Xeon E3-1275 v5 vs Xeon E5-1660

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 E3-1275 v5 vs Xeon E5-1660 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 E3-1275 v5 vs Xeon E5-1660: Pros, Cons & Final Verdict

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

Xeon E3-1275 v5

2015

Why buy it

✅Draws 80W instead of 130W, a 50W reduction.

Trade-offs

❌Lower PassMark (8,291 vs 8,324).
❌Smaller total L3 cache (8 MB vs 15 MB).

Xeon E5-1660

2012

Why buy it

✅+0.4% higher PassMark.
✅+87.5% larger total L3 cache (15 MB vs 8 MB).

Trade-offs

❌Launch MSRP is still $1,080 MSRP, while Xeon E3-1275 v5 mostly shows up through inconsistent older-market listings.
❌62.5% higher power demand at 130W vs 80W.

Quick Answers

So, is Xeon E3-1275 v5 better than Xeon E5-1660?

It depends on what you want from the system. For gaming, Xeon E3-1275 v5 is ahead with a 1.1% average FPS lead across 50 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Xeon E5-1660 pulls ahead with 0.4% better PassMark. Xeon E5-1660 also has the bigger cache pool with 87.5% larger total L3 cache (15 MB vs 8 MB).

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. It also has the larger cache pool with 87.5% larger total L3 cache (15 MB vs 8 MB).

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

Xeon E3-1275 v5 is still the faster CPU overall, but Xeon E5-1660 is easier to justify if budget matters more than peak performance. Xeon E3-1275 v5 comes in at an unclear MSRP at unclear MSRP versus $1,080 MSRP, and it still gives you a 1.1% average FPS lead across 50 shared CPU game tests in our data. The compromise is that Xeon E5-1660 is still stronger for heavier multi-core work with 0.4% better PassMark. Xeon E5-1660 is also 100.0% better value on MSRP (7.7 vs 0.0 PassMark/$), which is why it can still make sense for tighter-budget builds on paper.

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

Xeon E3-1275 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 E3-1275 v5 vs Xeon E5-1660 Technical Specifications

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

Xeon E3-1275 v5

The Xeon E3-1275 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 3.6 GHz, with boost up to 4 GHz. L3 cache: 8 MB (total). L2 cache: 256 kB (per core). Built on 14 nm process technology. Socket: LGA1151. Thermal design power (TDP): 80 Watt. Memory support: DDR4-1866/2133, DDR3L-1333/1600. Passmark benchmark score: 8,291 points. Launch price was $350.

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.

⚡

Processing Power

The Xeon E3-1275 v5 packs 4 cores / 8 threads, while the Xeon E5-1660 offers 6 cores / 12 threads — the Xeon E5-1660 has 2 more cores. Boost clocks reach 4 GHz on the Xeon E3-1275 v5 versus 3.9 GHz on the Xeon E5-1660 — a 2.5% clock advantage for the Xeon E3-1275 v5 (base: 3.6 GHz vs 3.3 GHz). The Xeon E3-1275 v5 uses the Skylake-DT (2015) architecture (14 nm), while the Xeon E5-1660 uses Sandy Bridge-E (2011−2013) (32 nm). In PassMark, the Xeon E3-1275 v5 scores 8,291 against the Xeon E5-1660's 8,324 — a 0.4% lead for the Xeon E5-1660. L3 cache: 8 MB (total) on the Xeon E3-1275 v5 vs 15360 kB (total) on the Xeon E5-1660.

Feature	Xeon E3-1275 v5	Xeon E5-1660
Cores / Threads	4 / 8	6 / 12+50%
Boost Clock	4 GHz+3%	3.9 GHz
Base Clock	3.6 GHz+9%	3.3 GHz
L3 Cache	8 MB (total)	15360 kB (total)+88%
L2 Cache	256 kB (per core)	256 kB (per core)
Process	14 nm-56%	32 nm
Architecture	Skylake-DT (2015)	Sandy Bridge-E (2011−2013)
PassMark	8,291	8,324

🧠

Memory & Platform

The Xeon E3-1275 v5 uses the LGA1151 socket (PCIe 3.0), while the Xeon E5-1660 uses LGA2011 (PCIe 2.0) — making them incompatible on the same motherboard.