Xeon E3-1240 v5 vs Xeon E5-2665

PassMark CPU Mark evaluates processor speed through complex mathematical computations. It provides a reliable metric to compare multi-core performance, where higher scores indicate faster processing for multitasking, gaming, and heavy workloads.

Xeon E3-1240 v5 vs Xeon E5-2665 FPS Benchmarks

Predicted gaming performance across popular games. Tested paired with GeForce RTX 5090 to isolate CPU performance.

Search any supported game below to compare 1080p FPS for both components.

Xeon E3-1240 v5 vs Xeon E5-2665: Pros, Cons & Final Verdict

See where each CPU makes more sense in practice: gaming, heavier work, platform cost, power draw, and upgrade path.

Xeon E3-1240 v5

2015

Why buy it

✅Draws 80W instead of 115W, a 35W reduction.

Trade-offs

❌Worse for gaming: lower average FPS than Xeon E5-2665 across 50 shared CPU benchmark tests.
❌Lower PassMark (8,258 vs 8,293).
❌Smaller total L3 cache (8 MB vs 20 MB).

Xeon E5-2665

2012

Why buy it

✅Better for gaming: +5.0% higher average FPS across 50 shared CPU benchmark tests.
✅+150% larger total L3 cache (20 MB vs 8 MB).
✅100+% more PCIe lanes (40 vs 0) for storage and expansion-heavy builds.

Trade-offs

❌43.8% higher power demand at 115W vs 80W.

Quick Answers

So, is Xeon E5-2665 better than Xeon E3-1240 v5?

Yes. Xeon E5-2665 is the better all-around CPU here. It gives you a 5.0% average FPS lead across 50 shared CPU game tests in our data and 0.4% better PassMark, which is enough to make it the stronger overall pick.

Which one is better for gaming?

If gaming is the priority, Xeon E5-2665 is the better pick. According to our tests, it delivers 5.0% more average FPS across 50 shared CPU game tests.

Which one is better for streaming, content creation, and heavy multitasking?

For streaming, content creation, and heavier multitasking, Xeon E5-2665 is the stronger fit. You are getting 0.4% better PassMark, backed by 8 cores and 16 threads. It also has the larger cache pool with 150% larger total L3 cache (20 MB vs 8 MB).

Which one is the smarter buy today, not just the cheaper CPU?

Xeon E5-2665 still makes the most sense overall. Xeon E5-2665 comes in at an unclear MSRP at unclear MSRP versus unclear MSRP, and it still gives you a 5.0% average FPS lead across 50 shared CPU game tests in our data.

Which one is more future-proof for 2026 and beyond?

Xeon E3-1240 v5 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2015 vs 2012). That makes it the safer long-term bet.

Xeon E3-1240 v5 vs Xeon E5-2665 Technical Specifications

Side-by-side specs, architecture details, clocks, memory, power, and platform differences.

Xeon E3-1240 v5

The Xeon E3-1240 v5 is manufactured by Intel. It was released in 19 October 2015 (10 years ago). It is based on the Skylake-DT (2015) architecture. It features 4 cores and 8 threads. Base frequency is 3.5 GHz, with boost up to 3.9 GHz. L3 cache: 8 MB (total). L2 cache: 256 kB (per core). Built on 14 nm process technology. Socket: LGA1151, LGA2011. Thermal design power (TDP): 80 Watt. Memory support: DDR4-1866/2133, DDR3L-1333/1600. Passmark benchmark score: 8,258 points. Launch price was $282.

Xeon E5-2665

The Xeon E5-2665 is manufactured by Intel. It was released in 6 March 2012 (13 years ago). It is based on the Sandy Bridge-EP (2012) architecture. It features 8 cores and 16 threads. Base frequency is 2.4 GHz, with boost up to 3.1 GHz. L3 cache: 20480 kB (total). L2 cache: 256 kB (per core). Built on 32 nm process technology. Socket: LGA2011. Thermal design power (TDP): 115 Watt. Memory support: DDR3. Passmark benchmark score: 8,293 points. Launch price was $142.

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Processing Power

The Xeon E3-1240 v5 packs 4 cores / 8 threads, while the Xeon E5-2665 offers 8 cores / 16 threads — the Xeon E5-2665 has 4 more cores. Boost clocks reach 3.9 GHz on the Xeon E3-1240 v5 versus 3.1 GHz on the Xeon E5-2665 — a 22.9% clock advantage for the Xeon E3-1240 v5 (base: 3.5 GHz vs 2.4 GHz). The Xeon E3-1240 v5 uses the Skylake-DT (2015) architecture (14 nm), while the Xeon E5-2665 uses Sandy Bridge-EP (2012) (32 nm). In PassMark, the Xeon E3-1240 v5 scores 8,258 against the Xeon E5-2665's 8,293 — a 0.4% lead for the Xeon E5-2665. L3 cache: 8 MB (total) on the Xeon E3-1240 v5 vs 20480 kB (total) on the Xeon E5-2665.

Feature	Xeon E3-1240 v5	Xeon E5-2665
Cores / Threads	4 / 8	8 / 16+100%
Boost Clock	3.9 GHz+26%	3.1 GHz
Base Clock	3.5 GHz+46%	2.4 GHz
L3 Cache	8 MB (total)	20480 kB (total)+150%
L2 Cache	256 kB (per core)	256 kB (per core)
Process	14 nm-56%	32 nm
Architecture	Skylake-DT (2015)	Sandy Bridge-EP (2012)
PassMark	8,258	8,293

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Memory & Platform

The Xeon E3-1240 v5 uses the LGA1151, LGA2011 socket (PCIe 3.0), while the Xeon E5-2665 uses LGA2011 (PCIe 5.0) — making them incompatible on the same motherboard.

Feature	Xeon E3-1240 v5	Xeon E5-2665
Socket	LGA1151, LGA2011	LGA2011
PCIe Generation	PCIe 3.0	PCIe 5.0+67%
Max RAM Speed	—	DDR3-1600
Max RAM Capacity	—	384 GB
RAM Channels	—	4
ECC Support	—	Yes
PCIe Lanes	—	40