Intel Core i5-1145GRE vs Intel Core i5-8400T Comparison

The Intel Core i5-1145GRE and Intel Core i5-8400T are both 45th-percentile performers in the database, yet they achieve that standing through very different designs. The i5-1145GRE is a low-power mobile Tiger Lake part with four cores and eight threads, while the i5-8400T is a desktop Coffee Lake chip with six cores and six threads. Benchmark results show a clear overall winner in the i5-1145GRE, which takes all six head-to-head Cinebench tests, but the choice between them depends on whether the workload favors raw multi-threaded capacity or per-core efficiency and platform features.

Where Each One Wins

The Intel Core i5-1145GRE wins every recorded benchmark comparison. In Cinebench R15 multicore, it scores 705 against 633 for the i5-8400T, a delta of 11.4%. The single-core R15 result is 99 versus 89, an 11.2% advantage. This pattern repeats across R20 and R23, with the multicore delta sitting at 11.4% and the single-core delta at 11.3% to 11.5%. The data shows that the i5-1145GRE is faster in both single-threaded and multi-threaded rendering tests, despite having two fewer physical cores.

The Intel Core i5-8400T does not have a single winning benchmark in the recorded head-to-head set. Its strengths lie outside the Cinebench suite. It supports 16 PCIe Gen 3 lanes from the CPU, versus only 4 Gen 4 lanes on the i5-1145GRE, making it the more practical choice for systems that need to attach multiple expansion devices directly to the processor. It also lists a memory bandwidth figure of 42.7 GB/s, a specification the i5-1145GRE does not provide in the database. For a desktop build with discrete GPUs or NVMe storage, the i5-8400T offers a wider PCIe interface, even though its compute scores trail the mobile part.

Architecture Differences

The two processors come from different Intel generations and process nodes. The i5-1145GRE uses Tiger Lake-U silicon built on a 10 nm process, while the i5-8400T is Coffee Lake on a 14 nm process. The die sizes are close, 144 mm² for the i5-1145GRE and 154 mm² for the i5-8400T, but the core configurations diverge sharply. The i5-1145GRE has 4 cores and 8 threads with a base clock of 1500 MHz and a boost clock of 4.10 GHz. The i5-8400T has 6 cores and 6 threads, a base clock of 1700 MHz, and a boost of 3.30 GHz. The i5-1145GRE boosts much higher, which explains its single-core dominance, while the i5-8400T relies on two additional physical cores to stay competitive in multicore tests.

Cache layouts differ as well. The i5-1145GRE allocates 80 KB of L1 and 1.25 MB of L2 per core, with 8 MB of shared L3. The i5-8400T has 64 KB of L1 and 256 KB of L2 per core, but a larger 9 MB shared L3. The per-core L2 advantage of the i5-1145GRE is substantial, 1.25 MB versus 256 KB, which aids its higher boost clock in latency-sensitive single-threaded work. The i5-8400T counters with slightly more total L3, 9 MB versus 8 MB.

Memory support also separates them. The i5-1145GRE supports DDR4 and LPDDR4X in dual-channel mode and includes ECC memory support. The i5-8400T supports only DDR4 in dual-channel mode and lacks ECC. Integrated graphics differ: the i5-1145GRE carries Iris Xe Graphics G7 with 80 execution units, while the i5-8400T has the older UHD Graphics 630. The Tiger Lake part also uses a BGA 1449 socket, typical of soldered mobile designs, whereas the i5-8400T uses Socket 1151, which allows for desktop installation and replacement.

Head-to-Head Benchmarks

The largest recorded margin belongs to Cinebench R23 single-core, where the i5-1145GRE scores 988 against 886 for the i5-8400T, a delta of 11.5%. This is the most lopsided result in the entire head-to-head set. R20 single-core follows closely: 414 versus 372, an 11.3% delta. R15 single-core shows 99 versus 89, an 11.2% delta. These numbers confirm that the Tiger Lake chip delivers roughly 11% to 12% more single-threaded performance than the older Coffee Lake part, a direct consequence of the higher 4.10 GHz boost clock and newer architecture.

Multicore results are evenly clustered around the same margin. Cinebench R15 multicore, R20 multicore, and R23 multicore all show an 11.4% delta, with scores of 705 versus 633, 2940 versus 2638, and 7001 versus 6282 respectively. The consistency of the 11.4% multicore margin is notable: the i5-8400T's two extra cores cannot overcome the i5-1145GRE's higher clocks and per-core efficiency, at least in these rendering workloads. The i5-1145GRE also has 8 threads against 6, which helps in Cinebench's scaling behavior even with fewer physical cores.

Average benchmark scores place the two close together overall. The i5-1145GRE has an average score of 2025, and the i5-8400T sits at 2001, a difference of roughly 24 points that corresponds to about 1.2% of the i5-1145GRE's score. Nearest rivals for the i5-1145GRE include the Intel Core i5-1130G7 with an average of 2026, the Xeon E3-1260L v5 at 2029, the Xeon E3-1280 v5 at 2029, and the Xeon E3-1240 v5 at 2030. The i5-8400T's nearest rivals are the AMD Ryzen 7 2800H at 2002, the Intel Core i5-8400H at 2003, the Xeon D-1712TR at 2004, and the Intel Core i5-8300H at 2005. Both chips sit in a dense performance band where a few points separate adjacent processors, but their head-to-head results are unambiguous.

FAQ

Q: Which processor is faster in Cinebench tests?

A: The Intel Core i5-1145GRE wins all six Cinebench R15, R20, and R23 multicore and single-core tests. Multicore deltas range from 11.4% to 11.5%, and single-core deltas from 11.2% to 11.5%.

Q: Does the i5-8400T ever beat the i5-1145GRE in the recorded benchmarks?

A: No, the i5-8400T has zero wins in the head-to-head benchmark set. The i5-1145GRE wins all six recorded comparisons.

Q: What are the core counts and thread counts?

A: The i5-1145GRE has 4 cores and 8 threads. The i5-8400T has 6 cores and 6 threads.

Q: How does memory support differ between the two processors?

A: The i5-1145GRE supports DDR4 and LPDDR4X with ECC memory support enabled. The i5-8400T supports only DDR4 and does not support ECC memory.

Q: Which processor has more PCIe lanes from the CPU?

A: The i5-8400T provides 16 PCIe Gen 4 lanes available from the CPU, while the i5-1145GRE provides 4 Gen 4 lanes.

Q: What is the production status of each chip?

A: The i5-1145GRE is listed as Active production status, while the i5-8400T is listed as End-of-life production status.

The Verdict

Choose the Intel Core i5-1145GRE if the workload is compute-bound rendering or single-threaded applications. It wins every Cinebench test in the database, offers ECC memory, supports LPDDR4X, and includes Iris Xe Graphics G7 80EU. Its 10 nm process and higher boost clock of 4.10 GHz deliver 11.4% to 11.5% better multicore scores and 11.2% to 11.5% better single-core scores than the i5-8400T. The 28 W TDP and BGA 1449 socket make it a mobile-oriented part, but benchmark results show it outruns the older desktop chip in CPU-bound tasks.

Choose the Intel Core i5-8400T if the platform needs more direct PCIe connectivity. Its 16 PCIe Gen 3 lanes, 35 W TDP, and Socket 1151 design suit desktop builds with multiple expansion cards. It also provides a stated memory bandwidth of 42.7 GB/s and a larger 9 MB shared L3 cache. However, the recorded data shows it falls behind the i5-1145GRE in every Cinebench comparison, with multicore deficits of 11.4% and single-core deficits of 11.2% to 11.5%. Its 6 cores and 6 threads do not translate into a win in these tests, and its production status is End-of-life.

The average benchmark scores are nearly identical, 2025 for the i5-1145GRE versus 2001 for the i5-8400T, and both land in the 45th percentile of all CPUs. In the head-to-head set, one processor wins decisively, and it is not the one with more cores. The i5-1145GRE is the faster CPU in rendering workloads; the i5-8400T is the better fit for a desktop platform with broad PCIe lane requirements.

Specification Differences

The i5-1145GRE uses a 10 nm process node, a Tiger Lake-U architecture, and a generation identifier of Core i5 (Willow Cove-U) architecture, with a die size of 144 mm², 4 cores and 8 threads, a base clock of 1500 MHz, a boost clock of 4.10 GHz, a TDP of 28 W, and an Intel BGA 1449 socket. Cache per core is 80 KB L1 cache per core and 1.25 MB L2 cache per core L2 cache, with 8 MB shared L3 cache shared cache. Memory support covers DDR4 and LPDDR4X with dual-channel memory bus and ECC memory support enabled. PCIe Gen 4.0, 4 Lanes CPU-only lanes, Iris Xe Graphics G7 80EU integrated graphics, and production status listed as Active.

The i5-8400T uses a 14 nm process node, a Coffee Lake architecture, and a generation identifier of Core i5 (Coffee Lake), with a die size of 154 mm², 6 cores and 6 threads, a base clock of 1700 MHz, a boost clock of 3.30 GHz, a TDP of 35 W, and an Intel Socket 1151. Cache per core is 64 KB L1 cache per core and 256 KB L2 cache per core L2 cache, with 9 MB shared L3 cache shared cache. Memory support covers DDR4 with dual-channel memory bus and a memory bandwidth of 42.7 GB/s, no ECC memory support, PCIe Gen 3.0, 16 Lanes CPU-only lanes, UHD Graphics 630 integrated graphics, and production status listed as End-of-life.