Intel Core i5-9400 vs Intel Xeon D-1548 Comparison

The Intel Core i5-9400 and Intel Xeon D-1548 occupy different corners of the Intel lineup, yet their benchmark profiles place them within a striking distance of each other in aggregate performance. The Core i5-9400 is a 6-core, 6-thread desktop part built on Coffee Lake, while the Xeon D-1548 is an 8-core, 16-thread server processor on Broadwell-DE. Despite the Xeon’s older architecture, its additional cores and threads give it a consistent edge across every benchmark recorded in the data. The Core i5-9400 holds a 47th percentile ranking among all CPUs, and the Xeon D-1548 matches that exact percentile, underscoring how close their overall standing is. The average benchmark score for the i5-9400 is 2254, while the Xeon D-1548 sits at 2231, a difference of only about 1%. However, the head-to-head results tell a more one-sided story: the Xeon D-1548 wins all six recorded tests, with deltas ranging from -13.8% to -14.2% in its favor.

Where Each One Wins

The benchmark data is unambiguous: the Intel Xeon D-1548 wins every single recorded benchmark against the Core i5-9400. This includes both multi-core and single-core tests across Cinebench R15, R20, and R23. The largest margin of victory for the Xeon is in Cinebench R20 single-core, where it scores 457 against the i5-9400’s 392, a delta of -14.2%. The smallest margin is also in single-core, in Cinebench R15, where the Xeon’s 109 beats the i5-9400’s 94 by -13.8%. This means the Xeon D-1548 does not just win on parallel workloads where its 16 threads give it a structural advantage; it also wins on lightly threaded tasks, which is a more surprising outcome given the i5-9400’s higher boost clock of 4.10 GHz against the Xeon’s 2.60 GHz.

There is no benchmark category in the FACT PACK where the Core i5-9400 comes out ahead. The i5-9400’s wins column is empty, and the Xeon D-1548’s wins column is six. For use-case planning, this means the Xeon D-1548 is the better choice for any workload captured by these tests, whether that is rendering, general computation, or even single-threaded response. The Core i5-9400 does not have a single metric to point to in this direct comparison. Its only advantage is indirect: it uses the Intel Socket 1151 platform, which is a desktop standard, while the Xeon D-1548 uses Intel BGA 1667, which is soldered and server-oriented. But in terms of raw benchmark scores, the Xeon D-1548 is the clear winner across the board.

Architecture Differences

The two processors come from different architectural generations and are built for different segments. The Core i5-9400 is based on Coffee Lake, specifically the Coffee Lake Refresh generation, and is fabricated on Intel’s 14 nm process. The Xeon D-1548 is based on Broadwell, specifically Broadwell-DE, also on a 14 nm process. Both are manufactured by Intel, but the transistor counts and die sizes differ significantly. The Xeon D-1548 has 3,200 million transistors on a 246 mm² die, while the i5-9400’s transistor count and die size are not listed in the FACT PACK. This suggests the Xeon is a more complex chip, which aligns with its server positioning.

Core and thread counts are a major differentiator. The i5-9400 has 6 cores and 6 threads, meaning no hyper-threading. The Xeon D-1548 has 8 cores and 16 threads, fully hyper-threaded. This gives the Xeon a 2.67x thread advantage in theory, though the benchmark deltas are much smaller, around 14%, because the i5-9400’s clocks are substantially higher. The i5-9400 has a base clock of 2.90 GHz and a boost clock of 4.10 GHz. The Xeon D-1548 has a base clock of 2.00 GHz and a boost clock of 2.60 GHz. That is a 1.5 GHz gap in boost frequency, which explains why the Xeon’s multi-threaded lead is not larger despite having 10 more threads.

Cache layouts also differ. Both have 64 KB of L1 cache per core and 256 KB of L2 cache per core. The L3 cache is where they diverge: the i5-9400 has 9 MB of shared L3 cache, while the Xeon D-1548 has 1.5 MB of L3 per core, which totals 12 MB across 8 cores. The Xeon’s per-core L3 allocation is larger, which may help with server workloads that have high per-thread cache demands. Memory support also differs: the i5-9400 supports DDR4 only, while the Xeon D-1548 supports both DDR3 and DDR4. Both use a dual-channel memory bus, but the i5-9400 lists a memory bandwidth of 42.7 GB/s, while the Xeon D-1548’s bandwidth is not provided. The Xeon D-1548 supports ECC memory, while the i5-9400 does not. PCIe lanes also differ: the i5-9400 has Gen 3 with 16 lanes (CPU only), while the Xeon D-1548 has Gen 3 with 24 lanes (CPU only). The i5-9400 includes integrated graphics (UHD 630), while the Xeon D-1548 has no integrated graphics.

Head-to-Head Benchmarks

The head-to-head results are consistent across all six tests, with the Xeon D-1548 winning every time by roughly the same margin. In Cinebench R15 multi-core, the Xeon scores 777 against the i5-9400’s 668, a delta of -14%. In single-core R15, the Xeon scores 109 against 94, a delta of -13.8%. Moving to Cinebench R20, the multi-core test shows the Xeon at 3239 and the i5-9400 at 2784, again a -14% delta. The single-core R20 test has the Xeon at 457 and the i5-9400 at 392, a -14.2% delta. In Cinebench R23, the multi-core result is 7713 for the Xeon versus 6629 for the i5-9400, a -14.1% delta, and the single-core result is 1089 versus 935, also a -14.1% delta.

The uniformity of these deltas is notable. Across six tests spanning three different Cinebench versions, the Xeon D-1548’s advantage never drops below -13.8% and never exceeds -14.2%. This suggests a consistent performance ceiling for the i5-9400 relative to the Xeon, not a workload-specific advantage. The i5-9400’s higher boost clock of 4.10 GHz does not overcome the Xeon’s core and thread advantage, even in single-core tests. In single-core R23, the Xeon’s 1089 versus the i5-9400’s 935 represents a 16.5% raw score gap, which is larger than the delta percentage might suggest because the delta is calculated relative to the lower score.

The i5-9400 does have a separate Geekbench result, scoring 5141 multi-core and 1389 single-core. The Xeon D-1548 has no Geekbench results in the FACT PACK, so a direct comparison on that test is not possible. However, the Cinebench results alone are sufficient to establish the Xeon’s dominance in this pairing. The i5-9400’s average benchmark score of 2254 is slightly higher than the Xeon’s 2231, but that average includes the Geekbench scores, which are not available for the Xeon. When looking only at the shared Cinebench tests, the Xeon wins everything.

FAQ

Q: Which processor has more cores and threads?

A: The Intel Xeon D-1548 has 8 cores and 16 threads. The Intel Core i5-9400 has 6 cores and 6 threads.

Q: Does the Core i5-9400 win any benchmark against the Xeon D-1548?

A: No. In the head-to-head benchmarks, the Xeon D-1548 wins all six tests, covering Cinebench R15, R20, and R23 in both multi-core and single-core modes.

Q: What is the largest performance gap between the two processors?

A: The largest delta is -14.2%, seen in Cinebench R20 single-core, where the Xeon D-1548 scores 457 and the Core i5-9400 scores 392.

Q: Which processor supports ECC memory?

A: The Intel Xeon D-1548 supports ECC memory. The Intel Core i5-9400 does not support ECC memory.

Q: What are the boost clock speeds of each processor?

A: The Core i5-9400 has a boost clock of 4.10 GHz. The Xeon D-1548 has a boost clock of 2.60 GHz.

Q: Do both processors use the same process node?

A: Yes, both the Core i5-9400 and the Xeon D-1548 are fabricated on Intel’s 14 nm process.

The Verdict

The data points to a single conclusion: the Intel Xeon D-1548 is the superior performer in every recorded benchmark against the Intel Core i5-9400. The Xeon’s 8 cores and 16 threads, combined with its per-core L3 cache of 1.5 MB, deliver consistent wins across all six Cinebench tests, with deltas between -13.8% and -14.2%. The i5-9400’s higher boost clock of 4.10 GHz versus the Xeon’s 2.60 GHz is not enough to overcome the thread deficit, even in single-core tests where the i5-9400 might be expected to shine. The Xeon D-1548 wins single-core R15 by 15 points, single-core R20 by 65 points, and single-core R23 by 154 points.

The Xeon D-1548 is the clear choice for server or workstation workloads that benefit from its 16 threads and ECC memory support. Its 45W TDP (lower than the i5-9400’s 65W TDP) makes it an efficient option for dense deployments, and its 24 PCIe Gen 3 lanes provide more expansion headroom than the i5-9400’s 16 lanes. The i5-9400, on the other hand, offers integrated graphics (UHD 630) and a desktop socket (Intel Socket 1151), making it a more convenient drop-in for consumer builds that do not require a discrete GPU or server-grade reliability. However, in terms of raw compute performance as measured by Cinebench, the Xeon D-1548 is ahead in every category. The i5-9400’s only saving grace is its Geekbench scores, but since the Xeon D-1548 has no Geekbench results in the data, those cannot be used to claim parity. For any user prioritizing multi-threaded performance, ECC support, or PCIe lane count, the Xeon D-1548 is the definitive pick. For a desktop user who needs integrated graphics and a standard socket, the i5-9400 remains a viable but slower alternative. The benchmark evidence is one-sided: six wins for the Xeon D-1548, zero for the Core i5-9400.