Intel Core i3-N305 vs Intel Xeon E3-1245 v5 Comparison

The Intel Core i3-N305 and Intel Xeon E3-1245 v5 are two very different processors that happen to land at nearly the same average benchmark score. The data shows the i3-N305 wins five of six head-to-head tests, but the Xeon takes the single most important win for sustained multi-threaded workloads. This is a classic case where the aggregate score tells you less than the individual test breakdown.

Where Each One Wins

The Intel Core i3-N305 is the clear winner in single-threaded performance and in most older multi-threaded benchmarks. It dominates the Cinebench R15, R20, and R23 single-core tests, and it leads in both Cinebench R15 and R20 multi-core tests. If your workload relies on quick, snappy responses from individual cores, or if you are running software that scales poorly beyond a few threads, the i3-N305 is the stronger choice. Its Geekbench scores of 1049 single-core and 3881 multi-core reinforce this pattern, showing solid all-around performance for a low-power mobile chip.

The Intel Xeon E3-1245 v5 wins only one benchmark, but it is the most demanding one: Cinebench R23 multi-core. This test is a modern stress test that scales well across all available threads. The Xeon's 6822 score versus the i3-N305's 5092 is a 25.4% margin, which is substantial. This indicates that for heavily threaded, long-running workloads like video rendering, 3D modeling, or scientific computing, the Xeon has the endurance and multi-threaded capability to pull ahead. The Xeon also brings server-grade features that the i3-N305 lacks, which we will cover in the architecture section.

Architecture Differences

The two CPUs come from completely different eras and design philosophies. The i3-N305 is a modern, efficient 10 nm part from the Gracemont architecture, part of the Alder Lake-N generation. It has 8 cores and 8 threads, with a base clock of 100.00 MHz and a boost clock of 3.80 GHz. Its cache layout is unusual: 96 KB of L1 per core, 2 MB of L2 per module, and 6 MB of shared L3. It supports DDR4 and DDR5 memory, but only in a single-channel configuration, yielding 38.4 GB/s of bandwidth. It does not support ECC memory. It has 9 PCIe Gen 3 lanes and integrated UHD Graphics 770. Its TDP is just 15 watts, and it is designed for mobile systems.

The Xeon E3-1245 v5 is an older, power-hungry server/workstation chip. It uses the 14 nm Skylake architecture (Skylake-DT) and was released in 2015. It has only 4 cores but 8 threads via Hyper-Threading. Its base clock is 3.50 GHz and boost is 3.90 GHz. The cache is more traditional: 64 KB L1 per core, 256 KB L2 per core, and 8 MB of shared L3. It supports DDR3 and DDR4 in a dual-channel configuration, providing 34.1 GB/s of bandwidth. Crucially, it supports ECC memory, which is a major feature for stability in server environments. It has 16 PCIe Gen 3 lanes and integrated HD Graphics P530. Its TDP is 80 watts, more than five times that of the i3-N305. The Xeon is also end-of-life and uses the Intel Socket 1151, while the i3-N305 uses the BGA 1264 socket and is still active in production.

Head-to-Head Benchmarks

The benchmark results paint a split picture. In Cinebench R15 multi-core, the i3-N305 scores 829 versus the Xeon's 687, a 20.7% lead. The single-core R15 test is even more lopsided: 164.7 versus 96, a 71.6% difference. That is a massive gap, showing the i3-N305's Gracemont cores have far superior per-thread performance in this older test.

Moving to Cinebench R20, the i3-N305 continues its multi-core lead with 3349 versus 2865, a 16.9% advantage. The single-core R20 test shows a 16.8% lead for the i3-N305 as well, with scores of 472 versus 404. At this point, the i3-N305 has won four consecutive tests.

The tide turns in Cinebench R23. The Xeon E3-1245 v5 scores 6822 in multi-core, while the i3-N305 manages only 5092. This is a 25.4% win for the Xeon, and it is not a small margin. The i3-N305 does take the R23 single-core test with 995 versus 963, but that is only a 3.3% lead, which is nearly negligible. The data suggests that the Xeon's 8 threads, while fewer in core count, are better optimized for the sustained, heavy load of the R23 multi-core test. The i3-N305's efficiency cores seem to hit a thermal or power ceiling under this sustained load, allowing the Xeon's higher TDP and dual-channel memory to shine.

Specification Differences

The specifications where these two CPUs differ are stark:

• Cores: 8 (i3-N305) vs 4 (Xeon E3-1245 v5)
• Threads: 8 vs 8
• Base Clock: 100.00 MHz vs 3.50 GHz
• Boost Clock: 3.80 GHz vs 3.90 GHz
• TDP: 15 W vs 80 W
• Socket: Intel BGA 1264 vs Intel Socket 1151
• Architecture: Gracemont vs Skylake
• Process Node: 10 nm vs 14 nm
• Transistors: Not listed vs 1,750 million
• Die Size: Not listed vs 122 mm²
• L1 Cache: 96 KB (per core) vs 64 KB (per core)
• L2 Cache: 2 MB (per module) vs 256 KB (per core)
• L3 Cache: 6 MB (shared) vs 8 MB (shared)
• Memory Support: DDR4, DDR5 vs DDR3, DDR4
• Memory Bus: Single-channel vs Dual-channel
• Memory Bandwidth: 38.4 GB/s vs 34.1 GB/s
• ECC Memory: No vs Yes
• PCIe: Gen 3, 9 Lanes vs Gen 3, 16 Lanes
• Integrated Graphics: UHD Graphics 770 vs HD Graphics P530
• Market Segment: Mobile vs Server/Workstation
• Production Status: Active vs End-of-life
• Release Date: 2023-01-02 vs 2015-10-18
• Launch MSRP: $309 vs $294

Note that despite the i3-N305 having a higher memory bandwidth figure, the Xeon's dual-channel setup is often more effective in practice for multi-threaded workloads, which the R23 result seems to confirm.

FAQ

Q: Which CPU is faster in single-core performance?

A: The Intel Core i3-N305 is significantly faster. It wins the Cinebench R15 single-core test by 71.6% (164.7 vs 96) and the R20 single-core test by 16.8% (472 vs 404). In R23 single-core, it leads by 3.3% (995 vs 963).

Q: Why does the Xeon E3-1245 v5 win the Cinebench R23 multi-core test if it has fewer cores?

A: The Xeon has 8 threads and a dual-channel memory bus, plus a much higher 80 W TDP. The data shows it scored 6822 versus the i3-N305's 5092, a 25.4% advantage. This suggests the Xeon is better able to sustain heavy multi-threaded loads without throttling.

Q: Does the i3-N305 support ECC memory?

A: No. The i3-N305 does not support ECC memory. The Xeon E3-1245 v5 does support ECC memory, which is a key feature for server and workstation stability.

Q: Which processor is more power-efficient?

A: The i3-N305 has a TDP of 15 watts, while the Xeon E3-1245 v5 has a TDP of 80 watts. The i3-N305 is designed for mobile and low-power systems.

Q: What is the difference in memory bandwidth?

A: The i3-N305 has a rated memory bandwidth of 38.4 GB/s, but it uses a single-channel bus. The Xeon has a lower rated bandwidth of 34.1 GB/s, but it uses a dual-channel bus, which can be more efficient for multi-threaded data access.

Q: Are both processors still in production?

A: No. The i3-N305 is listed as Active in production. The Xeon E3-1245 v5 is listed as End-of-life.

The Verdict

The data is clear: the Intel Core i3-N305 is the better all-around processor for most users. It wins 5 out of 6 head-to-head benchmarks, including all single-core tests and the R15 and R20 multi-core tests. It does this with a fraction of the power draw (15 W vs 80 W) and is a current, active product. Its performance in Geekbench (3881 multi-core, 1049 single-core) confirms it is a capable chip for everyday tasks and lightly threaded applications.

The Intel Xeon E3-1245 v5 is the pick only if your primary workload is sustained, heavily multi-threaded rendering or computation, as evidenced by its 25.4% lead in Cinebench R23 multi-core. It also brings ECC memory support and 16 PCIe lanes, which are essential for certain server and workstation environments. However, it is an end-of-life product with a much higher TDP, and it loses decisively in single-core performance and in most other multi-core tests.

Choose the i3-N305 for a modern, efficient system with strong single-thread performance and good multi-threaded scores. Choose the Xeon E3-1245 v5 only if you specifically need ECC memory support and you have workloads that mirror the Cinebench R23 multi-core test's demands, where its dual-channel memory and higher power envelope give it a clear edge.