Intel Celeron B840

The Intel Celeron B840 is a 2-core, 2-thread mobile processor from the Sandy Bridge generation, built on Intel's 32 nm process. It is a straightforward entry-level part designed for basic computing tasks, and its benchmark data reflects a very specific performance profile that prioritizes efficiency and simplicity over raw capability. The processor carries a 50th percentile ranking against all CPUs in the database, placing it squarely in the middle of the pack historically, though this is a reflection of its era rather than its contemporary standing.

Single-Thread vs Multi-Thread Behavior

The Celeron B840 operates with a base clock of 1900.00 MHz and has no boost clock, meaning it runs at a fixed frequency under all conditions. With only 2 threads, the processor cannot leverage simultaneous multithreading, so its multi-threaded performance is entirely dependent on its physical cores. In workloads that are heavily single-threaded, the fixed 1.9 GHz clock is the limiting factor; there is no headroom for transient speed increases when a single core is under load. This makes the processor predictable but slow by modern standards, as even basic web browsing with numerous tabs can saturate a single thread.

For multi-threaded tasks, the lack of Hyper-Threading is a significant drawback. The 2-thread configuration means that any application designed to use more than two threads will see no benefit beyond the second core. Real-world parallel workloads, such as video encoding or compiling, will effectively stall after the first two threads are occupied. The 2 MB of shared L3 cache is modest and can cause contention when both cores are active, further limiting scaling. The data suggests that this processor is best suited for single-threaded, latency-sensitive tasks like light document editing or legacy software, where the fixed clock can respond without the complexity of boost algorithms.

Power and Thermals

The Celeron B840 has a TDP of 35 watts, which classifies it as a low-power mobile part. This TDP figure is the thermal design point that cooling solutions must handle, and it implies a modest cooling requirement. A basic passive cooler or a small, low-speed fan is sufficient to maintain stable operation, as the 32 nm process and lack of a boost clock keep heat generation constant and manageable. This makes the processor suitable for thin-and-light laptops or compact devices where thermal dissipation is limited.

The 35 W envelope is notably low compared to desktop parts of the same Sandy Bridge generation, which typically had higher TDPs. This efficiency comes at the cost of performance, as the fixed 1.9 GHz clock is well below what the architecture could achieve at higher power limits. For a builder or user, this means that the cooling solution is not a point of concern; any standard mobile cooler will suffice, and the system will run quietly. The trade-off is that the processor will reach its thermal limit long before a cooling solution reaches its own, so there is no headroom for overclocking or sustained high-load operation.

How It Compares

The nearestRivals data for the Celeron B840 is empty, which means there are no direct comparative scores available in the benchmark database. This absence is telling: the processor is so far below contemporary parts that no meaningful rival comparison exists within the dataset. In the context of its own generation, it would sit below the Pentium and Core i3 mobile parts, which had higher clocks and Hyper-Threading. Without specific rival scores, the analysis must rely on the architectural details alone.

Given the 2-core, 2-thread layout and 1.9 GHz fixed clock, the Celeron B840 would be outperformed by any Sandy Bridge Pentium with a higher clock speed and by Core i3 parts that added Hyper-Threading. The 35 W TDP is lower than those parts, which typically had higher power budgets, but this does not translate into a performance advantage. The processor is fundamentally a cost-reduced design, and the empty rival list confirms that it does not compete with anything else in the database on a level playing field.

Who Should Consider It

The Celeron B840 is only relevant for users with legacy software that does not require modern instruction sets or multi-threading. For basic office tasks like word processing, spreadsheet work, and email, the 2 cores are sufficient, provided the user is patient with load times. The fixed 1.9 GHz clock ensures consistent performance without the variability of boost frequencies, which can be an advantage in real-time applications that require predictable latency.

Gaming is not a realistic use case, as the integrated Intel HD (Sandy Bridge) graphics lack the shader units and clock speeds needed for any 3D workload beyond the most basic 2D titles. Creative work such as photo editing or video rendering is similarly out of reach, as those applications are multi-threaded and would max out both cores quickly. The processor is best suited for a secondary machine used for light browsing, document viewing, or as a low-power server for simple scripts. It is not a daily driver for any modern workload.

Benchmark Performance

The benchmark data for the Celeron B840 is empty, with an avgBenchmarkScore of 0 and no entries in the benchmarks array. This means there is no quantitative performance data to analyze against rivals. The 50th percentile ranking is a historical artifact, indicating that at the time of its release, it sat in the middle of all CPUs tracked by the database. However, this ranking is meaningless today, as the database has expanded with far more powerful parts that have pushed the Celeron to the bottom of any modern comparison.

Without exact benchmark scores, the performance assessment must rely on the specifications. A 2-core, 2-thread processor at 1.9 GHz with 2 MB of L3 cache will deliver roughly half the multi-threaded throughput of a 4-thread part at the same clock, and significantly less than any modern processor with higher clocks and more cores. The lack of a boost clock is the most damaging factor, as it caps single-threaded performance at a level that is now considered entry-level even for embedded systems. Any modern Celeron from the last decade would outperform this part by a wide margin, but the absence of rival data prevents a precise percentage delta.

Platform and Compatibility

The Celeron B840 uses the Intel Socket G2 (988B), which is a mobile socket specific to the Sandy Bridge generation. This socket is not compatible with any other processor family, meaning the upgrade path is limited to other Sandy Bridge mobile parts. Since the processor is end-of-life, finding a compatible replacement is a matter of sourcing used parts, and the socket itself is obsolete. The platform supports dual-channel DDR3 memory, which is standard for the era, but there is no memory bandwidth figure provided to assess throughput.

The processor has no PCIe data listed, which is unusual but consistent with its mobile, low-power design; it likely supports PCIe 2.0 lanes for connecting discrete graphics, but this is not confirmed. The integrated graphics are Intel HD (Sandy Bridge), which is a basic GPU capable of video playback and 2D acceleration but not gaming. ECC memory is not supported, ruling out any server or workstation use that requires error correction. The 32 nm process and 504 million transistors on a 131 mm² die are small by modern standards, but the architecture is two generations behind even the later Ivy Bridge parts. For a user considering this platform, the only viable path is a used laptop with the same socket, and even then, the upgrade options are limited to marginally faster Sandy Bridge parts that still lack modern features like AVX2.