Ultra 7 255HX vs i9-9900KS
Aggregate performance score
Core Ultra 7 255HX outperforms Core i9-9900KS by a whopping 157% based on our aggregate benchmark results.
Contents
Primary details
Comparing processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 806 | 204 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 8.74 | no data |
| Market segment | Desktop processor | Laptop |
| Series | Intel Core i9 | no data |
| Power efficiency | 3.68 | 21.85 |
| Designer | Intel | Intel |
| Manufacturer | Intel | TSMC |
| Architecture codename | Coffee Lake-R (2018−2019) | Arrow Lake-HX (2025) |
| Release date | 28 October 2019 (6 years ago) | 13 January 2025 (less than a year ago) |
| Launch price (MSRP) | $513 | no data |
Cost-effectiveness evaluation
Performance per price, higher is better.
Performance to price scatter graph
Detailed specifications
Core i9-9900KS and Core Ultra 7 255HX basic parameters such as number of cores, number of threads, base frequency and turbo boost clock, lithography, cache size and multiplier lock state. These parameters indirectly say of CPU speed, though for more precise assessment you have to consider their test results.
| Physical cores | 8 (Octa-Core) | 20 (Icosa-Core) |
| Performance-cores | no data | 8 |
| Efficient-cores | no data | 12 |
| Threads | 16 | 20 |
| Base clock speed | 4 GHz | 2.4 GHz |
| Boost clock speed | 5 GHz | 5.2 GHz |
| Bus type | DMI 3.0 | no data |
| Bus rate | 4 × 8 GT/s | no data |
| Multiplier | 40 | no data |
| L1 cache | 64 KB (per core) | 192 KB (per core) |
| L2 cache | 256 KB (per core) | 3 MB (per core) |
| L3 cache | 16 MB (shared) | 30 MB (shared) |
| Chip lithography | 14 nm | 3 nm |
| Die size | 180 mm2 | 243 mm2 |
| Maximum core temperature | 100 °C | no data |
| Maximum case temperature (TCase) | 72 °C | no data |
| Number of transistors | no data | 17,800 million |
| 64 bit support | + | + |
| Windows 11 compatibility | + | no data |
| Unlocked multiplier | + | + |
Compatibility
Information on Core i9-9900KS and Core Ultra 7 255HX compatibility with other computer components: motherboard (look for socket type), power supply unit (look for power consumption) etc. Useful when planning a future computer configuration or upgrading an existing one. Note that power consumption of some processors can well exceed their nominal TDP, even without overclocking. Some can even double their declared thermals given that the motherboard allows to tune the CPU power parameters.
| Number of CPUs in a configuration | 1 (Uniprocessor) | 1 |
| Socket | FCLGA1151 | FCBGA2114 |
| Power consumption (TDP) | 127 Watt | 55 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Core i9-9900KS and Core Ultra 7 255HX. You'll probably need this information if you require some particular technology.
| Instruction set extensions | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2 | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2 |
| AES-NI | + | + |
| AVX | + | + |
| vPro | + | + |
| Enhanced SpeedStep (EIST) | + | + |
| Speed Shift | no data | + |
| Turbo Boost Technology | 2.0 | 2.0 |
| Hyper-Threading Technology | + | - |
| TSX | + | - |
| Idle States | + | + |
| Thermal Monitoring | + | + |
| SIPP | + | - |
| Turbo Boost Max 3.0 | no data | + |
| Deep Learning Boost | - | + |
| Supported AI Software Frameworks | - | OpenVINO™, WindowsML, DirectML, ONNX RT, WebNN |
Security technologies
Core i9-9900KS and Core Ultra 7 255HX technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | + |
| EDB | + | + |
| MPX | + | - |
| Identity Protection | + | - |
| SGX | Yes with Intel® ME | no data |
| OS Guard | + | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Core i9-9900KS and Core Ultra 7 255HX are enumerated here.
| AMD-V | + | - |
| VT-d | + | + |
| VT-x | + | + |
| EPT | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Core i9-9900KS and Core Ultra 7 255HX. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR4 | DDR5-6400 |
| Maximum memory size | 128 GB | 256 GB |
| Max memory channels | 2 | 2 |
| Maximum memory bandwidth | 42.671 GB/s | no data |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | Intel UHD Graphics 630 | Intel® Graphics |
| Max video memory | 64 GB | no data |
| Quick Sync Video | + | + |
| Clear Video | + | no data |
| Clear Video HD | + | no data |
| Graphics max frequency | 1.2 GHz | 1.85 GHz |
| InTru 3D | + | no data |
Graphics interfaces
Available interfaces and connections of Core i9-9900KS and Core Ultra 7 255HX integrated GPUs.
| Number of displays supported | 3 | 4 |
Graphics image quality
Maximum display resolutions supported by Core i9-9900KS and Core Ultra 7 255HX integrated GPUs, including resolutions over different interfaces.
| 4K resolution support | + | no data |
| Max resolution over HDMI 1.4 | 4096 x 2304@24Hz | 4096 x 2304 @ 60Hz (HDMI 2.1 TMDS)7680 x 4320 @ 60Hz (HDMI 2.1 FRL) |
| Max resolution over eDP | 4096 x 2304@60Hz | 3840 x 2400 @ 120Hz |
| Max resolution over DisplayPort | 4096 x 2304@60Hz | 7680 x 4320 @ 60Hz |
Graphics API support
APIs supported by Core i9-9900KS and Core Ultra 7 255HX integrated GPUs, sometimes API versions are included.
| DirectX | 12 | 12 |
| OpenGL | 4.5 | 4.5 |
Peripherals
Specifications and connection of peripherals supported by Core i9-9900KS and Core Ultra 7 255HX.
| PCIe version | 3.0 | 5.0 and 4.0 |
| PCI Express lanes | 16 | 24 |
Synthetic benchmarks
Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.
Combined synthetic benchmark score
This is our combined benchmark performance rating.
Passmark
Passmark CPU Mark is a widespread benchmark, consisting of 8 different types of workload, including integer and floating point math, extended instructions, compression, encryption and physics calculation. There is also one separate single-threaded scenario measuring single-core performance. Other than that, Passmark measures multi-core performance.
Cinebench 10 32-bit single-core
Cinebench R10 is an ancient ray tracing benchmark for processors by Maxon, authors of Cinema 4D. Its single core version uses just one CPU thread to render a futuristic looking motorcycle.
Cinebench 10 32-bit multi-core
Cinebench Release 10 Multi Core is a variant of Cinebench R10 using all the processor threads. Possible number of threads is limited by 16 in this version.
Cinebench 15 64-bit multi-core
Cinebench Release 15 Multi Core is a variant of Cinebench R15 which uses all the processor threads.
Cinebench 15 64-bit single-core
Cinebench R15 (standing for Release 15) is a benchmark made by Maxon, authors of Cinema 4D. It was superseded by later versions of Cinebench, which use more modern variants of Cinema 4D engine. The Single Core version (sometimes called Single-Thread) only uses a single processor thread to render a room full of reflective spheres and light sources.
TrueCrypt AES
TrueCrypt is a discontinued piece of software that was widely used for on-the-fly-encryption of disk partitions, now superseded by VeraCrypt. It contains several embedded performance tests, one of them being TrueCrypt AES, which measures data encryption speed using AES algorithm. Result is encryption speed in gigabytes per second.
x264 encoding pass 2
x264 Pass 2 is a slower variant of x264 video compression that produces a variable bit rate output file, which results in better quality since the higher bit rate is used when it is needed more. Benchmark result is still measured in frames per second.
x264 encoding pass 1
x264 version 4.0 is a video encoding benchmark uses MPEG 4 x264 compression method to compress a sample HD (720p) video. Pass 1 is a faster variant that produces a constant bit rate output file. Its result is measured in frames per second, which means how many frames of the source video file were encoded per second.
Pros & cons summary
| Performance score | 11.00 | 28.24 |
| Recency | 28 October 2019 | 13 January 2025 |
| Physical cores | 8 | 20 |
| Threads | 16 | 20 |
| Chip lithography | 14 nm | 3 nm |
| Power consumption (TDP) | 127 Watt | 55 Watt |
Ultra 7 255HX has a 156.7% higher aggregate performance score, an age advantage of 5 years, 150% more physical cores and 25% more threads, a 366.7% more advanced lithography process, and 130.9% lower power consumption.
The Intel Core Ultra 7 255HX is our recommended choice as it beats the Intel Core i9-9900KS in performance tests.
Note that Core i9-9900KS is a desktop processor while Core Ultra 7 255HX is a notebook one.
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