Xeon E5-1660 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 E5-1660 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 E5-1660 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 E5-1660

2012

Why buy it

Trade-offs

❌Smaller total L3 cache (15 MB vs 20 MB).
❌Launch MSRP is still $1,080 MSRP, while Xeon E5-2665 mostly shows up through inconsistent older-market listings.
❌No AVX-512 support for niche heavy compute workloads where it can matter.

Xeon E5-2665

2012

Why buy it

✅+33.3% larger total L3 cache (20 MB vs 15 MB).
✅Draws 115W instead of 130W, a 15W reduction.
✅100+% more PCIe lanes (40 vs 0) for storage and expansion-heavy builds.

Trade-offs

❌Lower PassMark (8,293 vs 8,324).

Quick Answers

So, is Xeon E5-1660 better than Xeon E5-2665?

Yes. Xeon E5-1660 is the better all-around CPU here. It gives you a 1.6% 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 E5-1660 is the better pick. According to our tests, it delivers 1.6% 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 E5-1660 is the stronger fit. You are getting 0.4% better PassMark, backed by 6 cores and 12 threads.

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

Xeon E5-1660 is the better buy right now. Xeon E5-1660 comes in at an unclear MSRP at $1,080 MSRP versus unclear MSRP, and it still gives you a 1.6% average FPS lead across 50 shared CPU game tests in our data. It is also 100.0% better value on MSRP (7.7 vs 0.0 PassMark/$), so you are getting the faster CPU without taking a value hit on paper.

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

Xeon E5-2665 makes more sense long term for 2026 and beyond. You are getting 33.3% larger total L3 cache (20 MB vs 15 MB) and AVX-512 support for heavier modern compute workloads. That makes it the safer long-term bet.

Xeon E5-1660 vs Xeon E5-2665 Technical Specifications

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

Xeon E5-1660

The Xeon E5-1660 is manufactured by Intel. It was released in 6 March 2012 (13 years ago). It is based on the Sandy Bridge-E (2011−2013) architecture. It features 6 cores and 12 threads. Base frequency is 3.3 GHz, with boost up to 3.9 GHz. L3 cache: 15360 kB (total). L2 cache: 256 kB (per core). Built on 32 nm process technology. Socket: LGA2011. Thermal design power (TDP): 130 Watt. Memory support: DDR3. Passmark benchmark score: 8,324 points. Launch price was $290.

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 E5-1660 packs 6 cores / 12 threads, while the Xeon E5-2665 offers 8 cores / 16 threads — the Xeon E5-2665 has 2 more cores. Boost clocks reach 3.9 GHz on the Xeon E5-1660 versus 3.1 GHz on the Xeon E5-2665 — a 22.9% clock advantage for the Xeon E5-1660 (base: 3.3 GHz vs 2.4 GHz). The Xeon E5-1660 uses the Sandy Bridge-E (2011−2013) architecture (32 nm), while the Xeon E5-2665 uses Sandy Bridge-EP (2012) (32 nm). In PassMark, the Xeon E5-1660 scores 8,324 against the Xeon E5-2665's 8,293 — a 0.4% lead for the Xeon E5-1660. L3 cache: 15360 kB (total) on the Xeon E5-1660 vs 20480 kB (total) on the Xeon E5-2665.

Feature	Xeon E5-1660	Xeon E5-2665
Cores / Threads	6 / 12	8 / 16+33%
Boost Clock	3.9 GHz+26%	3.1 GHz
Base Clock	3.3 GHz+38%	2.4 GHz
L3 Cache	15360 kB (total)	20480 kB (total)+33%
L2 Cache	256 kB (per core)	256 kB (per core)
Process	32 nm	32 nm
Architecture	Sandy Bridge-E (2011−2013)	Sandy Bridge-EP (2012)
PassMark	8,324	8,293

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Memory & Platform

Both processors use the LGA2011 socket with PCIe 2.0.

Feature	Xeon E5-1660	Xeon E5-2665
Socket	LGA2011	LGA2011
PCIe Generation	PCIe 2.0	PCIe 5.0+150%
Max RAM Speed	—	DDR3-1600
Max RAM Capacity	—	384 GB
RAM Channels	—	4
ECC Support	—	Yes
PCIe Lanes	—	40