Buying Guide
The Best CPUs for Machine Learning
Five processors compared, from the Ryzen 9 9900X to the Ryzen 9 7950X3D, with the trade-offs of each named.
By Alex Morgan, PC Hardware Editor
12 min read5 products evaluated
For machine learning the GPU does the training, but the CPU feeds data, runs preprocessing and handles smaller models. Every pick has 12 or more cores on a current AM5 or LGA1851 platform, ordered by thread count.
Our comparison rests on published figures for L3 cache, max boost and cores / threads; where a maker leaves out L3 cache, we say so, and no figure here comes from our own testing.
Quick Picks
Which of the 5 picks to look at first. Tap a name for the full analysis.
Also Consider
AMD Ryzen 9 7950X16MB of L2 plus 64MB of L3 cache.
Best for: Buyers who want 16MB of L2 plus 64MB of L3 cache.
Check price for AMD Ryzen 9 7950X on Amazon (opens in a new tab)
Strong Alternative
AMD Ryzen 9 9950XAMD's recommendation of a liquid cooler.
Best for: Buyers who want AMD's recommendation of a liquid cooler.
Check price for AMD Ryzen 9 9950X on Amazon (opens in a new tab)
Premium Pick
AMD Ryzen 9 7950X3D3D V-Cache aimed at gaming and creator work at the highest price in the group.
Best for: Buyers for whom price is not the deciding factor, since the Ryzen 9 9900X costs less.
Check price for AMD Ryzen 9 7950X3D on Amazon (opens in a new tab)Lowest Price Here
AMD Ryzen 9 9900XUndercutting the Ryzen 9 7900 on price when we checked.
Best for: Keeping the cost under $500.
Check price for AMD Ryzen 9 9900X on Amazon (opens in a new tab)
Lowest Rated Power
AMD Ryzen 9 7900The lowest rated power here (65W).
Best for: Buyers who put rated power first.
Check price for AMD Ryzen 9 7900 on Amazon (opens in a new tab)
| Pick | Why it stands out | Best for | Check price |
|---|---|---|---|
| 16MB of L2 plus 64MB of L3 cache. | Buyers who want 16MB of L2 plus 64MB of L3 cache. | Check price for AMD Ryzen 9 7950X on Amazon (opens in a new tab) |
| AMD's recommendation of a liquid cooler. | Buyers who want AMD's recommendation of a liquid cooler. | Check price for AMD Ryzen 9 9950X on Amazon (opens in a new tab) |
| 3D V-Cache aimed at gaming and creator work at the highest price in the group. | Buyers for whom price is not the deciding factor, since the Ryzen 9 9900X costs less. | Check price for AMD Ryzen 9 7950X3D on Amazon (opens in a new tab) |
| Undercutting the Ryzen 9 7900 on price when we checked. | Keeping the cost under $500. | Check price for AMD Ryzen 9 9900X on Amazon (opens in a new tab) |
| The lowest rated power here (65W). | Buyers who put rated power first. | Check price for AMD Ryzen 9 7900 on Amazon (opens in a new tab) |
Our Picks
Also Consider1 of 5
AMD Ryzen 9 7950X
What the Ryzen 9 7950X brings to the table is 16MB of L2 plus 64MB of L3 cache, plus a 5nm process with Radeon Graphics built in.
Best for
- Buyers who want 16MB of L2 plus 64MB of L3 cache.
Skip if
- The maker gives no boost clock, so skip it if that figure decides your choice.
Why we like it
It also offers a 64MB L3 cache and offers a 16 cores core count. It matches the Ryzen 9 9950X and the Ryzen 9 7950X3D on core count (16 cores). It needs an AM5 board (A620, B650, B850, X670 or X870 series) and DDR5 memory; check the board's CPU support list for the minimum BIOS version.
You also get this: integrated graphics for display output without a graphics card. Its price falls between the Ryzen 9 7900 and the Ryzen 9 9950X, based on our last check. Buyers who need a confirmed boost clock should compare it with the Ryzen 9 9950X, which offers 5.7GHz.
Key specs
- L3 cache
- 64MB
- Cores / threads
- 16 cores
- Threads
- 32
- Socket
- AM5
- Integrated graphics
- Yes
Pros
- 64MB of L3 cache
- 16 cores for encoding and background work
- Integrated graphics for display output without a graphics card
- 16MB of L2 plus 64MB of L3 cache
Cons
- No published boost clock
- No published rated power
- Costs more than the Ryzen 9 9900X at the time of writing
Strong Alternative2 of 5
AMD Ryzen 9 9950X
The Ryzen 9 9950X gives 16 cores and 32 threads without the X3D premium.
Best for
- Buyers who want AMD's recommendation of a liquid cooler.
Skip if
- Skip it if this is a deal-breaker for you: 170W rating calls for a large air cooler or a 280mm-plus AIO.
Why we like it
It is the better buy when CPU encoding and editing matter more than the last few frames per second. It matches the Ryzen 9 7950X3D on boost clock (5.7GHz). On core count it ties with the Ryzen 9 7950X and the Ryzen 9 7950X3D at 16 cores.
On rated power it trails the group at 170W, while the Ryzen 9 7900 offers 65W. It also comes with AMD's recommendation of a liquid cooler. It needs an AM5 board (A620, B650, B850, X670 or X870 series) and DDR5 memory; a 600-series board may need a BIOS update first, so check the maker's CPU support list for the minimum version.
Budget for a dual-tower air cooler or a 240mm-plus AIO, since none is included. When we checked, only the Ryzen 9 7950X and cheaper picks cost less, and the Ryzen 9 7950X3D cost more.
Key specs
- L3 cache
- 64MB
- Max boost
- 5.7GHz
- Cores / threads
- 16 cores
- Rated power
- 170W
- Threads
- 32
- Socket
- AM5
- Memory
- DDR5
- Cooler in box
- No
- Integrated graphics
- Yes
Pros
- 64MB of L3 cache
- 5.7GHz maximum boost
- 16 cores for encoding and background work
- Integrated graphics for display output without a graphics card
Cons
- 170W rating calls for a large air cooler or a 280mm-plus AIO
- No cooler in the box
- Rated power trails the Ryzen 9 7900 (65W)
The catch
Rated power is its weakest area, and the Ryzen 9 7900 covers it better at 65W.
Premium Pick3 of 5
AMD Ryzen 9 7950X3D
What the Ryzen 9 7950X3D brings to the table is 3D V-Cache aimed at gaming and creator work, plus a liquid cooler recommended by AMD.
Best for
- Buyers for whom price is not the deciding factor, since the Ryzen 9 9900X costs less.
Skip if
- Pass on it if no cooler in the box rules it out for your setup.
Why we like it
It also offers a 5.7GHz boost clock and offers a 16 cores core count. It matches the Ryzen 9 9950X on boost clock (5.7GHz). On core count it ties with the Ryzen 9 7950X and the Ryzen 9 9950X at 16 cores.
It needs an AM5 board (A620, B650, B850, X670 or X870 series) and DDR5 memory; check the board's CPU support list for the minimum BIOS version. No cooler is included; a single-tower air cooler is enough at its rating. At our last price check it topped the group, with the Ryzen 9 9950X the nearest cheaper option. If you want a confirmed L3 cache, look to the Ryzen 9 7950X instead: it offers 64MB, while this one gives no figure.
Key specs
- Max boost
- 5.7GHz
- Cores / threads
- 16 cores
- Threads
- 32
- Socket
- AM5
- Memory
- DDR5
- Cooler in box
- No
Pros
- 5.7GHz maximum boost
- 16 cores for encoding and background work
- 3D V-Cache aimed at gaming and creator work
- Liquid cooler recommended by AMD
Cons
- No cooler in the box
- No published L3 cache
- No published rated power
Lowest Price Here4 of 5
AMD Ryzen 9 9900X
The Ryzen 9 9900X steps down to 12 cores on Zen 5.
Best for
- Keeping the cost under $500.
Skip if
- Skip it if this is a deal-breaker for you: no cooler in the box.
Why we like it
It leaves plenty of threads for an encoder alongside a game, with a lower power rating than the 16-core chips. Its 5.6GHz boost clock ranks third of 4 here, behind the Ryzen 9 9950X (5.7GHz) and ahead of the Ryzen 9 7900 (5.4GHz). On core count it ties with the Ryzen 9 7900 at 12 cores.
On rated power it sits mid-pack at 120W: the Ryzen 9 7900 offers 65W, and the Ryzen 9 9950X comes in at 170W. It needs an AM5 board (A620, B650, B850, X670 or X870 series) and DDR5 memory; a 600-series board may need a BIOS update first, so check the maker's CPU support list for the minimum version. Budget for a dual-tower air cooler or a 240mm-plus AIO, since none is included. It cost the least of the 5 picks at the time of writing, with the Ryzen 9 7900 the next step up.
Key specs
- L3 cache
- 64MB
- Max boost
- 5.6GHz
- Cores / threads
- 12 cores
- Rated power
- 120W
- Threads
- 24
- Socket
- AM5
- Memory
- DDR5
- Cooler in box
- No
- Integrated graphics
- Yes
Pros
- 64MB of L3 cache
- 5.6GHz maximum boost
- 12 cores for encoding and background work
- Integrated graphics for display output without a graphics card
Cons
- No cooler in the box
The catch
What it gives up: no cooler in box, unlike the Ryzen 9 7900; by contrast, the Ryzen 9 7900 has it.
Lowest Rated Power5 of 5
AMD Ryzen 9 7900
The Ryzen 9 7900 is the 65W twelve-core AM5 chip with a Wraith Prism cooler included.
Best for
- Buyers who put rated power first.
Skip if
- Skip it if boost clock matters most to you; the Ryzen 9 9950X offers 5.7GHz.
Why we like it
It trades a little boost clock for lower heat. Its 5.4GHz boost clock is the lowest in this group; the Ryzen 9 9950X leads at 5.7GHz. On core count it ties with the Ryzen 9 9900X at 12 cores.
Nothing else here matches its 65W rated power; the Ryzen 9 9900X comes closest at 120W. It also offers 12 cores at a 65W rating. It needs an AM5 board (A620, B650, B850, X670 or X870 series) and DDR5 memory; check the board's CPU support list for the minimum BIOS version.
When we checked, only the Ryzen 9 9900X cost less, and the Ryzen 9 7950X cost more. L3 cache is its weakest area, and the Ryzen 9 7950X covers it better at 64MB.
Key specs
- L3 cache
- 64MB
- Max boost
- 5.4GHz
- Cores / threads
- 12 cores
- Rated power
- 65W
- Threads
- 24
- Socket
- AM5
- Memory
- DDR5
- Cooler in box
- Yes
- Integrated graphics
- Yes
Pros
- 64MB of L3 cache
- 12 cores for encoding and background work
- 65W rating suits a modest air cooler
- Wraith Stealth cooler in the box
Cons
- Boost clock trails the Ryzen 9 9950X (5.7GHz)
- Core count trails the Ryzen 9 7950X (16 cores)
- Costs more than the Ryzen 9 9900X at the time of writing
How We Chose
Alex Morgan compared the manufacturer specifications, connectivity, warranty terms and compatibility of every pick. Figures come from the makers unless a third-party source is named; we did not test these products ourselves.
- The figures behind the order
- We set side by side five processors on L3 cache, boost clock, core count and rated power from manufacturer specifications. We did not test them in-house, and L3 cache and boost clock are missing for at least one pick.
- The shared baseline
- All 5, from the Ryzen 9 7950X to the Ryzen 9 7900, state core count, threads and socket and share AM5 socket.
- Where the specs have gaps
- The Ryzen 9 7950X3D gives no L3 cache; the Ryzen 9 7950X gives no boost clock.
- Price range
- At our last check the picks ran from the Ryzen 9 9900X ($250 to $500) to the Ryzen 9 7950X3D ($500 to $1000).
What to Look for in a CPUs for Machine Learning
Key buying criteria so you get the right fit the first time.
Core count across these picks
The Ryzen 9 7950X tops core count at 16 cores and the Ryzen 9 7900 sits lowest at 12 cores; 3 picks share the top figure. If core count is your first filter, the Ryzen 9 7950X sets the ceiling at 16 cores.
Boost clock
Across these 4 picks boost clock spans 5.4GHz (the Ryzen 9 7900) to 5.7GHz (the Ryzen 9 9950X). Start with the Ryzen 9 9950X if boost clock decides it. The Ryzen 9 7950X gives no boost clock figure, so 4 of 5 picks are compared here.
A desktop CPU seated in its motherboard socket with the retention frame open How much rated power you need
Across these 3 picks rated power spans 170W (the Ryzen 9 9950X) to 65W (the Ryzen 9 7900). For less, the Ryzen 9 9900X is the runner-up at 120W. The Ryzen 9 7950X and the Ryzen 9 7950X3D give no rated power figure, so 3 of 5 picks are compared here.
Features beyond the spec table
The Ryzen 9 7950X3D: a liquid cooler recommended by AMD. The Ryzen 9 9900X: the Zen 5 architecture. The Ryzen 9 7900: 12 cores at a 65W rating.
Where your budget lands
$250 to $500 buys the Ryzen 9 9900X and the Ryzen 9 7900; $500 to $1000 buys the Ryzen 9 7950X, the Ryzen 9 9950X and the Ryzen 9 7950X3D at our last check.
How to Choose a CPUs for Machine Learning
By priority
| Priority | Consider | Why |
|---|---|---|
| Buyers who want 16MB of L2 plus 64MB of L3 cache | Ryzen 9 7950X | 16MB of L2 plus 64MB of L3 cache |
| Buyers who want AMD's recommendation of a liquid cooler | Ryzen 9 9950X | AMD's recommendation of a liquid cooler |
| Buyers for whom price is not the deciding factor, since the Ryzen 9 9900X costs less | Ryzen 9 7950X3D | 3D V-Cache aimed at gaming and creator work at the highest price in the group |
| Keeping the cost under $500 | Ryzen 9 9900X | Undercutting the Ryzen 9 7900 on price when we checked |
| Buyers who put rated power first | Ryzen 9 7900 | The lowest rated power here (65W) |
Scroll sideways to see every column.
Key specs side by side
The Ryzen 9 7950X leads on core count at 16 cores, ahead of the Ryzen 9 9950X at 16 cores. "Not listed" marks L3 cache where the Ryzen 9 7950X3D leaves the figure out.
| Processor | L3 cache | Max boost | Cores / threads | Rated power |
|---|---|---|---|---|
| Ryzen 9 7950X | 64MB | Not listed | 16 cores | Not listed |
| Ryzen 9 9950X | 64MB | 5.7GHz | 16 cores | 170W |
| Ryzen 9 7950X3D | Not listed | 5.7GHz | 16 cores | Not listed |
| Ryzen 9 9900X | 64MB | 5.6GHz | 12 cores | 120W |
| Ryzen 9 7900 | 64MB | 5.4GHz | 12 cores | 65W |
Scroll sideways to see every column.
By price at the time of writing
At our last check the cheapest pick, the Ryzen 9 9900X, sat in the $250 to $500 tier, 2 tiers in all up to the Ryzen 9 7950X3D at $500 to $1000; Amazon prices move, so recheck before buying.
| Price tier | Processors |
|---|---|
| About $250 to $500 | Ryzen 9 9900X, Ryzen 9 7900 |
| About $500 to $1000 | Ryzen 9 7950X, Ryzen 9 9950X, Ryzen 9 7950X3D |
Frequently Asked Questions
Is the Ryzen 9 7900 ahead of the Ryzen 9 9900X on rated power?
The Ryzen 9 7900 is lowest on rated power at 65W; the Ryzen 9 9900X follows at 120W, 46% apart. The Ryzen 9 9950X closes the ranking at 170W. No rated power figure is published for the Ryzen 9 7950X and the Ryzen 9 7950X3D, which leaves 3 of 5 picks ranked here.
Is the Ryzen 9 7950X3D worth paying more than the Ryzen 9 9900X?
What it brings is core count (16 cores against 12 cores) and boost clock (5.7GHz against 5.6GHz). The Ryzen 9 9900X sat in the $250 to $500 tier and the Ryzen 9 7950X3D in the $500 to $1000 tier when we checked, with 3 other picks between them; pay the difference only if core count and boost clock decide your purchase.
What makes the Ryzen 9 7900 the Lowest Rated Power?
The label rests on the lowest rated power here (65W). The Ryzen 9 9900X is next on rated power at 120W, so this pick's 65W is 46% further out. It gives up boost clock (5.4GHz against 5.6GHz) to the Ryzen 9 9900X, the cheapest pick. It is aimed at anyone who puts rated power first.
Which of these processors have cooler in box?
The Ryzen 9 7900 has it; the Ryzen 9 9950X, the Ryzen 9 7950X3D and the Ryzen 9 9900X do not. The maker of the Ryzen 9 7950X doesn't state cooler in box, so 4 of 5 picks are covered here.
Beyond the specs, what sets the Ryzen 9 7950X and the Ryzen 9 9950X apart?
The Ryzen 9 7950X: 16MB of L2 plus 64MB of L3 cache. The Ryzen 9 9950X: AMD's recommendation of a liquid cooler. The Ryzen 9 7950X3D: 3D V-Cache aimed at gaming and creator work.
Bottom Line
Our first pick is the Ryzen 9 7950X, chosen for 16MB of L2 plus 64MB of L3 cache. Look at the Ryzen 9 9950X for AMD's recommendation of a liquid cooler, the Ryzen 9 7950X3D for 3D V-Cache aimed at gaming and creator work at the highest price in the group and the Ryzen 9 9900X for undercutting the Ryzen 9 7900 on price when we checked if those matter more to you.
Spend on the GPU's VRAM first; a faster CPU won't rescue a model that doesn't fit.
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About the author
PC Hardware Editor
Alex covers PC hardware, monitors, components, upgrades and peripherals for The PC Journal, with a focus on helping readers understand specifications, compatibility and meaningful product trade-offs.
Covers: Monitors, Graphics cards, Processors, PC components, Peripherals, Upgrades and compatibility
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