Intel Core i5-2550K

The Intel Core i5-2550K is a desktop processor built on the Sandy Bridge architecture, manufactured on a 32 nm process with 1,160 million transistors on a 216 mm² die. It offers four physical cores without hyper-threading, a base clock of 3.40 GHz, and a boost clock of 3.80 GHz. The CPU is unlocked for overclocking, uses the Intel Socket 1155 platform, and supports dual-channel DDR3 memory with a bandwidth of 25.6 GB/s. It carries a TDP of 95 W, has no integrated graphics, and was released on January 29, 2012, with a launch MSRP of $235. Its production status is end-of-life. With an average benchmark score of 1276, it sits in the 36th percentile of all CPUs, indicating a below-median performance level even among older parts.

Benchmark Performance

The benchmark results for the i5-2550K are consistent across multiple suites, though they reveal a clear performance ceiling. In Cinebench R15, the multi-core score is 359. The Cinebench R20 run yields a multi-core score of 1498 and a single-core score of 211. The more demanding Cinebench R23 produces a multi-core score of 3567 and a single-core score of 503. Geekbench reports a multi-core score of 2096 and a single-core score of 697. These numbers place the processor in the 36th percentile of all CPUs, meaning roughly two-thirds of tested processors outperform it on average.

The nearest rivals, based on average benchmark scores, are tightly clustered. The i5-2550K is 0.2% ahead of the Intel Core i5-4430S (avg score 1273), 0.2% behind the Intel Core i7-3610QE (avg score 1279), 0.3% behind the Intel Core i3-10110U (avg score 1279), and 0.4% ahead of the Intel Core i5-6400 (avg score 1271). These deltas are negligible, placing the i5-2550K in a performance band that spans less than one percentage point across four distinct product generations and market segments. The practical implication is that, for most workloads, the i5-2550K delivers performance essentially indistinguishable from those rival parts, despite differences in architecture, core count, and clock speeds. The i7-3610QE, for example, is a quad-core with hyper-threading, yet its average score is only 0.2% higher, suggesting that the i5-2550K’s lack of SMT does not heavily penalize it in the aggregated benchmark average. Similarly, the i3-10110U, a much newer dual-core with hyper-threading, matches the i5-2550K within 0.3%, underscoring the latter’s age.

Looking at specific benchmark scores, the Cinebench R23 multi-core result of 3567 is the highest raw number in the pack, but it still represents a mid-range outcome for a modern CPU. The single-core score of 503 is particularly low; many contemporary processors exceed 1500 in the same test. The Geekbench multi-core score of 2096 is likewise modest. Overall, the data shows a processor that was competitive at its launch but has been overtaken by subsequent generations. Its percentile ranking of 36 and average score of 1276 confirm that it now sits in the lower third of all tested CPUs.

Single-Thread vs Multi-Thread Behavior

The split between single-thread and multi-thread performance is telling. In Cinebench R20, the multi-core score of 1498 is 7.1 times the single-core score of 211. In Cinebench R23, the ratio is 3567 / 503 = 7.09. These ratios are far higher than the 4:1 ratio one would expect from a four-core, four-thread processor with perfect scaling. In contrast, Geekbench shows a multi-core score of 2096 against a single-core score of 697, a ratio of 3.01, which aligns closely with the core count. The discrepancy between the Cinebench and Geekbench scaling factors suggests that the Cinebench multi-core test may be more sensitive to memory bandwidth or cache behavior, while the single-core test runs at a lower effective frequency due to power or thermal limits. Alternatively, the single-core scores in Cinebench might be measured under a different turbo state than the multi-core run, but the pack does not provide such details. What can be stated is that the Cinebench multi-core results indicate a workload that benefits disproportionately from the CPU’s resources, while Geekbench reflects more conventional scaling.

For real workloads, this means that applications that rely heavily on single-thread performance—such as older games, office productivity, or lightly threaded legacy software—will see performance roughly in line with the single-core scores, which are low by modern standards. Multi-threaded tasks like video encoding, 3D rendering, or scientific simulations that scale across cores will see the multi-core scores, but the 4-thread limit caps scalability. The i5-2550K cannot take advantage of more than four concurrent threads, so any workload that can use eight or more threads will leave performance on the table. The high Cinebench scaling ratio might suggest that the multi-core test is able to extract near-ideal throughput from the four cores, but the absolute scores remain low compared to modern six- and eight-core parts.

Power and Thermals

The i5-2550K has a TDP of 95 W, which is typical for a desktop quad-core of its era. The 32 nm process and the 1,160 million transistor count indicate a moderately complex die, but the power envelope is manageable. A 95 W TDP class part generally requires a capable air cooler—one with a decent heatsink and fan—but does not necessitate liquid cooling or exotic thermal solutions. In a well-ventilated case, a stock cooler or an entry-level aftermarket tower cooler should suffice, though overclocking (the multiplier is unlocked) will increase heat output. The lack of integrated graphics means that a discrete GPU is mandatory, which also contributes to overall system power draw, but the CPU itself remains within a conventional desktop cooling range. The 216 mm² die size is modest by modern standards, and the power density is low enough that thermal throttling is unlikely under normal operating conditions, provided the cooler is not undersized.

Platform and Compatibility

The i5-2550K uses the Intel Socket 1155, a platform that was introduced with Sandy Bridge and later supported Ivy Bridge processors. Memory support is limited to DDR3, operating in dual-channel mode with a theoretical bandwidth of 25.6 GB/s. ECC memory is not supported, so this is not a platform for error-correcting workloads. The CPU provides 16 PCIe Gen 2 lanes, which is sufficient for a single graphics card but limits multi-GPU configurations and high-bandwidth NVMe storage (though NVMe was not common at the time). The unlocked multiplier (multiplierUnlocked: true) is a key feature for enthusiasts, allowing easy overclocking by raising the multiplier without altering the base clock. The part number is SR0QH.

Given its end-of-life status and the age of the Socket 1155 platform, the upgrade path is essentially nonexistent. The best CPU that can be installed on the same socket is a Core i7-3770K, but that is also a Sandy/Ivy Bridge part and would offer only a modest improvement in multi-threaded performance due to hyper-threading. The memory and PCIe capabilities are also outdated; modern platforms support DDR4/DDR5 and PCIe Gen 4 or 5. For a new build, this CPU is not a rational choice, but for a legacy system that already has a compatible motherboard, it can still function for basic tasks. The lack of integrated graphics also means that any failure of the discrete GPU renders the system unusable without a replacement.

Who Should Consider It

Based on the benchmark data, the i5-2550K is a processor for users with very specific, low-demand needs. Its 36th percentile ranking and average score of 1276 indicate that it is outclassed by the majority of CPUs currently on the market. For gaming, the single-core performance (Cinebench R23 single-core 503, Geekbench single-core 697) is sufficient for older titles or esports games that are not heavily threaded, but modern AAA games that require strong multi-core performance will likely struggle. The four threads are a hard limit; games that use more than four threads will see diminishing returns. For content creation, the multi-core scores (Cinebench R23 3567, Geekbench 2096) are too low for serious rendering or video editing; even a modern mid-range laptop CPU would outperform it. Office workloads, web browsing, and document editing are within its capabilities, but the lack of integrated graphics means a discrete GPU is always required, adding cost and power consumption.

The nearest rivals—i5-4430S, i7-3610QE, i3-10110U, and i5-6400—all sit within 0.4% of the i5-2550K in average score. This means that, in aggregate, the i5-2550K performs equivalently to those parts. However, the i3-10110U is a much newer and more efficient processor, while the i5-6400 offers a similar core count but on a newer architecture. The i7-3610QE has hyper-threading, which gives it an edge in multi-threaded workloads, though the average score does not reflect a large difference. For a user who already owns a Socket 1155 motherboard and has a compatible DDR3 kit, the i5-2550K can serve as a budget-friendly placeholder for light usage. For anyone else, the data suggests that even a modest modern processor would provide a substantial upgrade. The 95 W TDP and 32 nm process are not power-efficient by today’s standards, and the platform lacks modern I/O. In short, the i5-2550K is a legacy part that is best suited for retro builds, home servers with low computational demands, or as a temporary CPU while a more capable replacement is sourced. Its benchmark scores, while internally consistent, place it firmly in the lower quartile of all CPUs, and its platform limitations further restrict its usefulness in 2025 and beyond.