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Core i7-8700k vs i3-8100


Description
Both models i7-8700k and i3-8100 are based on Coffee Lake architecture.

Coffee Lake is the second refinement of Intel’s 14nm (Tri-Gate) technology. While it uses LGA1151 socket, it is incompatible with previous generations due to electrical changes in socket’s pins so these CPUs require Z370 chipset. This kind of generation introduced more cores in every range to compete with new AMD’s architecture. Coffee Lake uses DDR4 memory at 2400MHz for i3 and at 2666MHz for i5, i7 CPUs plus iGPU frequency has been increased 50MHz with respect to previous generation.

Using the multithread performance as a reference, the i7-8700k gets a score of 443.8 k points while the i3-8100 gets 205.4 k points.

Summarizing, the i7-8700k is 2.2 times faster than the i3-8100. To get a proper comparison between both models, take a look to the data shown below.

Specs
CPUID
906ea
906eb
Core
Coffee Lake-S
Coffee Lake-S
Architecture
Base frecuency
3.7 GHz
3.6 GHz
Boost frecuency
4.7 GHz
3.6 GHz
Socket
LGA 1151
LGA 1151
Cores/Threads
6/12
4/4
TDP
95 W
65 W
Cache L1 (d+i)
6x32+6x32 kB
4x32+4x32 kB
Cache L2
6x256 kB
4x256 kB
Cache L3
12288 kB
6144 kB
Date
October 2017
October 2017

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
i7-8700k
i3-8100
Test#1 (Integers)
4127
3704 (-10.26%)
Test#2 (FP)
16959
15303 (-9.76%)
Test#3 (Generic, ZIP)
5564
4810 (-13.55%)
Test#1 (Memory)
12845
5648 (-56.03%)
TOTAL
39495
29465 (-25.40%)

Multithread

i7-8700k

i3-8100
Test#1 (Integers)
24011
14280 (-40.53%)
Test#2 (FP)
108690
59006 (-45.71%)
Test#3 (Generic, ZIP)
36616
18550 (-49.34%)
Test#1 (Memory)
9327
3955 (-57.59%)
TOTAL
178644
95790 (-46.38%)

SSE3 optimized benchmark
The benchmark in mode I (SSE) is optimized for the use of SIMD instructions with 128 bits register and the SSE set up to version 3. Nearly every modern CPU has support for this mode.
Monothread
i7-8700k
i3-8100
Test#1 (Integers)
12920
13509 (4.56%)
Test#2 (FP)
20678
19411 (-6.13%)
Test#3 (Generic, ZIP)
5295
5066 (-4.32%)
Test#1 (Memory)
12587
7398 (-41.22%)
TOTAL
51480
45384 (-11.84%)

Multithread

i7-8700k

i3-8100
Test#1 (Integers)
94259
52705 (-44.08%)
Test#2 (FP)
152549
75624 (-50.43%)
Test#3 (Generic, ZIP)
39735
19695 (-50.43%)
Test#1 (Memory)
8527
4350 (-48.99%)
TOTAL
295071
152375 (-48.36%)

AVX optimized benchmark
The benchmark in mode II (AVX) is optimized to used 256 bits registers beside the first version of the Advanced Vector Extensions (AVX). The first AVX compatible CPU was released in 2011.
Monothread
i7-8700k
i3-8100
Test#1 (Integers)
16874
13519 (-19.88%)
Test#2 (FP)
26119
20623 (-21.04%)
Test#3 (Generic, ZIP)
6329
4973 (-21.43%)
Test#1 (Memory)
13708
7363 (-46.29%)
TOTAL
63030
46479 (-26.26%)

Multithread

i7-8700k

i3-8100
Test#1 (Integers)
105740
53186 (-49.70%)
Test#2 (FP)
180520
80814 (-55.23%)
Test#3 (Generic, ZIP)
44994
19314 (-57.07%)
Test#1 (Memory)
8512
3977 (-53.28%)
TOTAL
339766
157290 (-53.71%)

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
i7-8700k
i3-8100
Test#1 (Integers)
31204
24479 (-21.55%)
Test#2 (FP)
27821
21606 (-22.34%)
Test#3 (Generic, ZIP)
6568
5043 (-23.22%)
Test#1 (Memory)
15004
8221 (-45.21%)
TOTAL
80598
59348 (-26.37%)

Multithread

i7-8700k

i3-8100
Test#1 (Integers)
202422
96099 (-52.53%)
Test#2 (FP)
186332
84807 (-54.49%)
Test#3 (Generic, ZIP)
44958
19272 (-57.13%)
Test#1 (Memory)
10054
5173 (-48.55%)
TOTAL
443765
205351 (-53.73%)

Performance/W
i7-8700k
i3-8100
Test#1 (Integers)
2131 points/W
1478 points/W
Test#2 (FP)
1961 points/W
1305 points/W
Test#3 (Generic, ZIP)
473 points/W
296 points/W
Test#1 (Memory)
106 points/W
80 points/W
TOTAL
4671 points/W
3159 points/W

Performance/GHz
i7-8700k
i3-8100
Test#1 (Integers)
6639 points/GHz
6800 points/GHz
Test#2 (FP)
5919 points/GHz
6002 points/GHz
Test#3 (Generic, ZIP)
1397 points/GHz
1401 points/GHz
Test#1 (Memory)
3192 points/GHz
2284 points/GHz
TOTAL
17148 points/GHz
16486 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. 3.7.9