Why is the Core i5 5300u rated better than the i7 5600u?
That is normal for 3 main reasons:
the benchamrks score depends on the ram installed, whether it is in dual channel mode or not, so a core i5 with faster ram may perform faster.
heat sink and cooling, those processors are usually coupled with heat sink and fans that can only dissipate heat generated by 15 watt of power, which is the required by Intel, however, to achive higher turbo boost speeds, the processor needs to use more power than 15w, so it depends on the specific laptop and how much heat it can dissipate above the required 15 watts.
different manufacturers may limit the power draw when the processor tries to use more than 15 watts, to avoid possibly overheating the laptop.
The only thing you can do is to check that your laptop is cooling properly and not limited due to over heating.
If the processor is limited due to OEM, you can complain to them, in some cases they may relax limitation by a software update to the BIOS.
There is a small difference between them but i7 5600u is better because it has:
- Cache 4MB (vs 3MB)
- Processor Base Frequency 2.6 GHz (vs 2.3 GHz)
- Max Turbo Frequency 3.2 GHz (vs 2.7 GHz)
- Graphics Max Dynamic Frequency 950 MHz (vs 900 MHz)
But if I was buying I would go for the i5-5300U because it's a lot cheaper! (Recommended Customer Price $281.00 vs $393.00 for i7)
It's rated better because on tests i5 had better single core performance on both sites. On Cpubenchmark there is a huge difference in single core performance: i5(1644) vs i7(1248).
I really think it's the same cpu with different clock multiplier settings :D
And tests are there to be wrong! Just look at the Reasons to consider the Intel Core i7 5600U on Cpuboss.
There are more benchmarks and the i7 does beat the i5.
However, there still seems to be some weird performance benchmark scores flying out there. For example the Ars Technica review had some results where the gpu performance of the i7 was lower than a comparable i5's. He's got a request in with Lenovo to see why its occuring.
Here's the article: http://arstechnica.com/gadgets/2015/02/thinkpad-x1-carbon-review-a-fine-heir-to-the-thinkpad-name/2/