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Intel 9th Gen Intel Core i9-9900X vs Intel 9th Gen Intel Core i9-9940X: Comparison
9th Gen Intel Core i9-9900X vs 9th Gen Intel Core i9-9940X: the l2 cache difference
Start with l2 cache, because it is the widest measured gap between them: 9th Gen Intel Core i9-9900X 10 MB against 9th Gen Intel Core i9-9940X 14 MB, 29% in favour of 9th Gen Intel Core i9-9940X. They differ on core count too, 10 cores on the 9th Gen Intel Core i9-9900X versus 14 cores on the 9th Gen Intel Core i9-9940X. Thread count is not the same on both, 20 threads on the 9th Gen Intel Core i9-9900X versus 28 threads on the 9th Gen Intel Core i9-9940X. There is a split on base clock as well, 3.5 GHz on the 9th Gen Intel Core i9-9900X versus 3.3 GHz on the 9th Gen Intel Core i9-9940X.
Which should you buy, 9th Gen Intel Core i9-9900X or 9th Gen Intel Core i9-9940X?
Take the 9th Gen Intel Core i9-9900X for prosumer content creators wanting HEDT platform memory bandwidth and PCIe lanes at a more accessible entry tier. It is the wrong buy for buyers needing the highest core counts, the i9-9920X, 9940X, and higher-tier X-series chips offer more cores on the same platform. Take the 9th Gen Intel Core i9-9940X for prosumer workstation workloads wanting a mid-tier core count balance within Intel's 9th Gen X-series HEDT stack. It is not the one for buyers with more modest core-count needs, the 9900X or 9920X offer HEDT platform features at a lower price.
What 9th Gen Intel Core i9-9900X and 9th Gen Intel Core i9-9940X have in common
Everything else lines up. Boost clock, tdp, l3 cache, memory channels and pcie lanes read the same on both, so those are not worth weighing. They match on 17 further specifications as well.
Frequently asked questions
Is the CPU Socket the same on the 9th Gen Intel Core i9-9900X and 9th Gen Intel Core i9-9940X?
It is. Both are listed at FCLGA2066, so it is not a reason to pick one over the other.
Specs and benchmarks
Brand
- Intel 9th Gen Intel Core i9-9900X
- Intel
- Intel 9th Gen Intel Core i9-9940X
- Intel
Model Number
- Intel 9th Gen Intel Core i9-9900X
- 9900X
- Intel 9th Gen Intel Core i9-9940X
- 9940X
CPU Socket
- Intel 9th Gen Intel Core i9-9900X
- FCLGA2066
- Intel 9th Gen Intel Core i9-9940X
- FCLGA2066
Product Family
- Intel 9th Gen Intel Core i9-9900X
- Skylake-X, 9th Gen Intel Core
- Intel 9th Gen Intel Core i9-9940X
- Skylake-X, 9th Gen Intel Core
Release Year
- Intel 9th Gen Intel Core i9-9900X
- 2018
- Intel 9th Gen Intel Core i9-9940X
- 2018
Segment
- Intel 9th Gen Intel Core i9-9900X
- HEDT
- Intel 9th Gen Intel Core i9-9940X
- HEDT
Core Count
- Intel 9th Gen Intel Core i9-9900X
- 10 cores
- Intel 9th Gen Intel Core i9-9940X
- 14 cores
Thread Count
- Intel 9th Gen Intel Core i9-9900X
- 20 threads
- Intel 9th Gen Intel Core i9-9940X
- 28 threads
SMT Support
- Intel 9th Gen Intel Core i9-9900X
- Yes
- Intel 9th Gen Intel Core i9-9940X
- Yes
Base Clock
- Intel 9th Gen Intel Core i9-9900X
- 3.5 GHz
- Intel 9th Gen Intel Core i9-9940X
- 3.3 GHz
Boost Clock
- Intel 9th Gen Intel Core i9-9900X
- 4.4 GHz
- Intel 9th Gen Intel Core i9-9940X
- 4.4 GHz
L2 Cache
- Intel 9th Gen Intel Core i9-9900X
- 10 MB-29%
- Intel 9th Gen Intel Core i9-9940X
- 14 MBBest
L3 Cache
- Intel 9th Gen Intel Core i9-9900X
- 19.25 MB
- Intel 9th Gen Intel Core i9-9940X
- 19.25 MB
3D V-Cache
- Intel 9th Gen Intel Core i9-9900X
- No
- Intel 9th Gen Intel Core i9-9940X
- No
Socket
- Intel 9th Gen Intel Core i9-9900X
- FCLGA2066
- Intel 9th Gen Intel Core i9-9940X
- FCLGA2066
Multi-Socket Support
- Intel 9th Gen Intel Core i9-9900X
- Single Socket Only
- Intel 9th Gen Intel Core i9-9940X
- Single Socket Only
Memory Channels
- Intel 9th Gen Intel Core i9-9900X
- 4 channels
- Intel 9th Gen Intel Core i9-9940X
- 4 channels
Max Memory Speed
- Intel 9th Gen Intel Core i9-9900X
- 2666 MT/s
- Intel 9th Gen Intel Core i9-9940X
- 2666 MT/s
Max Memory Capacity
- Intel 9th Gen Intel Core i9-9900X
- 0.125 TB
- Intel 9th Gen Intel Core i9-9940X
- 0.125 TB
ECC Support
- Intel 9th Gen Intel Core i9-9900X
- No
- Intel 9th Gen Intel Core i9-9940X
- No
PCIe Lanes
- Intel 9th Gen Intel Core i9-9900X
- 44 lanes
- Intel 9th Gen Intel Core i9-9940X
- 44 lanes
PCIe Generation
- Intel 9th Gen Intel Core i9-9900X
- PCIe 3.0
- Intel 9th Gen Intel Core i9-9940X
- PCIe 3.0
CXL Support
- Intel 9th Gen Intel Core i9-9900X
- None
- Intel 9th Gen Intel Core i9-9940X
- None
TDP
- Intel 9th Gen Intel Core i9-9900X
- 165 W
- Intel 9th Gen Intel Core i9-9940X
- 165 W
Integrated Graphics
- Intel 9th Gen Intel Core i9-9900X
- No
- Intel 9th Gen Intel Core i9-9940X
- No
AVX-512 Support
- Intel 9th Gen Intel Core i9-9900X
- Yes
- Intel 9th Gen Intel Core i9-9940X
- Yes
AMX Support
- Intel 9th Gen Intel Core i9-9900X
- No
- Intel 9th Gen Intel Core i9-9940X
- No
Process Node
- Intel 9th Gen Intel Core i9-9900X
- 14 nm
- Intel 9th Gen Intel Core i9-9940X
- 14 nm
Memory Support
- Intel 9th Gen Intel Core i9-9900X
- DDR4-2666, non-ECC (ECC not supported)
- Intel 9th Gen Intel Core i9-9940X
- DDR4-2666, non-ECC (ECC not supported)
Which one should you pick?
Choose 9900X if you want the higher L3 cache (19.25 MB vs 19.25 MB), the higher memory channels (4 channels vs 4 channels) and the higher PCIe lanes (44 lanes vs 44 lanes).
Choose 9940X if you want the higher L2 cache (14 MB vs 10 MB).
Price comparison
| Retailer | Intel 9th Gen Intel Core i9-9900X | Intel 9th Gen Intel Core i9-9940X |
|---|---|---|
| Newegg | View on Newegg | View on Newegg |
Disclaimer: The price and specification of the given product may differ from the actual product. Please confirm on the retailer's website before buying.