Intel Core i7-640UM

Platform and Compatibility

The Intel Core i7-640UM is a mobile processor built on the Westmere architecture, specifically the Arrandale codename, and it belongs to the first generation of Core i7 processors. It uses the Intel BGA 1288 socket, which is a soldered, non-upgradeable platform typical of ultra-low-voltage mobile designs from that era. The chip is produced on Intel's 32 nm process node, with 382 million transistors packed into an 81 mm² die. This is a dual-core part with Hyper-Threading, providing four threads, and it features a 4 MB shared L3 cache, alongside 64 KB of L1 cache per core and 256 KB of L2 cache per core.

Memory support is limited to DDR3, operating on a dual-channel bus with a theoretical bandwidth of 17.1 GB/s. There is no ECC memory support, which aligns with its consumer mobile positioning. The integrated graphics solution is HD Graphics (Ironlake), which is the GPU block integrated into the Arrandale die. PCIe support is Gen 2, which was current for its release period. The processor is marked as end-of-life in production status, having been released on January 6, 2010, with a launch MSRP of $305. The multiplier is locked, so overclocking is not an option. The part number is SLBMMSLBSRQ4B5.

For upgrade path considerations, the BGA 1288 socket means the processor is permanently attached to the motherboard. There is no socket-based upgrade possible; the entire platform would need replacement for any performance improvement. The platform's memory controller is dual-channel DDR3, and the 17.1 GB/s bandwidth is a hard ceiling for data throughput. The PCIe Gen 2 support limits expansion options relative to later standards, though for a low-power mobile chip of this vintage, that is not a primary concern. The integrated graphics mean no discrete GPU is strictly required for basic display output, but the Ironlake solution is extremely modest by modern standards.

Power and Thermals

The TDP of this processor is 18 watts, which places it firmly in the ultra-low-voltage (ULV) mobile segment. This is a very low power envelope, designed for thin-and-light laptops where battery life and thermal management take priority over raw performance. The 1200 MHz base clock and 2.27 GHz boost clock are both quite low, which is a direct consequence of the power budget. A TDP of 18 watts implies that a passive or very small active cooling solution is sufficient. The data shows no need for a substantial heat sink or high-RPM fan; a slim heat pipe and a small blower fan are typical for this class.

Thermal management is further aided by the 32 nm process node, which reduces leakage current compared to older 45 nm parts. The boost clock of 2.27 GHz is a significant jump from the base 1200 MHz, but it is likely sustainable only for short bursts or when a single core is active, due to the shared thermal budget. In sustained multi-core workloads, the processor will likely settle closer to the base clock to stay within the 18-watt envelope. This is not a chip for sustained heavy compute; it is engineered for intermittent tasks and low idle power. The integrated HD Graphics (Ironlake) shares the same thermal package, so any GPU load also competes for the same 18-watt budget, further limiting CPU boost behavior under combined loads.

Single-Thread vs Multi-Thread Behavior

The benchmark data reveals a stark contrast between single-thread and multi-thread performance. In Cinebench R23, the single-core score is 140, while the multi-core score is 992. This represents a multi-core scaling factor of roughly 7.1x, which is far above the theoretical 2x from two physical cores and even the 4x from four threads. This unusual scaling indicates that the single-core score is heavily constrained, likely by the low base clock and thermal limits, while the multi-core test can utilize both cores at slightly higher sustained clocks or with better scheduling.

In Cinebench R20, the single-core score is 58 and the multi-core score is 416, a scaling factor of 7.2x, which is consistent with the R23 results. The Cinebench R15 multi-core score is 99, which is very low in absolute terms. The single-core scores are so low that they are below the threshold of what modern desktop processors produce in their sleep state. The practical interpretation is that this chip will feel sluggish in any single-threaded application, such as older games, web browsers with heavy JavaScript, or spreadsheet recalculation. Multi-threaded workloads that can use four threads will show relatively better performance, but the absolute scores are still far below any contemporary processor.

For real workloads, this split means that the i7-640UM is better suited to parallel tasks like batch photo editing or video encoding where all four threads can be engaged, rather than latency-sensitive single-thread tasks. However, the multi-core scores are so low (Cinebench R23 multi-core of 992) that even parallel workloads will be slow compared to any modern chip. The boost clock of 2.27 GHz is available for single-core bursts, but the single-core benchmark scores indicate that it is not being sustained effectively, possibly due to the integrated GPU or other platform limits.

How It Compares

Intel Celeron G540: The Celeron G540 has an average benchmark score of 342, which is essentially identical to the i7-640UM's 341 average. The delta is -0.2%, meaning the Celeron is marginally behind. This is a surprising result because the G540 is a desktop part with a higher TDP, but its lack of Hyper-Threading and older architecture bring it down to the same level as the ultra-low-voltage mobile chip. The i7-640UM matches a desktop Celeron from the same era, which underscores how much the 18-watt TDP limits performance.

Intel Xeon W3505: The Xeon W3505 scores 340, with a delta of +0.4% relative to the i7-640UM. This is another near-tie. The Xeon is a dual-core server part without Hyper-Threading, and it runs at a higher clock speed, but the i7-640UM's four threads close the gap. The data shows that the mobile ULV chip trades blows with a workstation-class Xeon from the same generation, which is a testament to the efficiency of the Westmere architecture at low power, but also a sign that neither chip is competitive by modern standards.

Intel Celeron 1000M: The Celeron 1000M has an average score of 339, with a delta of +0.5% for the i7-640UM. This Celeron is a newer Ivy Bridge part, but it has only two cores and no Hyper-Threading. The i7-640UM's four threads give it a slight edge, but the margin is within noise. This comparison highlights that even a newer dual-core Celeron without SMT is roughly equivalent in overall performance, meaning the i7-640UM's value comes primarily from its power efficiency, not its compute capability.

AMD A4-4300M: The AMD A4-4300M scores 339, with a delta of +0.6% for the i7-640UM. This is a dual-core AMD APU with integrated graphics, and it is also a mobile part. The margin is tiny, and both chips are in the same performance class. The A4-4300M likely has a higher TDP, so the i7-640UM is more power-efficient per unit of performance, but in raw throughput, they are indistinguishable. This comparison shows that the i7-640UM is representative of the lowest tier of mobile computing from its era.

Who Should Consider It

Based on the benchmark data, this processor is not suitable for any modern gaming workload. The Cinebench R23 single-core score of 140 is far below the threshold needed for even basic 3D games, and the integrated HD Graphics (Ironlake) is not capable of running any contemporary game at playable frame rates. The multi-core score of 992 in R23 is similarly inadequate for game physics or AI calculations. This chip is strictly for legacy office productivity where the primary tasks are word processing, spreadsheet entry, and email.

For content creation, the results are equally discouraging. The Cinebench R20 multi-core score of 416 and R15 multi-core score of 99 indicate that video rendering or large batch photo operations would take an impractically long time. The only realistic use case is for a secondary machine used for light document editing or as a basic web browsing terminal, provided the user is patient with slow page loads and simple JavaScript. The four threads do provide some benefit in multitasking multiple office applications, but the low single-core scores mean that each individual application will feel unresponsive.

The target user is someone who needs a battery-efficient laptop for travel or field work where the primary tasks are writing, reading, and light communication. The 18-watt TDP allows for long battery life, and the low heat output means a fanless or near-silent design is possible. However, the performance is so low that it is only recommended for users who have no alternative and prioritize battery life over every other metric. The average benchmark score of 341 places this chip in the 2nd percentile of all CPUs, meaning it is slower than 98% of all processors ever benchmarked.

FAQ

Q: Does the Intel Core i7-640UM support ECC memory?

A: No, ECC memory is not supported. The memory support is DDR3 on a dual-channel bus, with a maximum bandwidth of 17.1 GB/s.

Q: What is the socket type for this processor?

A: The socket is Intel BGA 1288, which is a soldered mobile socket. The processor cannot be removed or upgraded without replacing the entire motherboard.

Q: How many threads does the i7-640UM have?

A: It has 2 physical cores and 4 threads due to Hyper-Threading. The base clock is 1200 MHz and the boost clock is 2.27 GHz.

Q: What is the production status of this chip?

A: The production status is end-of-life. It was released on January 6, 2010, and is no longer manufactured.

Q: How does the i7-640UM perform in Cinebench R23?

A: The multi-core score is 992 and the single-core score is 140. These are very low scores, placing the chip in the 2nd percentile of all CPUs.

Q: Is the multiplier unlocked for overclocking?

A: No, the multiplier is locked. The processor does not support overclocking, and the 18-watt TDP leaves no headroom for manual tuning.

Benchmark Performance

The average benchmark score for the Intel Core i7-640UM is 341, which places it in the 2nd percentile of all CPUs. This is an extremely low ranking, indicating that almost every other processor ever tested outperforms it. The nearest rivals all have average scores within a single point of 341, making this a tightly clustered performance tier at the very bottom of the CPU hierarchy.

In Cinebench R23, the multi-core score of 992 is the highest multi-threaded result for this chip, while the single-core score of 140 is the lowest single-threaded result. The ratio between them is 7.09x, which is exceptionally high. This suggests that the single-core performance is disproportionately penalized by the low base clock and thermal constraints, while the multi-core test benefits from the four threads. In Cinebench R20, the multi-core score is 416 and the single-core score is 58, a ratio of 7.17x. The Cinebench R15 multi-core score is 99, which is the lowest absolute score in the benchmark suite.

Comparing to the nearest rivals, the deltaPct values are all within ±0.6%. The Intel Celeron G540 has a delta of -0.2%, meaning the i7-640UM is actually slightly faster on average. The Intel Xeon W3505 has a delta of +0.4%, meaning the i7-640UM is slightly slower. The Intel Celeron 1000M has a delta of +0.5%, and the AMD A4-4300M has a delta of +0.6%. These margins are negligible and well within run-to-run variance. The data shows that the i7-640UM is functionally equivalent to all four rivals, despite the very different architectures and power envelopes.

The benchmark results paint a clear picture: this is a processor for ultra-portable devices where power consumption is the primary design goal. The 18-watt TDP and 2nd percentile ranking mean that it is not competitive with any modern processor, and even its contemporaries at the same price point offer similar or better performance. The only scenario where this chip makes sense is in a legacy laptop that is still functional and requires no upgrades. The scores are consistent across all benchmarks, showing no hidden strengths; it is uniformly slow in both single-threaded and multi-threaded workloads. The 341 average score is the definitive metric, and it places this chip at the very bottom of the performance spectrum.