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Core i5-8400 vs i7-6700K


Description
The i5-8400 is based on Coffee Lake architecture while the i7-6700K is based on Skylake.

Using the multithread performance as a reference, the i5-8400 gets a score of 289.6 k points while the i7-6700K gets 254.6 k points.

Summarizing, the i5-8400 is 1.1 times faster than the i7-6700K . To get a proper comparison between both models, take a look to the data shown below.

Specs
CPUID
906ea
506e3
Core
Coffee Lake-S
Skylake-S
Architecture
Base frecuency
2.8 GHz
4 GHz
Boost frecuency
4 GHz
4.2 GHz
Socket
LGA 1151
LGA 1151
Cores/Threads
6/6
4/8
TDP
65 W
95 W
Cache L1 (d+i)
6x32+6x32 kB
4x32+4x32 kB
Cache L2
6x256 kB
256 kB
Cache L3
9216 kB
8192 kB
Date
September 2017
May 2015
Mean monothread perf.
64.98k points
63.22k points
Mean multithread perf.
289.61k points
254.56k points

Non-optimized benchmark
The benchmark in Mode 0 (FPU) measures cpu performance with non-optimized software. It uses the basic µinstructions from the i386 architecture with the i387 floating point unit. This mode is compatible with all CPUs so it's practical to compare very different CPUs
Monothread
i5-8400
i7-6700K
Test#1 (Integers)
4.08k
4.07k (x1)
Test#2 (FP)
14.96k
16.62k (x1.11)
Test#3 (Generic, ZIP)
4.98k
5.23k (x1.05)
Test#1 (Memory)
10.29k
6.28k (x0.61)
TOTAL
34.31k
32.2k (x0.94)

Multithread

i5-8400

i7-6700K
Test#1 (Integers)
21.54k
16.37k (x0.76)
Test#2 (FP)
85.13k
77.34k (x0.91)
Test#3 (Generic, ZIP)
28.24k
25.65k (x0.91)
Test#1 (Memory)
4.08k
10.21k (x2.5)
TOTAL
139k
129.57k (x0.93)

AVX2 optimized benchmark
The benchmark in mode III (AVX2), like AVX1, is optimized to used 256 bits registers beside the second version of the Advanced Vector Extensions (AVX). The first AVX2 compatible CPU was released in 2013.
Monothread
i5-8400
i7-6700K
Test#1 (Integers)
26.5k
25.78k (x0.97)
Test#2 (FP)
23.11k
23.08k (x1)
Test#3 (Generic, ZIP)
5.2k
5.32k (x1.02)
Test#1 (Memory)
10.16k
9.03k (x0.89)
TOTAL
64.98k
63.22k (x0.97)

Multithread

i5-8400

i7-6700K
Test#1 (Integers)
135.08k
112.83k (x0.84)
Test#2 (FP)
121.49k
106.86k (x0.88)
Test#3 (Generic, ZIP)
27.53k
25.76k (x0.94)
Test#1 (Memory)
5.5k
9.12k (x1.66)
TOTAL
289.61k
254.56k (x0.88)

Performance/W
i5-8400
i7-6700K
Test#1 (Integers)
2078 points/W
1188 points/W
Test#2 (FP)
1869 points/W
1125 points/W
Test#3 (Generic, ZIP)
424 points/W
271 points/W
Test#1 (Memory)
85 points/W
96 points/W
TOTAL
4455 points/W
2680 points/W

Performance/GHz
i5-8400
i7-6700K
Test#1 (Integers)
6626 points/GHz
6139 points/GHz
Test#2 (FP)
5778 points/GHz
5495 points/GHz
Test#3 (Generic, ZIP)
1300 points/GHz
1268 points/GHz
Test#1 (Memory)
2541 points/GHz
2150 points/GHz
TOTAL
16245 points/GHz
15052 points/GHz

Monothread performance graph
Monothread performance graphics gives the performance vs time. They are useful to measure the time it takes to the CPU to reach the maximum performance.

Usually, CPU's performance will be steady during these tests but if it has a slow frequency strategy, the first samples will show a lower score.


Test#1 (Integers) [points vs time]

grafica bm.hardlimit.com


Test#2 (FP) [points vs time]

grafica bm.hardlimit.com


Test#3 (Generic, ZIP) [points vs time]

grafica bm.hardlimit.com


Test#1 (Memory) [points vs time]

grafica bm.hardlimit.com

Multithread performance graph
Multithread graphs measure the performance against a heavy load during certain time.

If CPU's TDP doesn't limit the frequency and the machine is properly cooled, performance should remain steady vs time. Otherwise, the performance score will oscillate or decrease over time.


Test#1 (Integers) [points vs time]

grafica bm.hardlimit.com


Test#2 (FP) [points vs time]

grafica bm.hardlimit.com


Test#3 (Generic, ZIP) [points vs time]

grafica bm.hardlimit.com


Test#1 (Memory) [points vs time]

grafica bm.hardlimit.com

Hardlimit Benchmark Central - Ver. 3.11.4