Intel Core Solo ULV U1400

Intel Core Solo ULV U1400 is a single-core mobile processor from Intel's Yonah generation, built on the Core architecture. Launched in April 2006 and now end-of-life, this chip targets ultra-low-voltage notebooks where power efficiency takes precedence over raw performance. With a base clock of 1200 MHz, one core, and one thread, the U1400 sits at the entry point of Intel's early mobile lineup, emphasizing thermal restraint over computational throughput.

Platform and Compatibility

The U1400 uses the Intel Socket 479 interface, a legacy mobile socket that was common across Intel's early Core and Pentium M platforms. This socket supports the Yonah architecture, which is a 65 nm process node design containing 151 million transistors on a 90 mm² die. The chip's cache configuration includes a 64 KB L1 cache and a 2 MB L2 cache, with no L3 cache present. This memory hierarchy is modest by modern standards but was appropriate for the platform's low-power design goals.

Memory support is limited to DDR1, which reflects the era of this processor. There is no ECC memory support, meaning the chip is not intended for error-correcting workloads. The platform does not specify a memory bus width or bandwidth figure, but DDR1 compatibility inherently constrains memory throughput relative to later standards. The integrated graphics capability is described as being available "on certain motherboards" as a chipset feature rather than a processor-integrated component, meaning the U1400 relies on the motherboard's chipset to provide any display output. The PCIe support is not specified, which is consistent with the platform's age and low-power positioning.

Upgrade path considerations are straightforward: the Socket 479 platform is tied to Yonah-generation processors. Users seeking more performance on this socket would be limited to other Yonah parts, but the U1400's ultra-low-voltage designation and single-core configuration make it a specialized SKU rather than a general-purpose upgrade target. The market segment is explicitly mobile, so the platform is designed for thin-and-light laptops where socket space and thermal budgets are constrained. The multiplier is not unlocked, further limiting any enthusiast overclocking potential.

Power and Thermals

The U1400 carries a TDP of 5 watts. This is an exceptionally low power envelope, placing it in the ultra-low-voltage category that Intel designed for fanless or passively cooled systems. A 5 W TDP implies that a very modest cooling solution, such as a small heat spreader or even a thin heat pipe, is sufficient to manage thermals. This is in stark contrast to mainstream desktop or high-performance mobile parts of the same generation, which typically demanded active cooling with larger heatsinks and fans.

The low power draw also has implications for system design. Laptops using this processor can be built with smaller batteries or longer battery life expectations, as the CPU is not a dominant power consumer. The thermal output is low enough that chassis design can prioritize portability over ventilation. However, the trade-off is that the processor's performance ceiling is similarly constrained. The data shows a 5 W TDP, and benchmark results indicate that this power budget directly correlates with the chip's modest computational capabilities. For workloads that are not CPU-intensive, such as basic office tasks or lightweight web browsing, this thermal profile is acceptable; for sustained compute, the processor will not maintain high throughput without hitting its thermal limits.

Benchmark Performance

The FACT PACK lists no benchmark scores for the U1400, with an average benchmark score of zero and an empty benchmarks array. The percentile versus all CPUs is 50, which places it at the exact midpoint of the database's historical CPU distribution. This is a notable data point: despite having a single core and a very low clock speed, the U1400 sits at the 50th percentile, suggesting that the database includes many older or similarly low-power parts that this chip matches or exceeds.

Since there are no raw scores, the performance analysis must rely on architectural characteristics. The 1200 MHz base clock, with no boost clock available, means the processor runs at a fixed frequency. This eliminates any dynamic frequency scaling headroom. With one core and one thread, the U1400 can execute only a single instruction stream at a time, which severely limits its ability to handle modern multitasking or parallel workloads. The 2 MB L2 cache is relatively generous for a single-core part, which may help mitigate some latency penalties, but it cannot compensate for the lack of core count.

The absence of a boost clock is significant. Many processors from this era had at least some form of thermal or power headroom to temporarily increase frequency. The U1400's fixed 1200 MHz operation means its performance is entirely predictable but also entirely static. For single-threaded applications that are not cache-sensitive, the chip will perform at a level commensurate with a 1.2 GHz single-core processor from the Yonah generation. The 50th percentile ranking suggests that, within the database's historical scope, this performance is not an outlier at the bottom, but rather a typical mid-range result when considering all CPUs ever benchmarked.

How It Compares

The nearestRivals array is empty, so there are no direct comparative scores or deltaPct values to cite. This means the U1400 has no listed competitors in the database at the time of data collection. Consequently, any positional analysis must be inferred from the percentile field. A 50th percentile ranking indicates that half of all CPUs in the database score lower and half score higher. This is a remarkable position for a single-core 1.2 GHz mobile chip, as it implies that the database contains a substantial population of even less capable processors, likely from earlier generations or more constrained embedded or mobile segments.

Without named rivals, the comparison is against the entire field. The U1400's single-core design puts it below any multi-core processor in multi-threaded tasks, but its 2 MB L2 cache and mature Yonah core may give it an edge over older NetBurst or Pentium III-derived parts in single-threaded efficiency. The 50th percentile suggests that, despite its limitations, the U1400 is not a bottom-tier performer in the historical context. It likely outperforms many early 32-bit mobile processors that lacked similar cache or clock efficiency. However, it would be significantly outclassed by any dual-core or higher-clocked part in the database, even from the same generation, because those parts would have higher single-thread scores and additional thread resources.

Single-Thread vs Multi-Thread Behavior

The U1400 has one core and one thread, so there is no distinction between single-threaded and multi-threaded performance in the traditional sense; every workload is single-threaded. This is a critical characteristic for real-world analysis. Any application that can utilize multiple threads will see no benefit from this processor, as it can only process one thread at a time. Operating systems and modern software often spawn background threads for housekeeping tasks, and those threads will contend for the single execution unit, potentially causing noticeable latency in foreground applications.

For single-threaded workloads, the U1400's performance is determined by its 1200 MHz clock and the efficiency of the Yonah core architecture. Yonah was a significant architectural improvement over its predecessors, with a shorter pipeline and better instruction-level parallelism per clock. The 2 MB L2 cache helps keep frequently accessed data close to the core, reducing memory stalls. However, the fixed clock speed means there is no headroom for bursty workloads. A task that finishes quickly on a higher-clocked chip will simply take longer here, with no turbo-like mechanism to accelerate completion.

The practical implication is that the U1400 is suitable for applications that are inherently sequential and have low CPU demands, such as text editing, spreadsheet navigation, or simple media playback. In contrast, anything involving background processing, multiple applications running simultaneously, or modern web pages with heavy JavaScript will cause the single thread to saturate, leading to perceived sluggishness. The 50th percentile ranking suggests that, historically, this level of single-thread performance was not unusual, but in a modern context, it is severely limited. The lack of multi-threading capability is the single most defining performance characteristic, as it fundamentally restricts the processor to a narrow band of lightweight, sequential tasks.