Intel Core i5-1145G7E vs Intel Core i5-8259U Comparison

Head-to-Head Benchmarks

The benchmark data is unambiguous: the Intel Core i5-1145G7E wins every recorded comparison against the Intel Core i5-8259U. Across six Cinebench tests, the newer Tiger Lake processor leads by a consistent 12.8% to 13.6% margin. This uniformity suggests a broad architectural advantage rather than a workload-specific edge.

In Cinebench R15 multicore, the i5-1145G7E scores 757 against the i5-8259U's 667, a 13.5% lead. The single-core result follows the same pattern: 106 versus 94, a 12.8% advantage. Moving to Cinebench R20, the multicore gap widens slightly in absolute terms: 3156 versus 2781, again 13.5%. The R20 single-core test shows 445 versus 392, also 13.5%.

Cinebench R23 tells the same story with the largest absolute gap. The i5-1145G7E posts 7516 in multicore, while the i5-8259U manages 6622, a 13.5% difference. Single-core R23 shows 1061 against 934, a 13.6% margin, the largest relative win in the dataset. Notably, the i5-8259U has an additional Geekbench result (4168 multicore, 1207 single-core) not present for the i5-1145G7E, so no direct comparison is possible there.

The aggregate benchmark average confirms the hierarchy: the i5-1145G7E averages 2174 across all recorded tests, placing it in the 47th percentile of all CPUs. The i5-8259U averages 2108, sitting at the 46th percentile. The 66-point gap in average score is modest, but the head-to-head deltas show the i5-1145G7E is consistently ahead in every shared workload.

The nearest rivals for each chip place them in similar company. The i5-1145G7E sits within 0.8% of the AMD Ryzen 5 3400GE (2175), the Intel Core i7-1185GRE (2178, 0.2% ahead), the Intel Core i5-7640X (2167, 0.3% behind), and the Intel Core i7-5950HQ (2158, 0.8% behind). The i5-8259U is within 0.6% of the Intel Core i5-8500T (2110, 0.1% ahead), the AMD Ryzen 5 PRO 2400G (2101, 0.3% behind), the Intel Xeon E-2224G (2117, 0.4% ahead), and the Intel Core i3-8350K (2096, 0.6% behind). Both chips compete in the same performance tier, but the i5-1145G7E consistently outpoints its older counterpart.

Architecture Differences

The two processors come from different Intel generations and process nodes. The i5-1145G7E uses Tiger Lake-U architecture on a 10 nm process, while the i5-8259U is built on Coffee Lake-U with a 14 nm process. This node advantage partially explains the consistent 13%+ performance gap.

Core and thread counts are identical: both have 4 cores and 8 threads. However, cache layouts differ substantially. The i5-1145G7E has 80 KB of L1 per core, 1.25 MB of L2 per core, and 8 MB of shared L3. The i5-8259U has 64 KB of L1 per core, 256 KB of L2 per core, and 6 MB of shared L3. The Tiger Lake part offers both more L2 per core (approximately 4.9x) and more total L3 (33% more). Die size also differs: 144 mm² for the i5-1145G7E versus 126 mm² for the i5-8259U, reflecting the different transistor layouts and integrated components.

Clock speeds favor the older chip in base frequency but the newer chip in boost. The i5-8259U has a 2.30 GHz base clock, while the i5-1145G7E starts at 1.50 GHz. However, the i5-1145G7E boosts to 4.10 GHz, beating the i5-8259U's 3.80 GHz maximum. This higher boost clock, combined with the newer architecture, drives the single-core performance advantage.

Memory support diverges as well. The i5-1145G7E supports DDR4 and LPDDR4X, while the i5-8259U supports DDR4 only. Both use dual-channel memory buses. The i5-8259U has a recorded memory bandwidth of 38.4 GB/s; the i5-1145G7E has no bandwidth figure in the database. Neither chip supports ECC memory.

PCIe connectivity differs significantly. The i5-1145G7E provides Gen 4 with 4 lanes (CPU only), while the i5-8259U offers Gen 3 with 16 lanes (CPU only). The newer chip has faster per-lane bandwidth but fewer total lanes, a trade-off relevant for expansion options.

Integrated graphics also change. The i5-1145G7E uses Iris Xe Graphics G7 with 80 execution units. The i5-8259U pairs with Iris Pro Plus 655. Both target mobile platforms, but the Xe architecture is newer and designed for higher sustained performance.

Production status differs: the i5-1145G7E is listed as active, while the i5-8259U is end-of-life. Release dates reflect this: September 2020 for the i5-1145G7E, April 2018 for the i5-8259U. Sockets are incompatible: Intel BGA 1449 for the newer chip, Intel BGA 1526 for the older one.

Where Each One Wins

The i5-1145G7E wins every benchmark in the shared dataset, so the use-case split is largely about margins and secondary considerations rather than role reversal.

For single-threaded workloads, the i5-1145G7E is the clear choice. Its 4.10 GHz boost clock and newer Willow Cove cores deliver 12.8% to 13.6% higher scores across R15, R20, and R23 single-core tests. Applications that rely on responsive interaction, such as light office work, web browsing, or development tools, will favor this chip.

For multi-threaded tasks, the i5-1145G7E also leads, but the margin is identical (13.5% in R15, R20, and R23 multicore). The 8 MB L3 versus 6 MB helps sustain parallel workloads, as does the 1.25 MB per-core L2. Video encoding, compilation, or rendering on a mobile platform would benefit from this edge.

The i5-8259U retains a few advantages. Its 2.30 GHz base clock versus 1.50 GHz means it can sustain lower-intensity workloads without boosting as aggressively, potentially affecting power behavior over long sessions. The 16 PCIe Gen 3 lanes versus 4 Gen 4 lanes gives it more flexibility for connecting multiple devices, though the newer chip's Gen 4 speed per lane is higher. The i5-8259U also has a recorded memory bandwidth figure (38.4 GB/s), which may be relevant for memory-bound tasks, though the i5-1145G7E likely has similar or better bandwidth given its LPDDR4X support.

The i5-8259U has one benchmark result the i5-1145G7E lacks: Geekbench multicore (4168) and single-core (1207). Since the i5-1145G7E has no Geekbench score in the database, this is not a head-to-head win, but it shows the older chip can still produce competitive numbers in certain test suites.

The Verdict

The data points to the Intel Core i5-1145G7E as the superior processor for nearly all use cases. It wins all six shared Cinebench tests by margins between 12.8% and 13.6%, has a higher boost clock (4.10 GHz versus 3.80 GHz), more L2 and L3 cache, a newer 10 nm process node, and active production status. Its 47th percentile ranking versus 46th for the i5-8259U confirms the overall performance edge.

The i5-8259U is not without merit. Its higher base clock (2.30 GHz) and 16 PCIe Gen 3 lanes make it suitable for systems where sustained low-load operation or multiple device connections matter more than peak performance. It also has a smaller die (126 mm² versus 144 mm²), which might be relevant for compact designs, though the i5-1145G7E's 10 nm process likely offsets any physical size concerns.

For a buyer choosing between these two mobile processors, the i5-1145G7E is the rational pick unless the specific platform requires the i5-8259U's socket (BGA 1526) or its broader PCIe lane count. The newer chip offers consistently higher benchmark scores, faster single-thread and multi-thread performance, and a more modern feature set including Gen 4 PCIe and LPDDR4X support. The i5-8259U's end-of-life status further reduces its long-term viability.

FAQ

Q: Which processor has a higher boost clock?

A: The Intel Core i5-1145G7E boosts to 4.10 GHz, while the Intel Core i5-8259U reaches 3.80 GHz.

Q: What is the largest performance gap between the two in any benchmark?

A: The largest relative margin is in Cinebench R23 single-core, where the i5-1145G7E leads by 13.6% (1061 versus 934).

Q: Do both processors have the same core and thread count?

A: Yes, both have 4 cores and 8 threads.

Q: Which processor has more L3 cache?

A: The i5-1145G7E has 8 MB of shared L3 cache, while the i5-8259U has 6 MB.

Q: Are the two processors compatible with the same socket?

A: No, the i5-1145G7E uses Intel BGA 1449, while the i5-8259U uses Intel BGA 1526.

Q: Which processor is still in production?

A: The i5-1145G7E is listed as active, while the i5-8259U is end-of-life.

Specification Differences

| Specification | Intel Core i5-1145G7E | Intel Core i5-8259U |

|---|---|---|

| Base Clock | 1500.00 MHz | 2300.00 MHz |

| Boost Clock | 4.10 GHz | 3.80 GHz |

| Socket | Intel BGA 1449 | Intel BGA 1526 |

| Architecture | Tiger Lake | Coffee Lake |

| Process Node | 10 nm | 14 nm |

| Die Size | 144 mm² | 126 mm² |

| L1 Cache | 80 KB (per core) | 64 KB (per core) |

| L2 Cache | 1.25 MB (per core) | 256 KB (per core) |

| L3 Cache | 8 MB (shared) | 6 MB (shared) |

| Memory Support | DDR4, LPDDR4X | DDR4 |

| Memory Bandwidth | Not recorded | 38.4 GB/s |

| PCIe | Gen 4, 4 Lanes (CPU only) | Gen 3, 16 Lanes (CPU only) |

| Integrated Graphics | Iris Xe Graphics G7 80EU | Iris Pro Plus 655 |

| Production Status | Active | End-of-life |

| Release Date | 2020-09-01 | 2018-04-04 |

| Launch MSRP | $312 | $320 |

| Part Number | SRK0Z | SRCKBSRCUU |