Intel Core i7-6700T vs Intel Xeon E3-1575M v5 Comparison

The Intel Core i7-6700T and Intel Xeon E3-1575M v5 are both 14nm Skylake parts with identical core counts, but they are engineered for entirely different worlds. The benchmark data is unambiguous: the Xeon E3-1575M v5 wins every single head-to-head test, posting a 10% advantage in multi-core workloads and roughly a 9-10% lead in single-core tests. However, the i7-6700T is not without its own distinct purpose; its 35W TDP and desktop socket make it the logical choice for low-power compact builds, while the Xeon’s 45W TDP and server-focused feature set target professional workstations. The data shows a clear performance hierarchy, but the correct pick depends entirely on whether raw speed or platform flexibility matters more for your specific use case.

Where Each One Wins

The Xeon E3-1575M v5 wins every benchmark in this comparison, making the performance split a clean sweep. In Cinebench R15 multi-core, the Xeon scores 665 against the i7-6700T’s 599, a 9.9% gap. That lead extends to Cinebench R20 multi-core (2774 vs 2496) and R23 multi-core (6607 vs 5943), both exactly 10% advantages. Single-core results mirror this pattern: the Xeon leads by 9.7% in R15 (93 vs 84) and by 10% in both R20 (391 vs 352) and R23 (932 vs 839). If your workload is threaded rendering, video encoding, or any CPU-bound professional task, the Xeon is the undisputed winner.

The i7-6700T’s win is not in raw performance but in efficiency and platform compatibility. It carries a 35W TDP versus the Xeon’s 45W, making it the better fit for silent or thermally constrained systems where every watt counts. It uses the Intel Socket 1151, a mainstream desktop platform, whereas the Xeon uses the proprietary Intel BGA 1440 socket, which is soldered and not user-upgradeable. The i7-6700T is also a desktop-market part with HD Graphics 530, while the Xeon targets the server/workstation segment with Iris Pro Graphics P580. For someone building a small form-factor PC or upgrading an existing LGA 1151 motherboard, the i7-6700T is the pragmatic choice—it sacrifices roughly 10% performance to fit into a far more common and lower-power envelope.

FAQ

Q: Which CPU is faster in multi-core benchmarks?

A: The Intel Xeon E3-1575M v5 wins every multi-core test. It scores 665 vs 599 in Cinebench R15, 2774 vs 2496 in R20, and 6607 vs 5943 in R23—each a 10% advantage over the i7-6700T.

Q: Is the single-core performance difference significant?

A: Yes, and it is consistent. The Xeon leads by 9.7% in Cinebench R15 (93 vs 84) and by exactly 10% in both R20 (391 vs 352) and R23 (932 vs 839). This translates to snappier response in lightly-threaded applications.

Q: Do both CPUs support ECC memory?

A: No. The Xeon E3-1575M v5 supports ECC memory, while the i7-6700T does not. This is a critical differentiator for workstation reliability and data integrity.

Q: What are the TDP differences and why do they matter?

A: The i7-6700T has a 35W TDP, while the Xeon E3-1575M v5 has a 45W TDP. The lower TDP of the i7-6700T means less heat generation and lower cooling requirements, making it suitable for compact or passively cooled systems.

Q: Which CPU has a higher boost clock?

A: The Xeon E3-1575M v5 boosts to 3.90 GHz, while the i7-6700T boosts to 3.60 GHz. The Xeon also has a higher base clock at 3.00 GHz versus 2.80 GHz.

Q: How do their average benchmark scores compare?

A: The two are nearly identical on average. The i7-6700T has an average benchmark score of 1918, and the Xeon E3-1575M v5 scores 1910. Both sit at the 43rd percentile of all CPUs, meaning they perform identically against the broader market despite the Xeon’s head-to-head sweep.

Head-to-Head Benchmarks

The head-to-head data shows a perfect 6-0 victory for the Xeon E3-1575M v5, with every delta falling between -9.7% and -10%. The largest single gap is in Cinebench R15 multi-core, where the Xeon’s 665 score beats the i7-6700T’s 599 by 9.9%. The single-core R15 test shows the smallest margin at 9.7% (93 vs 84). All four other tests—R20 multi-core, R20 single-core, R23 multi-core, and R23 single-core—show an identical 10% delta.

These numbers tell a consistent story: the Xeon is uniformly 10% faster across both single and multi-threaded workloads. This uniformity suggests the performance gap is driven by clock speed rather than architectural efficiency. The Xeon’s higher base clock (3.00 GHz vs 2.80 GHz) and boost clock (3.90 GHz vs 3.60 GHz) account for the entire difference. The i7-6700T is not slower due to a weaker design; it is simply clocked lower to achieve its 35W TDP target, trading 10% of performance for a 10W reduction in power draw.

The average benchmark scores reinforce this: the i7-6700T averages 1918, and the Xeon averages 1910, a difference of only 0.4%. Their nearest rivals confirm they are in the same performance class. The i7-6700T sits within 0.4% of the AMD Ryzen 3 7320U (1916) and the Intel Xeon E-2314 (1911), while the Xeon is within 0.1% of the AMD Ryzen 5 PRO 2400GE (1910) and the Intel Xeon E3-1285 v4 (1908). The head-to-head tests expose a 10% gap that the broader average scores obscure, because the average pulls in results from different benchmark suites where the two are more comparable.

Specification Differences

The core and thread counts are identical: both have 4 cores and 8 threads. The L1 cache is the same at 64 KB per core, as is L2 at 256 KB per core, and L3 at 8 MB shared. Memory support is also identical: both use DDR3 and DDR4 in a dual-channel configuration with a 34.1 GB/s memory bandwidth, and both use PCIe Gen 3 with 16 lanes from the CPU.

The differences are concentrated in clock speeds, power, and platform. The i7-6700T has a base clock of 2.80 GHz and a boost of 3.60 GHz, while the Xeon runs at 3.00 GHz base and 3.90 GHz boost. The i7-6700T has a 35W TDP; the Xeon uses 45W. The i7-6700T uses Intel Socket 1151, while the Xeon uses Intel BGA 1440. The i7-6700T does not support ECC memory; the Xeon does. The i7-6700T has HD Graphics 530 integrated graphics; the Xeon has Iris Pro Graphics P580. The i7-6700T is a desktop part, and the Xeon is a server/workstation part. The i7-6700T launched on 2015-08-31 with a launch MSRP of $303, while the Xeon launched on 2016-01-23 with a launch MSRP of $1207. Neither has an unlocked multiplier.

Architecture Differences

Both CPUs are built on Intel’s 14nm process and use the Skylake architecture. The i7-6700T is codenamed simply “Skylake” and belongs to the Core i7 (Skylake) generation, while the Xeon is codenamed “Skylake-H” and is part of the Xeon E3 (Skylake-H) generation. The Xeon has published transistor count and die size figures: 2,300 million transistors and a 171 mm² die. No such figures are listed for the i7-6700T.

The memory controllers are identical, and both support the same dual-channel DDR3/DDR4 configuration. The critical architectural split is in the integrated graphics and ECC support. The Xeon’s Iris Pro Graphics P580 is a more advanced GPU solution than the i7-6700T’s HD Graphics 530, reflecting its workstation positioning. The Xeon’s ECC memory support is a structural addition for error correction in professional environments, while the i7-6700T’s lack of ECC makes it unsuitable for mission-critical data integrity tasks. The Xeon’s higher TDP of 45W versus 35W for the i7-6700T is directly tied to its higher clock speeds and more capable integrated graphics. The socket difference is the most practical architectural distinction: LGA 1151 is a replaceable desktop socket, while BGA 1440 is a soldered mobile-style package, meaning the Xeon is permanently attached to its motherboard.

The Verdict

The data leads to a straightforward conclusion: choose the Intel Xeon E3-1575M v5 if you need maximum performance and ECC memory support in a workstation scenario. It wins every benchmark by a uniform 10%, from Cinebench R15 multi-core (665 vs 599) to R23 single-core (932 vs 839). Its higher base and boost clocks (3.00/3.90 GHz vs 2.80/3.60 GHz) deliver that advantage without any architectural compromise. The Xeon’s ECC memory support and Iris Pro Graphics P580 make it the only option here for error-correcting memory and more demanding integrated graphics tasks. Its server/workstation market segment and BGA 1440 socket are acceptable trade-offs if you are building a dedicated professional machine.

Choose the Intel Core i7-6700T if your priority is low power consumption and desktop platform flexibility. Its 35W TDP is 10W lower than the Xeon’s, making it ideal for compact, quiet, or thermally limited builds. The LGA 1151 socket means it can be installed in a wide range of standard desktop motherboards, offering upgrade and replacement options that the soldered BGA 1440 Xeon cannot. The i7-6700T is only 10% slower in every test, which is a modest penalty for a significant reduction in power draw and a vastly more accessible platform. Its launch MSRP of $303 also reflects a consumer-market positioning, though both parts are end-of-life. If you are upgrading an existing LGA 1151 system or building a low-power desktop, the i7-6700T is the sensible pick; if you are assembling a new workstation and want the fastest possible Skylake performance with ECC, the Xeon E3-1575M v5 is the clear winner.