Intel Xeon L5420

The Intel Xeon L5420 is a 45 nm Harpertown-generation Xeon built by Intel for the Server/Workstation market segment. It uses the Core 2 architecture, has 4 cores and 4 threads, and runs at a base clock of 2.50 GHz with no boost clock listed. Released on 2008-03-24 and now end-of-life, it has an average benchmark score of 626 and sits at the 15th percentile of all CPUs in the database.

Platform and Compatibility

The L5420 is built for Intel Socket 771, and that socket is the physical compatibility boundary for motherboards. The architecture is Intel's Core 2, with the codename Harpertown; the generation field in the data is "Xeon (Harpertown)". Intel is the foundry, and the process node is 45 nm. The die size is 2x 107 mm², and the transistor count is 820 million. On the cache side, the L5420 has 64 KB of L1 cache per core and 6 MB of L2 cache per die; L3 cache is not listed. The memory interface is dual-channel, with DDR2 and DDR3 support depending on the motherboard, and ECC memory is supported. PCIe connectivity is Gen 2. The part number is SLARPSLBBR, and the launch MSRP is $380.

Because this is a Server/Workstation part with a production status of end-of-life, the upgrade path is tied to Socket 771 motherboards that support the Harpertown generation. The motherboard dependency for DDR2 versus DDR3 also shapes memory choices. The L5420 does not list integrated graphics, so any display output would depend on a separate component. The platform data stops at PCIe Gen 2 and does not include a newer interface, which means the expansion capabilities of any system using this processor are defined by that Gen 2 interface.

Power and Thermals

The TDP of the L5420 is 50W. For a quad-core server/workstation processor, 50W is a low thermal envelope. The 45 nm process and 820 million transistor count provide the physical context for that 50W figure. The multiplier is locked, and no boost clock is listed, so the 2.50 GHz base clock is the only frequency in the data. A 50W TDP implies that cooling solutions need to handle modest heat output from the four cores, but the data does not include a specific cooler size requirement. The locked multiplier also means there is no unlocked frequency adjustment path in the data; frequency control is anchored to the base 2.50 GHz operation. For dense server or workstation designs, that fixed low-power profile is a notable characteristic.

Single-Thread vs Multi-Thread Behavior

The L5420 provides 4 cores and 4 threads. Because those two numbers are equal, the processor does not list extra threads beyond one per core. The base clock is 2.50 GHz, and there is no boost clock, so the listed frequency is the same for all workloads. In Cinebench R20, the single-core score is 107 and the multi-core score is 764. In Cinebench R23, the single-core score is 257 and the multi-core score is 1821. The Cinebench R15 result is a multi-core score of 183.

The single-core and multi-core numbers diverge clearly. This indicates that workloads able to use all four cores extract substantially more performance than workloads limited to one thread. Single-threaded performance remains tied to the 2.50 GHz base clock, while multi-threaded performance comes from all four physical cores. The absence of a boost clock means there is no listed mechanism to raise frequency above 2.50 GHz, so lightly threaded workloads do not get a frequency lift. The data therefore points to a CPU that behaves better in threaded server or workstation tasks than in latency-sensitive single-thread tasks.

How It Compares

The nearest rival data lists four processors, each with average scores close to the L5420's 626.

Against the Intel Core i5-2450M, the L5420's average score is 626 versus 625. The deltaPct is 0.2%, so the L5420 is ahead by that small margin.

Against the Intel Celeron N4505, the average scores are 626 and 624. The deltaPct is 0.3%.

Against the Intel Celeron G3900, the same 626-to-624 comparison appears, with a deltaPct of 0.3%.

Against the Intel Celeron 4305U, the L5420 is again 0.3% ahead, with 626 versus 624.

All four nearest rivals are below the L5420 in average score. The Core i5-2450M is the closest competitor at 0.2%, while the three Celerons are grouped together at 0.3%. The deltas are small enough that the L5420 and these rivals occupy effectively the same performance tier.

Benchmark Performance

The average benchmark score of the L5420 is 626. At the 15th percentile of all CPUs, this processor sits below the majority of entries in the database. Its four nearest rivals are tightly grouped: the Core i5-2450M averages 625, and the Celeron N4505, Celeron G3900, and Celeron 4305U each average 624. The deltaPct values are 0.2% for the Core i5-2450M and 0.3% for all three Celeron parts. Thus the L5420 is at the top of this immediate cluster, but only by a narrow margin.

In Cinebench R15 multi-core, the L5420 scores 183. In Cinebench R20, the multi-core score is 764 and the single-core score is 107. In Cinebench R23, the multi-core score is 1821 and the single-core score is 257. These results show a processor with much higher multi-core throughput than single-core throughput on the same benchmark versions. In R20, the multi-core score is far above the single-core score; in R23, the same pattern holds. The fixed 2.50 GHz base clock and the absence of a boost clock keep single-core results in check, while the four cores collectively produce the large multi-core numbers. Because all nearest rivals are within 0.3%, the benchmark data does not place the L5420 in a meaningfully different performance class from those CPUs.

FAQ

Q: What socket and architecture does the L5420 use?

A: It uses Intel Socket 771, with Intel's Core 2 architecture and the codename Harpertown.

Q: What memory support is available?

A: DDR2 and DDR3, depending on motherboard, over a dual-channel memory bus, with ECC support.

Q: Does it have integrated graphics?

A: No integrated graphics are listed.

Q: Is the multiplier unlocked?

A: No, the multiplier is locked; the base clock is 2.50 GHz and no boost clock is listed.

Q: What are the core and thread counts?

A: It has 4 cores and 4 threads.

Q: What is its average benchmark score?

A: Its average benchmark score is 626, placing it at the 15th percentile of all CPUs in the database.