Intel Core i7-3540M vs Intel Core i7-920 Comparison

The Intel Core i7-920 and the Intel Core i7-3540M make for one of the more striking matchups in the database: a desktop heavyweight from the Nehalem era against a mobile dual-core from Ivy Bridge. On paper their raw throughput is nearly identical, and the recorded benchmark data confirms it, with the two processors separated by only a few percentage points across every test. What differs is how each one gets there, and what that means for the platform built around it.

Head-to-Head Benchmarks

The head-to-head record is a clean sweep for the mobile part: the Intel Core i7-3540M wins all five recorded contests against the Intel Core i7-920, and each win is narrow.

In Cinebench R15 multi-core, the i7-3540M scores 254 against 246 for the i7-920, a gap of 3.1 percent. Cinebench R20 multi-core tells the same story: 1060 versus 1025, or 3.3 percent in favor of the i7-3540M. The R20 single-core result is 149 against 144, a 3.4 percent advantage for the Ivy Bridge chip, and Cinebench R23 repeats the pattern almost exactly, with the i7-3540M ahead 2525 to 2442 in multi-core (3.3 percent) and 356 to 344 in single-core (3.4 percent).

The consistency is the notable part. Across five tests spanning three Cinebench generations, the delta never leaves the 3.1 to 3.4 percent band. There is no test where the i7-920's extra cores and threads translate into a lead, and no test where the i7-3540M's much higher clock speeds break away decisively. The two chips are, for benchmark purposes, performance twins.

The aggregate scores agree. The i7-920 averages 840 and sits at the 22nd percentile versus all CPUs in the database; the i7-3540M averages 867 and sits at the 23rd percentile. Their nearest-rivals lists barely overlap in character but not in score: the i7-920's closest comparators are the Intel Xeon X5470 (avg score 839, delta 0.1 percent), the Intel Core i5-3380M (838, 0.2 percent), the Intel Core i5-5200U (838, 0.3 percent), and the AMD FX-8800P (843, -0.3 percent). The i7-3540M's rivals are the Intel Xeon X3460 (866, 0.1 percent), the Intel Core i5-3470T (863, 0.4 percent), the Intel Atom C5315 (871, -0.5 percent), and the AMD Athlon PRO 3045B (872, -0.6 percent). Both chips occupy the same tier of the historical performance ladder.

The i7-3540M also has Geekbench entries in the database, 1160 multi-core and 565 single-core, for which no comparable i7-920 results are recorded.

Architecture Differences

The gulf between these two parts is architectural, not performance-related, and it starts with the process node. The i7-920 is a Bloomfield chip built on Intel's 45 nm process, with 731 million transistors on a 263 mm² die. The i7-3540M is an Ivy Bridge part on 22 nm, with a die size of just 118 mm², less than half the area, on a node two full generations denser.

Core topology is inverted. The i7-920 is a 4-core, 8-thread desktop processor with a base clock of 2.67 GHz and a boost clock of 2.93 GHz. The i7-3540M is a 2-core, 4-thread mobile processor with a base clock of 3.00 GHz and a boost clock of 3.70 GHz. The desktop chip doubles the cores and threads; the mobile chip responds with substantially higher frequencies and the newer Ivy Bridge microarchitecture, which is why the half-sized part matches the Bloomfield flagship's throughput.

Cache differs too. The i7-920 carries 8 MB of shared L3, against 4 MB shared L3 on the i7-3540M. Per-core L1 and L2 are identical in the recorded data: 64 KB L1 and 256 KB L2 per core on both.

Memory support is DDR3 on both, but the desktop part uses a triple-channel memory bus while the mobile part is dual-channel. The i7-920 connects through PCI Express Gen 2; no PCIe data is recorded for the i7-3540M. The mobile chip integrates Intel HD 4000 graphics, while the i7-920 has no integrated graphics recorded at all.

Power and platform scale accordingly. The i7-920 is rated at 130 W TDP on Socket 1366; the i7-3540M is rated at 35 W TDP on Socket G2 (988B). That is a dramatic efficiency gap, and it frames the whole comparison: the i7-3540M delivers equivalent benchmark performance at roughly a quarter of the rated power. Neither chip has an unlocked multiplier, and neither supports ECC memory in the recorded data.

Release timing also matters. The i7-920 launched on November 16, 2008, and is flagged as end-of-life. The i7-3540M followed on January 7, 2013, more than four years later.

FAQ

Q: Which CPU is faster overall?

A: The Intel Core i7-3540M, but only barely. It wins all five head-to-head benchmarks by 3.1 to 3.4 percent, and its average database score of 867 edges out the i7-920's 840.

Q: Does the i7-920's 4 cores beat the i7-3540M's 2 cores in multi-core workloads?

A: No. Despite having twice the cores (4 versus 2) and threads (8 versus 4), the i7-920 loses every multi-core Cinebench test, including 2442 versus 2525 in Cinebench R23. The i7-3540M's higher clocks and newer Ivy Bridge architecture fully offset the core-count deficit.

Q: Which CPU is more power efficient?

A: The i7-3540M, by a wide margin. It is rated at 35 W TDP versus 130 W for the i7-920, while delivering equivalent benchmark performance.

Q: Do these CPUs use the same socket?

A: No. The i7-920 uses Intel Socket 1366; the i7-3540M uses Intel Socket G2 (988B). They are not interchangeable and require entirely different platforms.

Q: Does either CPU have integrated graphics?

A: Only the i7-3540M, which integrates Intel HD 4000. No integrated graphics are recorded for the i7-920, meaning a discrete GPU is required on that platform.

Q: How do their cache sizes compare?

A: The i7-920 has 8 MB of shared L3 cache, double the i7-3540M's 4 MB. Per-core L1 (64 KB) and L2 (256 KB) are identical.

The Verdict

On pure performance data, the choice is straightforward: the i7-3540M is the marginally better processor, winning every recorded benchmark, and it does so at a fraction of the power draw. For any use case governed by the numbers in this database, render throughput, single-thread speed, or efficiency, the Ivy Bridge mobile chip is the pick.

The i7-920's case rests entirely on platform characteristics rather than benchmark scores. Its triple-channel DDR3 memory bus, PCI Express Gen 2 connectivity, larger 8 MB L3 cache, and the wider headroom implied by a 130 W desktop envelope make it the foundation of a full desktop build, albeit one that is now end-of-life and socket-locked to the 1366 platform. Its performance percentile, 22 versus 23, is effectively identical to the i7-3540M's.

Neither chip is competitive in the modern landscape; both sit in the low twenties percentile-wise against all CPUs in the database. But as a snapshot of four years of Intel progress, the pairing is unusually clean: half the cores, half the die area, a quarter of the TDP, and slightly better scores across the board.

Specification Differences

• Market segment: Desktop (i7-920) versus Mobile (i7-3540M)
• Architecture / codename: Nehalem, Bloomfield versus Ivy Bridge
• Process node: 45 nm versus 22 nm
• Cores / threads: 4 cores, 8 threads versus 2 cores, 4 threads
• Base / boost clock: 2.67 / 2.93 GHz versus 3.00 / 3.70 GHz
• TDP: 130 W versus 35 W
• Socket: Intel Socket 1366 versus Intel Socket G2 (988B)
• L3 cache: 8 MB shared versus 4 MB shared
• Memory bus: Triple-channel versus dual-channel (both DDR3)
• PCIe: Gen 2 versus not recorded
• Integrated graphics: none recorded versus Intel HD 4000
• Die size / transistors: 263 mm² and 731 million transistors versus 118 mm², transistors not recorded
• Release date: November 16, 2008 versus January 7, 2013
• Production status: End-of-life versus not recorded
• Part number: SLBCHSLBEJ versus SR0X6

Fields where the two match: manufacturer, L1 and L2 cache per core, DDR3 memory support, ECC disabled, locked multiplier, and identical average-rival proximity.

Where Each One Wins

Where the i7-3540M wins: everywhere in the recorded benchmark data. It leads in all multi-core Cinebench tests (R15: 254 to 246; R20: 1060 to 1025; R23: 2525 to 2442), all single-core tests (R20: 149 to 144; R23: 356 to 344), and by extension any workload that values efficiency, given the 35 W versus 130 W TDP gap. Its Intel HD 4000 graphics also make it self-sufficient for display output without a discrete GPU. Users prioritizing per-thread responsiveness or battery-constrained operation should follow the benchmark verdict here.

Where the i7-920 wins: on paper specifications only. Twice the physical cores and threads, double the shared L3 cache, triple-channel memory, and PCI Express Gen 2 lanes give it the broader desktop platform. None of that converted into a single benchmark win in the recorded data, but for workloads that scale with memory bandwidth or platform I/O rather than the tested render throughput, the Socket 1366 platform offers capabilities the mobile part simply does not have. It remains a desktop-building proposition; the i7-3540M remains a laptop one.