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Intel Core i9-9900X X-series

Intel Core i9-9900X X-Series: Review and Practical Tips for Building in 2025

Relevance, Performance, and Selection Nuances for Enthusiasts and Professionals

1. Key Specifications: Architecture and Performance

Codename and Process Technology

The Intel Core i9-9900X X-series, based on the SkyLake architecture, was released using a 14nm process technology. Although 14nm is considered outdated by 2025, Intel has optimized this platform for the niche of high-performance desktops. It is one of the last processors in the X-series before the company's transition to hybrid architectures (Big.Little).

Cores, Threads, and Clock Speeds

- 10 cores / 20 threads — ideal for multi-threaded tasks.

- Base clock speed: 3.5 GHz, maximum turbo mode — 4.5 GHz.

- L3 cache: 19.25 MB.

Performance

- Geekbench 6: Single-Core — 1361, Multi-Core — 7874.

- In rendering tests (Blender, Cinebench R23), it shows results comparable to the AMD Ryzen 9 5900X but lags behind the newer Ryzen 7000/8000 series.

- In games (Cyberpunk 2077, Starfield), FPS is 5-10% lower than modern counterparts due to the lack of PCIe 5.0 and DDR5.

Key Features

- Support for Intel Turbo Boost Max 3.0 for automatic overclocking of active cores.

- 40 PCIe 3.0 lanes — ample for multiple GPUs and NVMe drives.

- Optane Memory Ready — enhances performance with HDDs.

2. Compatible Motherboards: Sockets and Chipsets

Socket LGA 2066

The processor requires motherboards with the LGA 2066 socket. Popular models include:

- ASUS ROG Rampage VI Extreme (price: ~$350) — top choice for overclocking.

- Gigabyte X299 AORUS Ultra (~$280) — a balance of price and functionality.

Chipsets

- Intel X299 — the only option.

Features:

- Support for 4-Way SLI/CrossFire.

- Up to 8 SATA III ports and 3 M.2 sockets (PCIe 3.0 x4).

- No USB4 or Thunderbolt 4 (external controllers required).

Selection Tips

- For overclocking: boards with at least 12 VRM phases and heatsinks (e.g., MSI X299 Gaming Pro Carbon AC).

- For workstations: models with 10 Gb Ethernet and Wi-Fi 6 (ASUS WS X299 Sage).

3. Supported Memory: DDR4 and Its Potential

- Memory type: only DDR4 (DDR5 not supported).

- Max frequency: up to 3200 MHz (with XMP profiles).

- Configurations: 4-channel mode — for maximum bandwidth.

Recommendations

- Optimal capacity: 32-64 GB (4x8 GB or 4x16 GB).

- Example: Corsair Vengeance LPX 3200 MHz CL16 kit (~$120 for 32 GB).

4. Power Supplies: Power Calculation

Processor TDP: 165 W, but peak power can reach 200 W when overclocked.

Recommendations

- Minimum: 650 W (for a system with an RTX 4070 level GPU).

- Ideal: 750-850 W (with a buffer for upgrades and overclocking).

- Certification: 80+ Gold or Platinum (Corsair RM850x, Seasonic PRIME GX-750).

Example Build

- CPU: i9-9900X (165 W).

- GPU: NVIDIA RTX 4080 (320 W).

- Total: 165 + 320 + 100 W (other) = 585 W. A 750 W PSU will cover the load comfortably.

5. Pros and Cons of the Processor

Pros

- High multi-threaded performance for rendering and encoding.

- Support for 4-channel DDR4 memory.

- Wide compatibility with PCIe devices.

Cons

- Outdated 14nm process: higher power consumption and heat output.

- Lack of PCIe 4.0/5.0 and DDR5.

- Price (~$450) is close to the new AMD Ryzen 9 7900 ($499).

6. Use Cases

Work Tasks

- 3D Rendering: In Blender, the processor achieves 78% of the speed of the Ryzen 9 7950X.

- Video Editing: 4K rendering in Premiere Pro takes 12-15 minutes (compared to 8-10 minutes on the Ryzen 9 7900).

Gaming

- At Full HD (RTX 4080): 144+ FPS in CS2, 110 FPS in Cyberpunk 2077 (Ultra).

- At 4K: the GPU becomes the bottleneck; the difference with new CPUs is minimal.

Multimedia

- Streaming (OBS + game) without lag, thanks to 20 threads.

7. Comparison with Competitors

- AMD Ryzen 9 7900 ($499):

- 12 cores / 24 threads, 5nm, DDR5, PCIe 5.0.

- Multi-Core in Geekbench 6: ~10500.

- Intel Core i7-14700K ($410):

- 20 cores (8P+12E), DDR5, but with less cache.

Conclusion: i9-9900X is only worthwhile when purchased used or bundled with an X299 motherboard.

8. Practical Assembly Tips

- Cooling:

- Minimum: Air cooler Noctua NH-D15 (~$90).

- Optimal: Liquid cooling Arctic Liquid Freezer II 360 (~$120).

- Case: with good airflow (Lian Li Lancool III).

- BIOS Optimization:

- Disable unnecessary peripheral controllers for energy savings.

- Configure XMP for memory.

9. Final Conclusion: Who is the i9-9900X Suitable For?

This processor is relevant for:

1. Professionals needing stable multi-threaded performance without overpaying for DDR5.

2. Enthusiasts upgrading old systems on X299.

3. Streamers combining gaming and video encoding.

Why not to get it in 2025?

If you are building a system from scratch — it's better to choose a platform with DDR5 and PCIe 5.0 (AMD AM5 or Intel LGA 1851). However, the i9-9900X remains a budget solution for niche tasks.

Prices and specifications are current as of April 2025. Check compatibility of components before purchase!

Basic

Label Name

Intel

Platform

Desktop

Launch Date

October 2018

Model Name

The Intel processor number is just one of several factors - along with processor brand, system configurations, and system-level benchmarks - to be considered when choosing the right processor for your computing needs.

i9-9900X

Code Name

SkyLake

CPU Specifications

Total Cores

Cores is a hardware term that describes the number of independent central processing units in a single computing component (die or chip).

Total Threads

Where applicable, Intel® Hyper-Threading Technology is only available on Performance-cores.

Basic Frequency

3.50 GHz

Max Turbo Frequency

Max Turbo Frequency is the maximum single-core frequency at which the processor is capable of operating using Intel® Turbo Boost Technology and, if present, Intel® Turbo Boost Max Technology 3.0 and Intel® Thermal Velocity Boost. Frequency is typically measured in gigahertz (GHz), or billion cycles per second.

4.40 GHz

Intel Turbo Boost Max Technology 3.0 Frequency

Intel® Turbo Boost Max Technology 3.0 identifies the best performing core(s) on a processor and provides increased performance on those cores through increasing frequency as needed by taking advantage of power and thermal headroom. Intel® Turbo Boost Max Technology 3.0 frequency is the clock frequency of the CPU when running in this mode.

4.50 GHz

Intel Turbo Boost Max Technology 3.0

Yes

Intel Hyper-Threading Technology

Intel® Hyper-Threading Technology (Intel® HT Technology) delivers two processing threads per physical core. Highly threaded applications can get more work done in parallel, completing tasks sooner.

Yes

Intel Turbo Boost Technology

Intel® Turbo Boost Technology dynamically increases the processor's frequency as needed by taking advantage of thermal and power headroom to give you a burst of speed when you need it, and increased energy efficiency when you don’t.

2.0

CPU Socket

The socket is the component that provides the mechanical and electrical connections between the processor and motherboard.

FCLGA2066

Technology

Lithography refers to the semiconductor technology used to manufacture an integrated circuit, and is reported in nanometer (nm), indicative of the size of features built on the semiconductor.

14 nm

TDP

165 W

Max. Operating Temperature

Junction Temperature is the maximum temperature allowed at the processor die.

92°C

PCI Express Version

PCI Express Revision is the supported version of the PCI Express standard. Peripheral Component Interconnect Express (or PCIe) is a high-speed serial computer expansion bus standard for attaching hardware devices to a computer. The different PCI Express versions support different data rates.

3.0

Number of PCI Express Lanes

A PCI Express (PCIe) lane consists of two differential signaling pairs, one for receiving data, one for transmitting data, and is the basic unit of the PCIe bus. Max # of PCI Express Lanes is the total number of supported lanes.

Intel 64

Intel® 64 architecture delivers 64-bit computing on server, workstation, desktop and mobile platforms when combined with supporting software.¹ Intel 64 architecture improves performance by allowing systems to address more than 4 GB of both virtual and physical memory.

Yes

Memory Specifications

Memory Type

Intel® processors come in four different types: Single Channel, Dual Channel, Triple Channel, and Flex Mode. Maximum supported memory speed may be lower when populating multiple DIMMs per channel on products that support multiple memory channels.

DDR4-2666

Max Memory Size

Max memory size refers to the maximum memory capacity supported by the processor.

128 GB

Memory Channels

The number of memory channels refers to the bandwidth operation for real world application.

Bus Speed

8 GT/s

Max Memory Bandwidth

Max Memory bandwidth is the maximum rate at which data can be read from or stored into a semiconductor memory by the processor (in GB/s).

85 GB/s

ECC Memory Supported

ECC Memory Supported indicates processor support for Error-Correcting Code memory. ECC memory is a type of system memory that can detect and correct common kinds of internal data corruption. Note that ECC memory support requires both processor and chipset support.

Miscellaneous

Intel Virtualization Technology for Directed I/O (VT-d)

Intel® Virtualization Technology for Directed I/O (VT-d) continues from the existing support for IA-32 (VT-x) and Itanium® processor (VT-i) virtualization adding new support for I/O-device virtualization. Intel VT-d can help end users improve security and reliability of the systems and also improve performance of I/O devices in virtualized environments.

Yes

Intel Virtualization Technology (VT-x)

Intel® Virtualization Technology (VT-x) allows one hardware platform to function as multiple “virtual” platforms. It offers improved manageability by limiting downtime and maintaining productivity by isolating computing activities into separate partitions.

Yes

Intel Standard Manageability (ISM)

Intel® Standard Manageability is the manageability solution for Intel vPro® Essentials platforms and is a subset of Intel® AMT with out-of-band management over Ethernet and Wi-Fi, but no KVM or new life cycle management features.

Intel® SSE4.1 | Intel® SSE4.2 | Intel® AVX2 | Intel® AVX-512

Number of AVX-512 FMA Units

Enhanced Intel SpeedStep Technology

Enhanced Intel SpeedStep® Technology is an advanced means of enabling high performance while meeting the power-conservation needs of mobile systems. Conventional Intel SpeedStep® Technology switches both voltage and frequency in tandem between high and low levels in response to processor load. Enhanced Intel SpeedStep® Technology builds upon that architecture using design strategies such as Separation between Voltage and Frequency Changes, and Clock Partitioning and Recovery.

Yes

Execute Disable Bit

Execute Disable Bit is a hardware-based security feature that can reduce exposure to viruses and malicious-code attacks and prevent harmful software from executing and propagating on the server or network.

Yes

Cache

CPU Cache is an area of fast memory located on the processor. Intel® Smart Cache refers to the architecture that allows all cores to dynamically share access to the last level cache.

19.25 MB Intel® Smart Cache

Intel AES New Instructions

Intel® AES New Instructions (Intel® AES-NI) are a set of instructions that enable fast and secure data encryption and decryption. AES-NI are valuable for a wide range of cryptographic applications, for example: applications that perform bulk encryption/decryption, authentication, random number generation, and authenticated encryption.

Yes

Benchmarks

Geekbench 6

Single Core Score

1361

Geekbench 6

Multi Core Score

7874

Geekbench 5

Single Core Score

1113

Geekbench 5

Multi Core Score

10176

Compared to Other CPU

Geekbench 6 Single Core

Core i3-10305

1447 +6.3%

Xeon Gold 6230

1393 +2.4%

Core i9-9900X X-series

1361

EPYC 7302

1318 -3.2%

Core i5-4670K

1275 -6.3%

Geekbench 6 Multi Core

Xeon Gold 6142

8730 +10.9%

Core i7-11850HE

8335 +5.9%

Core i9-9900X X-series

7874

Core i3-12100F

7425 -5.7%

Xeon E7-8880 v3

6961 -11.6%

Geekbench 5 Single Core

Xeon W-10885M

1162 +4.4%

Ryzen Threadripper PRO 3975WX

1130 +1.5%

Core i9-9900X X-series

1113

Pentium Gold 7505

1090 -2.1%

Xeon E3-1230 v6

1068 -4%

Geekbench 5 Multi Core

Xeon Gold 6346

12084 +18.8%

Core i9-10900K

11000 +8.1%

Core i9-9900X X-series

10176

Ryzen 9 3950X

9500 -6.6%

Ryzen 9 6900HX

8937 -12.2%