Intel Core i5-9400T vs Intel Xeon E5-4648 v3 Comparison

The Verdict

The benchmark data is unambiguous: the Intel Xeon E5-4648 v3 wins all six head-to-head comparisons against the Intel Core i5-9400T. Its victory margins are remarkably consistent, ranging from 11.7% to 12.4% across both multi-core and single-core Cinebench tests. The Xeon leads by 11.7% in Cinebench R15 multi-core (776 vs 695), by 12.4% in R15 single-core (109 vs 97), by 11.7% in R20 multi-core (3234 vs 2896), by 11.8% in R20 single-core (456 vs 408), by 11.7% in R23 multi-core (7701 vs 6896), and by 11.7% in R23 single-core (1087 vs 973). There is no workload category in the recorded data where the Core i5-9400T pulls ahead.

The Xeon E5-4648 v3 is the clear pick for any workload that stresses sustained throughput across many threads. It offers 12 cores and 24 threads versus the Core i5-9400T's 6 cores and 6 threads, which explains why its multi-core advantage is substantial in every Cinebench iteration. The Core i5-9400T, despite having a higher boost clock (3.40 GHz vs 2.20 GHz) and a newer architecture (Coffee Lake vs Haswell), cannot overcome the Xeon's doubling of cores and quadrupling of threads. The data indicates that the Xeon is the better choice for rendering, compilation, or any parallel compute task.

The Core i5-9400T, however, should not be dismissed entirely. Its lower 35 W TDP versus the Xeon's 105 W TDP makes it a far less demanding part for system builders, and it includes integrated UHD 630 graphics, a feature the Xeon lacks entirely. The Core i5 also supports a smaller platform footprint with a dual-channel memory bus and 16 PCIe lanes, suiting a desktop build where the Xeon's quad-channel memory and 40 PCIe lanes are unnecessary. For users who need a compact, low-power desktop processor with built-in display output, the Core i5-9400T is the only sensible option from these two, but the performance crown belongs to the Xeon.

The overall average benchmark scores reinforce this split. The Xeon E5-4648 v3 posts an average score of 2227, while the Core i5-9400T sits at 2136. Both processors land at the 47th percentile of all CPUs in the database, meaning they occupy similar positions in the overall performance distribution, but the Xeon does so with a higher raw score and an older, server-oriented design.

Architecture Differences

The Intel Xeon E5-4648 v3 is built on the Haswell-EP architecture using a 22 nm process node, while the Intel Core i5-9400T uses the Coffee Lake architecture on a 14 nm node. The Xeon is manufactured on a larger process, yet it packs 2,600 million transistors into a 356 mm² die. The Core i5-9400T has no listed transistor count or die size in the database, so a direct comparison of those physical characteristics is not possible.

The Xeon's core configuration is fundamentally different: 12 physical cores with Hyper-Threading, yielding 24 threads. The Core i5-9400T offers 6 physical cores and 6 threads, with no Hyper-Threading support. This thread-count disparity is the single largest architectural factor separating the two parts. The Xeon also carries a significantly larger shared L3 cache at 30 MB versus the Core i5's 9 MB. L1 and L2 caches are identical on a per-core basis: 64 KB and 256 KB respectively.

Memory architecture diverges sharply. The Xeon supports quad-channel DDR4 with a peak memory bandwidth of 59.7 GB/s, and it supports ECC memory. The Core i5-9400T uses dual-channel DDR4 with a peak bandwidth of 42.7 GB/s and has no ECC support. For memory-intensive server or workstation workloads, the Xeon's wider memory bus and ECC capability are significant advantages.

The two processors also differ in platform connectivity. The Xeon provides 40 PCIe Gen 3 lanes (CPU only), while the Core i5 provides 16 PCIe Gen 3 lanes. The Xeon uses the Intel Socket 2011-3, a large server platform, while the Core i5 uses the Intel Socket 1151, a mainstream desktop socket. The Xeon has no integrated graphics; the Core i5 includes Intel UHD 630 graphics. The Xeon was released in May 2015, while the Core i5 arrived in August 2018, but both are now marked as end-of-life production status.

Neither processor has an unlocked multiplier, so overclocking potential is limited for both parts. The Xeon carries a launch MSRP of $2405, reflecting its server-class positioning, while the Core i5 has no launch MSRP in the database.

Head-to-Head Benchmarks

The Xeon E5-4648 v3 wins every recorded comparison. In Cinebench R15 multi-core, the Xeon scores 776 against the Core i5's 695, a 11.7% advantage. The single-core R15 result is the largest margin in the entire dataset: the Xeon scores 109 versus 97, a 12.4% lead. This is notable because the Core i5 has a much higher boost clock of 3.40 GHz compared to the Xeon's 2.20 GHz, yet the older Haswell design still manages a higher single-core score. The database indicates that the Xeon's per-thread efficiency in this test exceeds what the higher-clocked Coffee Lake part can deliver.

Cinebench R20 multi-core shows the Xeon at 3234 versus 2896, another 11.7% margin. The single-core R20 test has the Xeon at 456 versus 408, an 11.8% lead. These results mirror the R15 pattern almost exactly, suggesting that the performance relationship between these two CPUs is stable across different Cinebench versions and workload intensities.

Cinebench R23 multi-core continues the trend: the Xeon scores 7701, the Core i5 scores 6896, a 11.7% difference. The R23 single-core test has the Xeon at 1087 versus 973, again an 11.7% margin. The consistency across all six tests is striking. The deltas cluster tightly between 11.7% and 12.4%, indicating that the Xeon's advantage is not workload-specific but rather a general property of its architecture and core configuration.

The Core i5-9400T does have additional Geekbench results in the database (multi-core 3969, single-core 1152), but the Xeon E5-4648 v3 has no corresponding Geekbench scores, so a head-to-head comparison in that test is not possible from the recorded data.

Specification Differences

The key specification differences between the two processors are as follows:

• Cores: Xeon E5-4648 v3 has 12 cores; Core i5-9400T has 6 cores.
• Threads: Xeon E5-4648 v3 has 24 threads; Core i5-9400T has 6 threads.
• Base clock: Xeon E5-4648 v3 runs at 1700.00 MHz; Core i5-9400T runs at 1800.00 MHz.
• Boost clock: Xeon E5-4648 v3 boosts to 2.20 GHz; Core i5-9400T boosts to 3.40 GHz.
• TDP: Xeon E5-4648 v3 is rated at 105 W; Core i5-9400T is rated at 35 W.
• Socket: Xeon E5-4648 v3 uses Intel Socket 2011-3; Core i5-9400T uses Intel Socket 1151.
• Architecture: Xeon E5-4648 v3 is Haswell (Haswell-EP); Core i5-9400T is Coffee Lake.
• Process node: Xeon E5-4648 v3 is 22 nm; Core i5-9400T is 14 nm.
• Transistors: Xeon E5-4648 v3 has 2,600 million; Core i5-9400T has none listed.
• Die size: Xeon E5-4648 v3 is 356 mm²; Core i5-9400T has none listed.
• L3 cache: Xeon E5-4648 v3 has 30 MB shared; Core i5-9400T has 9 MB shared.
• Memory bus: Xeon E5-4648 v3 is quad-channel; Core i5-9400T is dual-channel.
• Memory bandwidth: Xeon E5-4648 v3 is 59.7 GB/s; Core i5-9400T is 42.7 GB/s.
• ECC memory: Supported on Xeon E5-4648 v3; not supported on Core i5-9400T.
• PCIe lanes: Xeon E5-4648 v3 has 40 Gen 3 lanes (CPU only); Core i5-9400T has 16 Gen 3 lanes.
• Integrated graphics: Xeon E5-4648 v3 has none; Core i5-9400T has UHD 630.
• Market segment: Xeon E5-4648 v3 is Server/Workstation; Core i5-9400T is Desktop.
• Release date: Xeon E5-4648 v3 released 2015-05-31; Core i5-9400T released 2018-08-31.
• Launch MSRP: Xeon E5-4648 v3 is $2405; Core i5-9400T has none listed.
• Part number: Xeon E5-4648 v3 is SR26R; Core i5-9400T is SR3X8.

Both processors share the same L1 and L2 cache sizes per core, both support DDR4 memory, both are manufactured by Intel, both have locked multipliers, and both are end-of-life products.

FAQ

Q: Which processor wins in multi-core performance?

A: The Intel Xeon E5-4648 v3 wins all three multi-core Cinebench tests. It leads by 11.7% in Cinebench R15 (776 vs 695), by 11.7% in R20 (3234 vs 2896), and by 11.7% in R23 (7701 vs 6896).

Q: Does the Core i5-9400T's higher boost clock help it win any single-core tests?

A: No. Despite boosting to 3.40 GHz versus the Xeon's 2.20 GHz, the Core i5-9400T loses every single-core test. The Xeon leads by 12.4% in R15 single-core (109 vs 97), by 11.8% in R20 single-core (456 vs 408), and by 11.7% in R23 single-core (1087 vs 973).

Q: What is the biggest performance gap between these two CPUs?

A: The largest margin is in Cinebench R15 single-core, where the Xeon E5-4648 v3 leads by 12.4%. All other tests show a delta between 11.7% and 11.8%.

Q: Which processor has more cores and threads?

A: The Xeon E5-4648 v3 has 12 cores and 24 threads. The Core i5-9400T has 6 cores and 6 threads. The Xeon also has a larger shared L3 cache at 30 MB versus 9 MB.

Q: Does either processor support ECC memory?

A: Only the Xeon E5-4648 v3 supports ECC memory. The Core i5-9400T does not. The Xeon also uses a quad-channel memory bus with 59.7 GB/s bandwidth, while the Core i5 uses dual-channel with 42.7 GB/s.

Q: Which processor includes integrated graphics?

A: Only the Core i5-9400T includes integrated graphics, specifically Intel UHD 630. The Xeon E5-4648 v3 has no integrated graphics, which is typical for a server/workstation part.

Q: What are the TDP differences between the two?

A: The Core i5-9400T has a 35 W TDP, while the Xeon E5-4648 v3 has a 105 W TDP. This makes the Core i5 substantially easier to cool and power in a compact desktop system.