Haswell laptop CPU

[rds1220]

I was looking at getting a new laptop and I was going to go with an Intel based laptop but I have some concerns. I was looking at laptops with Haswell CPUs and literally all the I3 and I5s are ultra low power "U" type processors. They are only running at 1.5 to 1.9 GHZ. This is a good bit slower than the Sandy Bridge CPU I have now. Does Intel not make normal non ultra low power mobile CPUs anymore? I am concerned about performance as from my experience ultra low power CPUs tend to be slow junk and as the the computer gets older they become unbearable.

 

[Archaic59]

Lower power means longer battery life. Here's a way to help you judge mobile cpu performance:

http://www.cpubenchmark.net/laptop.html

 

[rockie_]

Yes , i5 4200M, i5 4200H , i7 4710HQ ,

http://www.cpubenchmark.net/cpu_list.php

if the laptop is for gaming , get with Geforce 840M at least
like
http://www.newegg.com/Product/Product.aspx?Item=N82E16834314535&cm_re=840m-_-34-314-535-_-Product

http://www.notebookcheck.net/Mobile-Graphics-Cards-Benchmark-List.844.0.html

 

[Solandri]

I was looking at laptops with Haswell CPUs and literally all the I3 and I5s are ultra low power "U" type processors. They are only running at 1.5 to 1.9 GHZ. This is a good bit slower than the Sandy Bridge CPU I have now.

The low-power i3 CPUs tend to be junk. But the low-power i5s have Turbo Boost. They will overclock by nearly 1 GHz under load.

http://en.wikipedia.org/wiki/List_of_Intel_Core_i5_microprocessors#.22Haswell-ULT.22_.28SiP.2C_dual-core.2C_22_nm.29

e.g. The i5-4200U has a base 1.6 GHz, but Turbo is listed as 7/10. This means when using two cores it will overclock by 700 MHz (bumping it up to 2.3 GHz). When using a single core it will automatically overclock by 1000 MHz (bumping it up to 2.6 GHz). As long as it doesn't overheat.

The M processors have about a 1 GHz higher base frequency, but Turbo Boost by only about 600 MHz. e.g. The i5-4200M has a base 2.5 GHz, but Turbo is 5/6. So it will overclock to 3 GHz on 2 cores, 3.1 GHz on 1 core.

So if you looked at just the base clock speed, the 4200M would appear to be 2.5/1.6 = 56% faster. But in reality the 4200M is 3/2.3 = 30% faster on two cores, and only 3.1/2.6 = 19% faster on a single core. Personally I don't think that small a performance gain is worth the jump from a 15 W TDP to 37 W TDP.

For most of the Sandy Bridge i5 M processors, the Turbo Boost is only 300 MHz / 600 MHz. So the speed difference from a Haswell i5 U is even smaller. Basically the M processors are the ones which failed to run at low voltages, so Intel binned them as higher power components. They need higher voltages to run (thus using more power), and Intel cranked up their clock speed to give people a reason to buy them. That's why the U processors can Turbo Boost to near M processor speeds while still using much less power.

The mobile i3s don't have Turbo Boost, so yeah their sucky base clock speed is the best you'll get.

 

[jaguarskx]

Laptops with Broadwell CPUs are starting to hit the market so you might want to wait a little while for more of these laptops to come out if you can afford to wait. Assuming the same clock speed Broadwell CPUs are marginally more powerful than Haswell CPUs. The integrated graphics core is also more powerful if that matters to you; about 20% - 35% depending on the Intel HD graphics core. They also offer longer battery life due to a little less power consumption.

As mentioned above, Core i5 and Core i7 CPU have two speeds; the base clock speed and the Turbo Boost speed. Core i3 CPUs only have the base clock speed. The Turbo Boost speed is the max clock speed assuming only one core is being used; if both cores are used then it is usually about 300MHz slower than the max Turbo Boost speed.

Laptops generally comes with the less expensive Core i3 or Core i5 "U" model CPUs which generally have low clock speeds but makes the laptops fairly inexpensive. However, different models can come with more powerful CPUs, but that adds costs. An example of a laptop using the newer Broadwell Core i5 CPU is the 15.6" ThinkPad E550 laptop from Lenovo.


http://shop.lenovo.com/us/en/laptops/thinkpad/e-series/e550/


In this example, the ThinkPad E550 has a starting price of $579 and only comes with a Haswell generation core i3-4005u @ 1.7GHz. However, the Broadwell generation Core i3-5005u @ 2.0GHz is a free upgrade; all you need to do is select it. There is also an option to select the Core i5-5200u for $100 which has a base clock speed of 2.2GHz and a max Turbo Boost speed of 2.7GHz. Last is an option for the Core i7-5550u CPU for $260 which has a base clock speed of 2.0GHz, but can max out at 3.0GHz. Performance is a premium. Selecting the Core i7-5550u automatically adds a discrete graphics card to the laptop; the Radeon R7 (M260 ???); and tacks on an additional $89 for that graphics card.

Therefore, it is possible to get a more powerful CPU in laptop as long as you are will to pay a premium for it.