Back to the I5 vs I7 debate. In this post I’ll test the I5-4200M vs the I7-4700MQ inside a W650SJ Clevo machine (Eurocom Electra 2.0 in this case). It is very compelling to get an I7 with twice the cores over the I5 for like 10-20% premium in some laptop and it is also known that some games in some cases can make use of the I7 capabilities and specifically, the 8 logical cores compared to the 4 cored of the mobile I5.
I5-4200M and I7-4700MQ basic specs:
|CPU||# of cores / thread||Clock speed||GPU||TDP|
|I5-4200M, 22nm||2 / 4||2.5 – 3.1 GHZ (Turbo)||HD4600. 0.4-1.15GHZ||37W|
|I7-4700MQ / I7-4700HQ, 22nm||4 / 8||2.4 – 3.4 GHZ (Turbo)||HD4600. 0.4-1.15GHZ||47W|
Most benchmarks done in this field – or at least those that are quoted – are made with some monster GPUs, which eliminate to some high degree the GPU bottleneck. The result is that the CPU power is more pronounced in these cases. However, the case with a midrange GPU power is different. In most games, played with reasonable graphics settings on current $800-$1200 gaming laptop, you’d probably hit the GPU ceiling well before the CPU power can shine.
I’ve already posted a comparison between the Toshiba X70 with an I7-4700MQ and GTX 770M and the Y510p with GT 750M SLI and I5-4200M. If there was a significant advantage for an I7 for such configuration, it should show. The test was built around the BF4 campaign and multiplayer modes. The result was that an I5 would work a lot more, but generally for such a level of GPU, performance was about the same. The GTX 770M roughly equals the GT 750M SLI and GTX 860M in gaming performance. The GTX 850M is like the previous generation GTX 765M or GT 650M SLI. So I would expect to have around the same results.
Measuring performance and temperatures
System: Clevo W650SJ, equipped with an I5-4200M (system 1) / I7-4700MQ (system 2) and a GTX 850M, 1x8GB DDR3 and 500GB 7200RPM HDD. You can read the full review here.
The Clevo W650SJ uses the same fan for both the CPU and GPU so the temperatures of both of them are coupled and a CPU which is a bit hotter might overload the cooling system under full load of the GPU and CPU.
- Idle: Temperatures while Idling for few minutes
- GPU only : Temperatures under Furmark load
- CPU only : Temperatures under Prime95 load (CPU only test)
- CPU + GPU load : Temperatures under Prime95 + Furmark load
Gaming performance test:
In test (all 1080p):
- Battlefield 4: ‘high’ settings
- Titanfall : highest settings, MSAAx4. Minimal FPS.
- Total War II : ‘Ultra’ settings
- Borderlands 2 : highest settings, Physx on ‘high’
- Crysis 3 : ‘High’ settings, SMAAx2
- World of Tanks : ‘High’ settings, FXAA on
- Bioshock Infinite : Highest settings, no AO enabled in Nvidia Control Center.
I’ll add now a series of benchmarks I’ve done with the W650SJ using an I5-4200M and an I7-4700MQ:
GPU temperatures are not a lot different – under full load of the CPU and GPU, the CPU does get hotter. Note that there are some differences in ambient temperature, so small differences say nothing actually.
However, the CPU front is a different thing. The CPU would get 15C hotter under full CPU+GPU load and 12C under full CPU load. This is a significant difference in favor of the I5-4200M and also remember that the I5-4200M was not throttled, it was set on 3.GHZ-3.1GHZ while as the I7 clocks was set on 2.6-2.7GHZ.
It is quite obvious that the I7 is a lot hotter which is no surprise. The laptop in test is the Clevo W650SJ (Eurocom Electra 2.0) which uses the same fan for both the GPU and CPU. That’s true that in some other laptops with two separated fans for the CPU and GPU the results might be different, but they usually cost more and will come with a GTX 870M and up.
It’s quite obvious that the I7 has no real advantage in FPSs, even in Crysis 3 where is it known to use the abilities of an I7. This is the case with midrange GPU level of a GTX 860M or GTX 850M – the GPU bottlenecks way before t he small advantage of the I7 kicks in.
I haven’t tested the difference in BF4 multiplayer in this one, but according to my previous tests, though the CPU does make more effort, the difference in gaming performance is not significant. I’m not saying that an I7 won’t have benefit with future 3D Engines, but currently, for such a GPU level, the difference is minimal and might have some benefit only in extreme cases.
Bottom line, if there is a big premium for an I7 laptop, I would seriously suggest considering the I5 version (like in the Y510p I5 vs I7 case) as the I5 version not only delivers around the same gaming performance, but also produces considerably less heat. In laptops like the Clevo W650SJ with a single fan for both the GPU and CPU, this is significant issue. The same goes for the Lenovo Y510p, Clevo W230SS (GTX 860M), Asus N550JK (no I5 version though) and more.