Intel Core i5-2500 vs Intel Core i7-8665UE Comparison

The Verdict

The benchmark data positions these two Intel processors as closely matched overall, yet they serve fundamentally different markets. The Intel Core i5-2500, a Sandy Bridge desktop part, and the Intel Core i7-8665UE, a Whiskey Lake mobile part, are separated by only 2.3% in average benchmark score (1220 vs 1193). However, in every recorded head-to-head benchmark, the i7-8665UE wins, with a consistent margin of 15.6% to 15.7% across all Cinebench tests. The i5-2500 holds a slight edge in the database percentile ranking (34th vs 33rd percentile of all CPUs), but the i7-8665UE delivers superior raw performance in every measured workload. For users prioritizing single-threaded responsiveness and multi-core throughput, the i7-8665UE is the clear choice from the data. The i5-2500, while older and less efficient, remains competitive in aggregate score but loses every direct comparison. The i7-8665UE is the better performer; the i5-2500 is the better value only if legacy desktop compatibility matters more than speed.

Where Each One Wins

The i7-8665UE wins every benchmark in the database, so its strengths are unambiguous. In Cinebench R15 multi-core, it scores 415 versus 350 for the i5-2500, a 15.7% advantage. In Cinebench R20 multi-core, the margin is 1732 versus 1461 (15.6% ahead), and in single-core R20 it leads 244 versus 206 (15.6% ahead). The same pattern holds in Cinebench R23: multi-core 4124 versus 3479, single-core 582 versus 491, both with a 15.6% delta. The i5-2500 has no benchmark wins in the database. The only area where the i5-2500 is not behind is in the aggregate average score, where it sits at 1220 versus 1193 for the i7-8665UE, a difference of 2.3% in its favor. This aggregate number is skewed by the i5-2500 having Geekbench results (multi-core 1883, single-core 670) while the i7-8665UE lacks Geekbench entries. For users who rely on Geekbench, the i5-2500 appears stronger, but for Cinebench workloads, the i7-8665UE is consistently faster. The i7-8665UE also has a lower thermal envelope (15W vs 95W), which is not directly benchmarked but indicates better efficiency for sustained mobile workloads.

Architecture Differences

The two CPUs are separated by seven years of Intel architecture evolution. The i5-2500 uses Sandy Bridge on a 32 nm process, with 4 cores and 4 threads, while the i7-8665UE uses Whiskey Lake on a 14 nm process, with 4 cores and 8 threads thanks to Hyper-Threading. The i5-2500 has a base clock of 3.30 GHz and a boost of 3.70 GHz, while the i7-8665UE has a much lower base clock of 1700.00 MHz (1.7 GHz) but a higher boost of 4.40 GHz. The i7-8665UE compensates for its low base clock with aggressive boosting, which explains its consistent lead in both single and multi-threaded tests. Cache configurations differ: the i5-2500 has 6 MB of shared L3 cache, while the i7-8665UE has 8 MB shared L3. Both have the same per-core L1 (64 KB) and L2 (256 KB) cache. The memory support differs: the i5-2500 supports DDR3 only, while the i7-8665UE supports DDR3 and DDR4, with a memory bandwidth of 38.4 GB/s (the i5-2500 has no recorded bandwidth figure). Integrated graphics differ: the i5-2500 has Intel HD 2000, the i7-8665UE has UHD Graphics 620, though no graphics benchmarks are recorded. Both use PCIe Gen 3 with 16 lanes (CPU only). The i5-2500 is a desktop part (Socket 1155) with a 95W TDP, while the i7-8665UE is a mobile part (BGA 1528) with a 15W TDP. The i5-2500 has 1,160 million transistors on a 216 mm² die; the i7-8665UE has no transistor or die size data. Neither CPU has an unlocked multiplier. The i5-2500 was released in 2011, the i7-8665UE in 2018. Both are end-of-life.

FAQ

Q: Which CPU has more threads?

A: The Intel Core i7-8665UE has 8 threads, while the Intel Core i5-2500 has 4 threads. Both have 4 cores.

Q: How much faster is the i7-8665UE in multi-core Cinebench R23?

A: The i7-8665UE scores 4124 versus 3479 for the i5-2500, a 15.6% advantage.

Q: Does the i5-2500 win any benchmark in the database?

A: No. The i7-8665UE wins all five recorded head-to-head benchmarks. The i5-2500 only has a higher average score (1220 vs 1193) due to including Geekbench results.

Q: What is the TDP difference?

A: The i5-2500 has a 95W TDP, while the i7-8665UE has a 15W TDP, making the mobile part significantly more power-efficient.

Q: Which CPU has newer memory support?

A: The i7-8665UE supports DDR3 and DDR4 with a 38.4 GB/s memory bandwidth. The i5-2500 only supports DDR3 and has no recorded bandwidth.

Q: What is the launch MSRP of the i7-8665UE?

A: The launch MSRP is $409. The i5-2500 has no recorded launch MSRP.

Q: How do the single-core scores compare?

A: In Cinebench R23 single-core, the i7-8665UE scores 582 versus 491 for the i5-2500, a 15.6% lead. In R20 single-core, it is 244 versus 206, also a 15.6% lead.

Head-to-Head Benchmarks

The head-to-head data is unambiguous: the i7-8665UE wins every recorded test. The largest margin is in Cinebench R15 multi-core, where the i7-8665UE scores 415 versus 350 for the i5-2500, a 15.7% delta. This is the only test where the margin exceeds 15.6%; all other tests show exactly 15.6% differences. In Cinebench R20 multi-core, the scores are 1732 versus 1461, and in R20 single-core, 244 versus 206. In Cinebench R23 multi-core, the i7-8665UE reaches 4124 versus 3479, and in R23 single-core, 582 versus 491. The consistency of the delta across all tests suggests the i7-8665UE has a systematic advantage in both single and multi-threaded workloads. The i5-2500, despite its higher base clock (3.30 GHz vs 1.70 GHz), cannot overcome the i7-8665UE's higher boost clock (4.40 GHz vs 3.70 GHz) and additional threads. The i7-8665UE's 8 threads allow it to process more parallel work, which is reflected in the multi-core results. For single-core, the boost clock advantage of 0.70 GHz is decisive. The i5-2500's Geekbench scores (multi-core 1883, single-core 670) are not part of the head-to-head table, so they cannot be directly compared. In aggregate, the i5-2500 averages 1220 across all its benchmarks, while the i7-8665UE averages 1193, but this aggregate includes different test sets. The head-to-head Cinebench results are the only apples-to-apples comparisons, and they uniformly favor the i7-8665UE. The measured deltas range from 15.6% to 15.7%, which is a substantial margin for CPUs that otherwise sit close in the overall percentile ranking. The i5-2500's nearest rivals are the i7-3632QM (0.1% ahead), Pentium Silver N6005 (0.2% ahead), Xeon E5-1607 v3 (0.6% ahead), and i3-7300T (0.8% ahead). The i7-8665UE's nearest rivals are the i3-4170 (0% delta), Athlon PRO 300U (0% delta), Opteron 3365 (0.1% behind), and Opteron 6234 (0.2% ahead). These rivalry patterns place both CPUs in the same performance tier, but the head-to-head tests reveal the i7-8665UE as the stronger part within that tier.