Intel Core i5-655K

The Intel Core i5-655K is a desktop processor from Intel's Clarkdale generation, built on a 32 nm process with 382 million transistors on an 81 mm² die. It combines two physical cores with four threads, running at a base clock of 3.20 GHz and a boost clock of 3.47 GHz. With a TDP of 73 W and an unlocked multiplier, it was positioned as an overclockable entry point for the Intel Socket 1156 platform. Released on May 29, 2010, with a launch MSRP of $216, it has since been marked end-of-life, and its benchmark scores place it in the 13th percentile of all CPUs in the database.

Platform and Compatibility

The i5-655K is built for Intel Socket 1156, the socket associated with the Westmere/Clarkdale architecture. It supports DDR3 memory in a dual-channel configuration, with a memory bandwidth of 21.3 GB/s. The integrated memory controller does not support ECC memory, limiting its use in error-correcting server or workstation environments. PCIe connectivity is provided via 16 Gen 2 lanes from the CPU, which is sufficient for a single discrete graphics card or a few expansion cards. The processor also includes HD Graphics, making it a self-contained solution for basic display output without a separate GPU. As an end-of-life product, the Socket 1156 platform is no longer actively produced, and the 32 nm process node and 81 mm² die size reflect the technology of that era. The part number is SLBXL, and the multiplier is unlocked, allowing enthusiasts to push clock speeds beyond the stock 3.20 GHz base and 3.47 GHz boost. The memory controller's dual-channel design and 21.3 GB/s bandwidth are modest by modern standards, but they were typical for the platform's generation.

Who Should Consider It

The i5-655K's benchmark results indicate that it is a low-performance processor by current standards. Its overall percentile of 13 means it outperforms only 13% of all CPUs in the database, so it is not suitable for demanding tasks such as modern gaming, video editing, or 3D rendering. In Cinebench R23, it scores 1714 in multi-core and 242 in single-core; the R20 tests yield 719 multi-core and 101 single-core. These numbers suggest that basic office applications, web browsing, and light productivity tasks are within its capabilities, but anything that requires sustained multi-threaded execution will strain the processor. The 2-core/4-thread configuration allows for some parallel processing, yet the low single-core scores (101 in R20, 242 in R23) mean that even single-threaded applications will feel sluggish compared to modern chips. For users who already own a Socket 1156 motherboard, the 655K could serve as a budget-friendly upgrade from a weaker dual-core, but for new builds, the end-of-life status and low performance make it a poor choice. The integrated HD Graphics eliminates the need for a discrete GPU in non-gaming systems, which might appeal to a basic office or home-theater PC, but the processor's age and lack of modern instruction sets limit its future-proofing.

Benchmark Performance

The i5-655K's average benchmark score is 590, which places it in a cluster of similarly performing processors. Its nearest rivals include the Intel Core i5-2415M and AMD Phenom II X4 810, both with an average score of 590 and a delta of 0%. The Intel Pentium G3250 and Intel Xeon E5420 each score 591, giving them a 0.2% advantage over the 655K. These deltas are negligible, indicating that the 655K performs virtually identically to a mobile dual-core i5 and a desktop quad-core Phenom II, while trailing the Pentium and Xeon by a hair. In Cinebench R15 multi-core, the 655K scores 172; in R20, it scores 719 multi-core and 101 single-core; and in R23, it scores 1714 multi-core and 242 single-core. The multi-core scores show that the dual-core with four threads can produce throughput comparable to a four-core Phenom II, likely due to higher clock speeds and a more efficient architecture. However, the single-core scores are low, reflecting the older Westmere design and the lack of modern enhancements like AVX2. The benchmark data suggests that the 655K is a balanced performer for its era, but it has not aged well against newer processors.

FAQ

Q: What is the launch MSRP of the Intel Core i5-655K?

A: The launch MSRP was $216.

Q: Does the i5-655K support ECC memory?

A: No, ECC memory is not supported.

Q: What is the TDP of this processor?

A: The TDP is 73 W.

Q: Is the multiplier unlocked?

A: Yes, the multiplier is unlocked, allowing overclocking.

Q: What integrated graphics does it include?

A: It includes HD Graphics.

Q: How many PCIe lanes does it provide?

A: It provides 16 PCIe Gen 2 lanes from the CPU.

How It Compares

Against the Intel Core i5-2415M: The 655K and the 2415M have identical average benchmark scores of 590, with a 0% delta. The 2415M is a mobile processor, while the 655K is desktop, yet their aggregate performance is exactly the same. This implies that the 655K's higher clock speeds (3.20 GHz base, 3.47 GHz boost) compensate for the 2415M's potentially more efficient architecture or lower power draw. In practice, the two would deliver similar user experience in most workloads.

Against the AMD Phenom II X4 810: The Phenom II X4 810 also ties the 655K with a 590 average score and 0% delta. The Phenom has four physical cores, but likely lower clock speeds and an older architecture. The fact that the 655K matches a quad-core in the aggregated benchmark suggests that its two cores with four threads are sufficient to keep pace in multi-threaded tests, at least within the benchmark suite used. This is a notable result for a dual-core part.

Against the Intel Pentium G3250: The Pentium G3250 edges out the 655K by 0.2%, with an average score of 591 versus 590. The G3250 is a newer dual-core without Hyper-Threading, yet it manages a slightly higher score. This indicates that the 655K's extra threads do not fully compensate for its older architecture. The 655K's unlocked multiplier and integrated graphics are its main advantages, but in raw benchmark performance, the Pentium is marginally ahead.

Against the Intel Xeon E5420: The Xeon E5420 also posts a 591 average score, a 0.2% delta over the 655K. The E5420 is a server-oriented quad-core from an older generation, but it still outperforms the 655K by a tiny margin. This suggests that the 655K's higher clock speeds and newer process node are not enough to overcome the core-count advantage of the Xeon in this benchmark. The differences are within measurement error, so the two are effectively comparable.

Single-Thread vs Multi-Thread Behavior

The i5-655K exhibits a clear split between its single-thread and multi-thread performance. In Cinebench R20, it scores 101 single-core and 719 multi-core; in R23, the scores are 242 single-core and 1714 multi-core. The multi-core scores are significantly higher, indicating that the two cores and four threads can be effectively utilized by parallel workloads. However, the single-core scores are low, reflecting the modest clock speed (3.20 GHz base, 3.47 GHz boost) and the older Westmere architecture. This means that applications that rely heavily on a single thread, such as many older games, some productivity tools, and certain scripting workloads, will see limited performance. Conversely, tasks that can spread work across multiple threads, like video encoding, 3D rendering, and scientific simulations, will benefit from the four-thread execution. The benchmark comparisons show that the 655K can match a quad-core Phenom II in multi-threaded tests, but its single-thread performance is a bottleneck for interactive use. For a system used primarily for multi-threaded batch processing, the 655K may still be serviceable, but for responsive everyday computing, its single-thread limitations will be apparent.

Power and Thermals

The i5-655K has a TDP of 73 W, which is moderate for a desktop processor of its generation. This TDP class implies that a standard air cooler designed for Socket 1156 would be sufficient to dissipate the heat generated under normal operation. The 32 nm process and 81 mm² die size contribute to a relatively low heat density, and the integrated HD Graphics adds to the thermal load but remains within the 73 W envelope. Because the multiplier is unlocked, overclocking is possible, which would increase power draw and heat output beyond the stock TDP. Enthusiasts who choose to overclock would need a more robust cooling solution, though the exact requirements are not specified in the data. The processor's end-of-life status means that new coolers for modern sockets may not be compatible with Socket 1156, but the 73 W rating suggests that a modest cooler from the platform's era would be adequate for stock operation. The 73 W TDP also indicates that the 655K does not require exotic cooling, making it a straightforward drop-in for existing Socket 1156 systems.