per our review. Owners give it 4.8 stars from 2,666 UK ratings, and our review scores it 9 out of 10.

Pros

  • 65W TDP for eight cores means cool, quiet, cheap-to-run operation
  • AM4 coolers fit via bracket, saving upgraders a purchase
  • Homogeneous eight-core design aids consistent 1% lows
  • 4.8 stars from 2,666 UK ratings

Cons

  • No cooler in the box, an unexpected cost for new builders
  • DDR5 only, so AM4 upgraders must buy new RAM
  • The 9800X3D is clearly faster in cache-heavy games

Buy on Amazon£269.99Read full review

Best for Multitasking

6. AMD Ryzen 9 9900X Processor (radeon graphics integrated, 12 Cores/24 Threads, 120W DTP, AM5 Socket, 76MB Cache, Up to 5.6 GHz max boost frequency, No Cooler)

Twelve cores and 24 threads is the reason to pick this over the eight-core 9700X above. Our review calls the 9900X excellent for anyone who needs fast gaming and serious productivity in one package, with the Zen 5 IPC gains and a 5.6GHz boost carrying the speed. If you render, compile or stream while gaming, those four extra cores over the 9700X do real work.

It's 120W, which our review notes is significantly more efficient than the 7900X it replaces, so you get the extra cores without a huge power penalty. Integrated Radeon graphics handle setup and act as a fallback display, though it's not for gaming. The AM5 socket brings the same 2027-plus upgrade path as the rest of the AMD chips here.

The catch is aimed at pure gamers: our review says they can get similar gaming performance cheaper from the Ryzen 7 9700X, so the 9900X only makes sense if you'll use the productivity cores. No cooler included, and our review stresses you genuinely need a decent one at 120W. AM5 entry cost sits higher than older sockets. Owners rate it 4.8 stars from 1,697 UK ratings; our review gives 8.5 out of 10.

Pros

  • 12 cores and 24 threads for simultaneous gaming and productivity
  • 120W is more efficient than the previous-gen 12-core it replaces
  • Integrated Radeon graphics for setup and fallback output
  • 4.8 stars from 1,697 UK ratings

Cons

  • No cooler included and 120W demands a good one
  • Pure gamers get similar frames cheaper from the 9700X
  • AM5 entry cost is higher than older sockets

Buy on Amazon£329.99Read full review

Best AM4 Upgrade

7. AMD Ryzen 5 5600X Processor (6 Cores/12Threads, 65W TDP, AM4 Socket, 35MB Cache, up to 4.6 GHz Max Boost, Wraith Stealth Cooler)

Nearly 30,000 people can't all be wrong. This AM4 six-core has 4.8 stars from 29,715 UK ratings, and our review still calls it a brilliant gaming CPU, rivalling far dearer chips when paired with a mid-range graphics card. It's Zen 3, 65W, with a Wraith Stealth cooler in the box.

The pitch is upgrades. If you're on an older AM4 board with a Ryzen 2000 or 3000 chip, this drops in without a new motherboard, no DDR5, no platform reshuffle. That's a cheaper leap than any AM5 chip here, all of which force new RAM and a new board. Our review notes the 32MB L3 cache helps gaming latency, and the bundled cooler means no extra purchase to get running.

The honest limits: AM4 is a finished platform, so this is the end of that upgrade road, and our review says six cores can feel tight under heavy sustained multi-threaded work like video rendering. There's no integrated graphics, so a GPU is required. Against the newer Ryzen 5 8600G on AM5, the 5600X is the better pure upgrade for existing AM4 owners; the 8600G is the better fresh build. Our review scores it 9 out of 10.

Pros

  • 4.8 stars from 29,715 UK ratings
  • Drops into existing AM4 boards with no new RAM or board
  • Wraith Stealth cooler included in the box
  • 32MB L3 cache benefits gaming latency

Cons

  • AM4 is finished, so this is the last upgrade for that board
  • No integrated graphics, GPU required for any display
  • Six cores strain under heavy sustained rendering

Buy on Amazon£147.98Read full review

Best for Beginners

8. AMD Ryzen 5 8600G processor (integrated Radeon Graphics,Ryzen AI, 6 cores/12 threads, 65W TDP, AM5 Socket, Cache 22MB, up to 5,0Ghz max booth, with wraith stealth cooler)

This is the one chip here you can build a whole gaming PC around with no graphics card. The Radeon 760M iGPU is genuinely capable for 1080p gaming, per our review, which is a different league from the display-only graphics on the 7600 or 5600X. Six Zen 4 cores, 65W, a Wraith Stealth cooler included, and the AM5 socket for a later upgrade. Our review does note the iGPU drops off without fast dual-channel DDR5, so pair it with quick memory. Owners rate it 4.7 stars from 1,266 UK ratings.

Pros

  • Radeon 760M iGPU handles real 1080p gaming with no GPU
  • Wraith Stealth cooler included
  • AM5 socket for a future CPU or add-in GPU upgrade

Cons

  • iGPU performance needs fast dual-channel DDR5 to hold up
  • Six cores trail Intel's 10-core i5-14400F in threaded work

Buy on Amazon£159.00Read full review

Best for Compact Builds

9. Intel® Core™ i5-14400F Desktop Processor 10 cores (6 P-cores + 4 E-cores) up to 4.7 GHz

Ten cores, 65W, and a Laminar RM1 cooler in the box. Our review says it handles 1080p and 1440p gaming without bottlenecks and suits small form factor and ITX builds thanks to those manageable thermals. The listing states DDR4 or DDR5 support, so you can reuse old memory to keep a compact build cheap. There's no iGPU on the F chip, so a GPU is required, and the multiplier is locked, so 4.7GHz is the ceiling. Against the six-core 8600G above, the 14400F wins on core count for threaded work but loses the integrated graphics. Owners give it 4.7 stars from 581 UK ratings.

Pros

  • 10 cores at 65W suit compact and ITX builds
  • Laminar RM1 cooler included in the box
  • Listing states DDR4 or DDR5 for memory reuse

Cons

  • No integrated graphics, GPU required at all times
  • Locked multiplier caps it at 4.7GHz
  • LGA1700 is end-of-life with no in-socket upgrade

Buy on Amazon£148.97Read full review

Best Value Gaming

10. AMD Ryzen 5 9600X Processor (radeon graphics included, 6 Cores/12 Threads, 65W TDP, Socket AM5, Cache 38MB, up to 5.4 GHz max boost Frequency, no cooler)

The newest six-core here, and our review calls it a solid Zen 5 gaming and productivity chip with strong single-thread performance and excellent 65W efficiency, boosting to 5.4GHz. It justifies a fresh AM5 build with an upgrade path through 2027. No cooler is included, unlike the 7600 it sits near in price, and it's DDR5 only. Six cores limit heavy multi-thread work like 4K video, and the RDNA 2 graphics are output-only, not for gaming. Owners rate it 4.8 stars from 4,020 UK ratings, and our review scores 9 out of 10.

Pros

  • Zen 5 single-thread performance keeps frame times low
  • 65W runs cool and quiet under sustained gaming
  • AM4 coolers fit, saving upgraders a purchase
  • 4.8 stars from 4,020 UK ratings

Cons

  • No cooler in the box, unlike the nearby 7600
  • DDR5 only, no DDR4 support
  • Six cores limit 4K video and 3D rendering

Buy on Amazon£160.97Read full review

Proof D · Method & disclosure

↑ All doubts

“You’re paid to say this.”

Method & disclosure

This page carries affiliate links; they never set the order. We don’t lab-test: rankings come from published specifications, the owner ratings on the UK listings and our own reviews.

How We Compared These

We ranked these 10 processors on published manufacturer specifications, verified Amazon UK owner star ratings and rating counts, and our own research-led reviews. Core counts, cache, TDP, socket and memory support come from the spec sheets and listings; where a listing and the spec record disagreed, we went with the spec. We assessed value by budget bracket rather than a fixed price, since prices shift daily and the live shortcode on this page shows the current figure. No chip here was bench-tested by us; the performance points are drawn from our reviews and owner rating data.

Motives inspected? Settled.Next · Proof EThe verdict ↓

Proof E · The verdict

↑ All doubts

“Every guide crowns something.”

The verdict, cross-examined

A crown that can’t be argued with isn’t proof of quality; it’s proof nobody checked. So rather than restate the winner’s virtues, we defend the crown against the strongest cases to take it.

AMD Ryzen ™ 7 9800X 3D Desktop Processor

Cross-examination · Three challengers, taken seriously

The £216 argumentAMD Ryzen 5 7600 Processor

At £158.59 today against the winner’s £374.99, its strongest case is the £216 it hands back. Owners rate it 4.7 from 3,277 ratings. Our review scores it 8.5 against the winner’s 9.2. If the cheaper pick covers the job you actually do, take the saving with a clear conscience. The crown stays where it is because rank follows fit for the job in the title, not the receipt, and its full argument is in the write-up above.

The £29 argumentIntel® Core™ i7-14700K Desktop Processor 20 cores

At £345.97 today against the winner’s £374.99, its strongest case is the £29 it hands back. Owners rate it 4.6 from 1,373 ratings. Our review scores it 8.0 against the winner’s 9.2. If the cheaper pick covers the job you actually do, take the saving with a clear conscience. The crown stays where it is because rank follows fit for the job in the title, not the receipt, and its full argument is in the write-up above.

The £235 argumentIntel® Core™ Ultra 5 Desktop Processor 245KF 14 cores

At £139.99 today against the winner’s £374.99, its strongest case is the £235 it hands back. Owners rate it 4.4 from 150 ratings. Our review scores it 8.0 against the winner’s 9.2. If the cheaper pick covers the job you actually do, take the saving with a clear conscience. The crown stays where it is because rank follows fit for the job in the title, not the receipt, and its full argument is in the write-up above.

The original verdict, preserved in full

Final Verdict: Best CPUs Under £400

If gaming is the priority and the budget stretches, the AMD Ryzen 7 9800X3D is the clear winner: nothing on this list matches its frame rates, and the AM5 socket means it won't be a dead end. At the other end, the Intel Core Ultra 5 245KF is the budget pick for a first gaming build with a GPU already sorted, though its warmer power draw and weaker multi-core work narrow the case. For most people building fresh, the Ryzen 5 9600X or the eight-core 9700X hit the value sweet spot, while AM4 upgraders should grab the 5600X and its bundled cooler. Match the chip to your socket and your GPU plans first, and the right pick falls out of that.

We read everything, we hide nothing, and we sign what we publish. Corrections are welcome and printed when we’re wrong.

The Vivid Repairs desk

Vivid Repairs · 7 October 2026

End of the full guide · Back to the doubt index ↑ · The FAQ is next ↓

§ Questions

Questions people actually ask

Frequently Asked Questions

For some builds, yes. The Intel Core i7-14700K on this page has 20 cores, the most here, which suits rendering and streaming alongside games, and the Core Ultra 5 245KF is a sensible budget gaming chip if you already own a graphics card. For pure gaming, AMD leads: the Ryzen 7 9800X3D is faster in games than anything Intel sells under £400. If you buy a 14th Gen Intel chip, update the motherboard BIOS first: Intel’s 0x12B microcode addresses the voltage instability that affected 13th and 14th Gen processors.

The AMD Ryzen 7 9800X3D. Its 104MB of cache, most of it stacked V-Cache, gives it higher frame rates and steadier 1% lows than any other chip on this page. On a tighter budget, the Ryzen 5 7600 and Ryzen 5 9600X are strong 1080p gaming chips on the same AM5 platform, and the Intel Core Ultra 5 245KF is a capable budget option if you already own a graphics card.

AM5 for a new build. The Ryzen 5 7600, 9600X, 8600G, Ryzen 7 9700X, 9800X3D and Ryzen 9 9900X all use AM5, which AMD supports through at least 2027, so a board bought now can take a faster chip later. AM4 only makes sense if you already own an AM4 board: the Ryzen 5 5600X drops straight in with your existing DDR4 memory, but it is the end of that upgrade road.

Aim for more cores. The Intel Core i7-14700K (20 cores, 28 threads) and the AMD Ryzen 9 9900X (12 cores, 24 threads) are the two strongest here for rendering, compiling and streaming. The Ryzen 9 9900X sits on AM5 with an upgrade path; the i7-14700K offers more cores and DDR4 memory reuse but sits on a socket with no further upgrades.

Some do. The Ryzen 5 7600, Ryzen 5 5600X, Ryzen 5 8600G and Intel i5-14400F all ship with a stock cooler in the box. The X3D, 9700X, 9900X, 9600X and both Intel K/KF chips here do not, so budget for an aftermarket cooler on those.

§ Sign-off

That’s the field: ten cpus under £400, ranked for the job in the title and nothing else. We read the published specifications, the owner ratings and our own reviews; we haven’t handled these products, and no maker moves the order. Figures checked against the live Amazon UK listings, page updated 7 October 2026.

The Vivid Repairs desk