Intel Core i5-1250P vs Intel Core i9-9900KS Comparison

The Verdict

The recorded data sets these two processors apart by a clear but narrow margin. Across every shared benchmark, the Intel Core i9-9900KS finishes ahead of the Intel Core i5-1250P. The i9-9900KS wins all six head-to-head Cinebench tests, with margins ranging from 4.7% to 5.1%. Its average benchmark score is 4738, which places it in the 59th percentile of all CPUs in the database. The i5-1250P averages 4515, sitting at the 58th percentile. The difference in percentile ranking is just one point, but the benchmark consistency favors the older desktop chip.

The i9-9900KS is the choice for anyone prioritizing raw multi-threaded and single-threaded compute in a desktop environment. Its 5.0 GHz boost clock, 16 MB of shared L3 cache, and 127 W TDP deliver a measurable edge in every Cinebench iteration. The i5-1250P, by contrast, is a mobile processor with a 28 W TDP, 12 cores, and 12 MB of shared L3 cache. It loses each Cinebench round by roughly 5%, which is a modest gap but a consistent one.

For mobile users, the i5-1250P is the only realistic option given its BGA 1744 socket and integrated Iris Xe 80EU graphics. The i9-9900KS uses an LGA 1151 socket and is marked end-of-life, so new desktop builds would require existing platform availability. The i5-1250P remains active in production, making it the better pick for current laptop designs or compact systems.

The i9-9900KS also holds a small but meaningful lead in single-core performance. In Cinebench R23 single-core, it scores 2321 versus 2203 for the i5-1250P, a 5.1% gap. In R20 single-core, 974 versus 925, a 5% gap. These numbers suggest that for lightly threaded workloads, the older chip still has a slight edge due to its higher boost clock and older but simpler architecture.

The verdict is straightforward: the i9-9900KS wins on raw performance, the i5-1250P wins on mobility and platform longevity. Neither chip dominates by a wide margin, but the data consistently favors the i9-9900KS in compute-heavy tasks.

FAQ

Q: Which processor has a higher average benchmark score?

A: The Intel Core i9-9900KS has an average benchmark score of 4738, while the Intel Core i5-1250P averages 4515. The i9-9900KS also ranks in the 59th percentile of all CPUs, versus the 58th percentile for the i5-1250P.

Q: How do the two chips compare in Cinebench R23 multi-core performance?

A: The i9-9900KS scores 16446 in Cinebench R23 multi-core, while the i5-1250P scores 15610. That is a 5.1% advantage for the i9-9900KS.

Q: What is the TDP difference between these processors?

A: The i5-1250P has a 28 W TDP, typical for a mobile chip. The i9-9900KS has a 127 W TDP, indicating a desktop-class power envelope. This explains part of the performance gap.

Q: Do both processors support the same memory types?

A: No. The i5-1250P supports DDR4 and DDR5 memory, while the i9-9900KS supports only DDR4. Both use dual-channel memory buses, but the i9-9900KS has a recorded memory bandwidth of 42.7 GB/s, a figure not listed for the i5-1250P.

Q: Are both processors unlocked for overclocking?

A: The i9-9900KS has an unlocked multiplier, meaning it can be overclocked. The i5-1250P does not have an unlocked multiplier, so its clock speeds are fixed by the platform.

Q: Which processor has more cores?

A: The i5-1250P has 12 cores and 16 threads, while the i9-9900KS has 8 cores and 16 threads. Despite having more cores, the i5-1250P still trails the i9-9900KS in multi-threaded Cinebench scores.

Architecture Differences

The two processors come from different architectural eras. The i5-1250P is built on Alder Lake, using Intel's 10 nm process node, and is part of the Alder Lake-P family. The i9-9900KS uses the older Coffee Lake architecture, built on a 14 nm process node, and belongs to the Coffee Lake-R refresh line. This process node difference is significant: the i5-1250P packs more transistors into a smaller space, but the i9-9900KS compensates with higher clock speeds and a more straightforward core design.

The i5-1250P features 12 cores and 16 threads, a hybrid arrangement that Alder Lake introduced. The i9-9900KS has 8 cores and 16 threads, a more conventional design where every core is identical. The i5-1250P uses 1.25 MB of L2 cache per core, while the i9-9900KS uses 256 KB per core. For L1 cache, the i5-1250P has 80 KB per core versus 64 KB per core for the i9-9900KS. However, the i9-9900KS has a larger shared L3 cache at 16 MB, compared to 12 MB for the i5-1250P.

The i5-1250P integrates Iris Xe 80EU graphics, a more capable integrated GPU than the UHD 630 found in the i9-9900KS. The i5-1250P also supports PCIe Gen 4 with 20 lanes, while the i9-9900KS uses PCIe Gen 3 with 16 lanes. The i5-1250P supports both DDR4 and DDR5 memory, while the i9-9900KS is limited to DDR4. The i9-9900KS has a recorded memory bandwidth of 42.7 GB/s; no such figure is listed for the i5-1250P.

The i9-9900KS has a die size of 180 mm², while the i5-1250P has a die size of 217 mm². This is notable because the i5-1250P uses a smaller process node but a larger physical die, likely due to the integrated graphics and additional cores. The i9-9900KS was released in October 2019, while the i5-1250P arrived in February 2022. The i9-9900KS is end-of-life, while the i5-1250P remains active in production.

Specification Differences

The base clock differs significantly: the i9-9900KS runs at 4.00 GHz, while the i5-1250P runs at 1.70 GHz. The boost clock also favors the i9-9900KS at 5.00 GHz versus 4.40 GHz for the i5-1250P. This 0.6 GHz boost advantage is a primary reason for the i9-9900KS's single-core wins.

The TDP is another major differentiator. The i5-1250P is rated at 28 W, making it suitable for thin laptops. The i9-9900KS is rated at 127 W, a typical desktop figure. The socket types are incompatible: the i5-1250P uses Intel BGA 1744, while the i9-9900KS uses Intel Socket 1151.

The i5-1250P has 12 cores and 16 threads, while the i9-9900KS has 8 cores and 16 threads. The cache hierarchy differs, as detailed earlier. The i9-9900KS has a memory bandwidth of 42.7 GB/s, which is not listed for the i5-1250P. The i9-9900KS supports only DDR4, while the i5-1250P supports DDR4 and DDR5.

The i9-9900KS has an unlocked multiplier, while the i5-1250P does not. The i9-9900KS also has a launch MSRP of $513; the i5-1250P has no recorded launch MSRP. The i9-9900KS uses PCIe Gen 3 with 16 lanes, while the i5-1250P uses PCIe Gen 4 with 20 lanes. The integrated graphics differ: Iris Xe 80EU for the i5-1250P, UHD 630 for the i9-9900KS.

The production status is a key practical difference: the i9-9900KS is end-of-life, while the i5-1250P is active. The i9-9900KS was released in 2019, the i5-1250P in 2022.

Head-to-Head Benchmarks

The head-to-head data covers six Cinebench tests, and the i9-9900KS wins all of them. In Cinebench R15 multi-core, the i9-9900KS scores 1657 versus 1573 for the i5-1250P, a 5.1% difference. In R15 single-core, 233 versus 222, a 4.7% gap. These are the smallest margins in the set.

In Cinebench R20 multi-core, the i9-9900KS scores 6907 versus 6556, a 5.1% advantage. In R20 single-core, 974 versus 925, a 5% gap. The pattern continues in Cinebench R23: multi-core 16446 versus 15610, a 5.1% difference, and single-core 2321 versus 2203, also 5.1%.

The consistency is striking. Every multi-core test shows a 5.1% lead for the i9-9900KS, and every single-core test shows between 4.7% and 5.1% lead. This suggests the i9-9900KS has a fundamental performance advantage that scales across workloads, not just in one specific test.

The i5-1250P never wins a head-to-head benchmark in this set. Its 12 cores do not overcome the i9-9900KS's higher clock speeds and larger L3 cache. The i9-9900KS also has a higher average benchmark score of 4738 versus 4515, and a higher percentile rank of 59 versus 58.

It is worth remembering the i5-1250P's nearest rivals include the Intel Core i7-12700TE with an average score of 4513 (0% delta) and the AMD Ryzen Embedded V2748 at 4532 (-0.4%). The i9-9900KS's nearest rivals include the Intel Core i7-6950X at 4734 (0.1% delta) and the Intel Core i9-10900E at 4708 (0.6%). These rival comparisons place both chips in similar performance tiers, but the i9-9900KS sits slightly higher.

Where Each One Wins

The i9-9900KS wins in every measured compute benchmark. If the task is multi-threaded rendering, video encoding, or any CPU-bound workload that scales across cores, the i9-9900KS delivers a 5.1% advantage in Cinebench R23 multi-core. Its 5.0 GHz boost clock also gives it a slight edge in single-threaded tasks, as seen in the 4.7% to 5.1% single-core wins. For desktop users who already have an LGA 1151 platform or can source one, the i9-9900KS is the stronger performer.

The i5-1250P wins in practical mobility and platform flexibility. Its 28 W TDP makes it suitable for battery-powered devices, while the i9-9900KS's 127 W TDP requires a desktop cooling solution. The i5-1250P supports DDR5 memory, which is not available on the i9-9900KS. Its PCIe Gen 4 support with 20 lanes offers more modern connectivity options. The integrated Iris Xe 80EU graphics are more capable than the UHD 630, making the i5-1250P better for light gaming or media playback without a discrete GPU.

The i5-1250P also wins on availability. It is an active production part, while the i9-9900KS is end-of-life. For new system builds, the i5-1250P is easier to source in current mobile platforms. The i9-9900KS, despite its performance lead, is a legacy part.

The i9-9900KS wins on overclocking potential due to its unlocked multiplier, a feature the i5-1250P lacks. However, the i5-1250P's non-unlocked multiplier is typical for mobile chips, where thermal limits are stricter.

In summary: the i9-9900KS is the winner for raw compute, single-threaded responsiveness, and overclocking. The i5-1250P is the winner for mobile use, modern memory support, integrated graphics quality, and ongoing availability. The performance gap is real but modest, about 5% across the board, so the choice depends more on platform and power requirements than on absolute speed.