Mobile CPUs - How do I know if it's good enough?

Hardware Hub Laptops & Netbooks
1

My current laptop (crappy Acer netbook with an Atom N570) is too slow and old and not cutting it anymore as a daily driver for university (Office, web, light entertainment).

I’ve been looking around for a replacement but I don’t know which CPU to choose. With desktop CPUs it’s pretty straight forward but I’m kinda lost when it comes to mobile CPUs (how much does hyperthreading improve the performance, when do I profit from it, is an i3 in general better than a Pentium 3xxx or N3xxx, does it justify the price, etc ?).

Example:

Core i3-4005U - 2 cores, 4 threads / 1,7GHz

Pentium N3540 - 4 cores, 4 threads / 2,16GHz, 2,66GHz Turbo

Pentium 3558U - 4 cores, 4 threads / 1,7GHz

According to benchmarks, the N3540 performs worse than the 3558U and the i3. The numbers confuse me, I don’t know how to determine which will suit my needs and last for a couple of years (2-3y).

I’ve been looking at a few laptops with identical specs (15.6", 1366x768, 4GB RAM, 500GB-1TB HDD, 3 USB ports, 2y warranty), with the CPU being the exception. The prices are quite different, even when the brand is the same (i.e. Dell Inspiron 15 3000). Is the difference in price between a N3540 and a 3558U/i3-4005U justified or will the cheaper one be fine even in a few years?

If it was just the HDD and/or RAM I wouldn’t bother and just upgrade them in the future but that can’t be done with the CPU so I want to make sure I choose the best for me now.

2

The Pentium's aren't running the same cpu architecture as the core series. Intel has been doing this on the Atom and Pentium series where they take an older architecture and make the processing size smaller, which allows for great power efficiency, but gives sub-par performance. With laptops, my theory is that you should get the fastest part you can. I've got an atom powered tablet from only a couple years ago that can't even play hd video. The processor in that isn't super far off from those Pentium's, so I have to recommend getting at least a core M or core I part as a baseline in your laptop. I'll be buying a Core I5 5200U powered piece in a couple days my self, and from my research leading to my purchase it has become overwhelmingly obvious that anything below a Core I3 or Core M is just not worth the money and following headache.

3

Thanks for clearing that up.

I was hoping to spend less because of my limited budget as a student but I gladly spend a bit more if it saves me frustration in the future (like having to disassemble the whole laptop in order to upgrade the HDD/RAM; a maintenance flap is very important in that matter).

I hope I can get a certain laptop I have my eyes on (i5-5200U, 4GB RAM, 1TB HDD, 1080p IPS display for ~480€, that's a steal) but the chances are very low because it's from a local store that only has a very limited stock and it's been about a month since they had them for sale.
If I can't get one of them I have to settle for much less (i3-4005U, 4GB RAM, 500GB HDD, 1366x768 TN display for ~400-460€ (depending on the brand and model and I can't expand my budget any more).

But thanks for clearing that up. I would've been very frustrated if I had settled for a cheaper laptop that won't perform as good in a year or two (already had that experience with my netbook).

4

What makes this super confusing is Intel is using the same brand name across different architectures. Secondly, the specs are wrong for the Pentium 3558U. That's actually a dual-core part. In order of fastest to slowest

  • Core i3 4005u - 2c/4t - Haswell - With a beefed up iGPU and hyper-threading, this would be good for very light/casual gaming (think Sims, or Minecraft, maybe a few Real-Time Strategy games, etc), and would breeze through most everyday tasks. Good all around CPU

  • Pentium 3558U - 2c/2t - Haswell -because of same architecture and clock speeds, should before nearly identical to Core i3 in lightly threaded workloads, such as office work or basic web-browsing. This is meant to be a value oriented CPU for basic computing needs.

  • Pentium N3540 - 4c/4t - Silvermount - same architecture found in current Atom line-up. This one gives adequate performance in web-browsing and office work, it's primary purpose is very small form factors with minimal heat and power consumption - don't get this CPU in a 15" notebook unless it's in a chromebook. Best suited for 12" and under.

5

Sorry, I didn't realize I messed up the specs when I wrote them down from notebookcheck.net

6

Carrizo should only be like a month away man, I'd wait to see benchmarks if ya can.

Otherwise are you going to do any gaming on the laptop?

7

I'm not sure if I want to go the AMD route with laptops. My cousin has an A6-4455M in his laptop and regrets the purchase (running hot, no performance and battery only lasts ~1.5h).

Nothing demanding, mostly point'n'click adventures from a few years ago (Sam & Max, Runaway, Deponia, etc.).
The gaming performance is not important to me but I don't want to feel the aging of the technology and the need for a new laptop after only 1-2 years.

8

That's a pretty low end APU though, as far as the CPUs go the A10 5750M can compete pretty well against the i5 4200M at least according to CPUboss, if any of the carrizo rumors are true it should bring AMD back in the mobile market if they get a good device out.

9

I'm afraid the price will be the same. Especially after AMD stating that it doesn't want to be the cheaper solution anymore.
A laptop with an A10-5xxxM costs at least 500€, ones with an i5-4xxx only at ~385€. AMD might have the upper hand when it comes to APUs but I don't really need that much graphics power.

10

Might as well go for intel then. Overhere it's pretty close in price, but sometimes for around $500 you can get something refurbished with a 1080p screen and a GPU if it's got an AMD CPU in it.

11

Refurbished electronics are kinda rare here. Never seen anything else than the usual b-stock and refurbished (and still overpriced) Apple products.

I'm not really sure if I actually need a 1080p display. The difference in dpi between a 1024x600 10.1" display and a 1366x768 15.6" display (~117dpi vs. ~100dpi). It's not like I don't have a nice Dell U2414H on my desk, the laptop just needs to serve the purpose. That's why I feel like a better CPU will benefit me more, I just don't know which one gives me the best bang for the buck (especially if the difference in performance doesn't justify the premium).

12

If you can find something with a non U i5 in your price range you're probably set.

Or you always shoot for one of the cheap windows 8 tablets, they have like nice IPS displays and run fairly well anyways. just pair with a case and a keyboard and you're golden.

13

I'm not so sure if a tablet or one of those 2-in-1 laptop/tablet things would do the job for me. I kinda wanted a bigger screen this time and be able to upgrade the RAM/HDD.

Would an i3 be enough too?

14

Honestly, it sounds like a Pentium would be enough for you. In the mobile space, there is a big premium for small bits of performance because of the scarce power and heat budget. The only difference between a dual-core i3 and a dual-core i5 is a small amount of cache and Turbo Boost. In mobile space, Core i5 can be either hyper-threaded dual-cores, or non-hyper-threaded quad-cores. The quad-cores are without a doubt better than a dual cores, but most i5s of the lower voltage variety tend to be dual-cores.

There is so much inconsistency with the CPU names, and it really fluctuates based on segment
Bare (Celeron), Value (Pentium), Good (i3), Better (i5), and Best (i7).

But again, you have to keep the segment in mind: A regular Core i3 4100M (37W TDP) will be faster than a Core i7 4610Y (6W SDP/ 11.5W TDP) because the Core i3 is meant for a standard notebook, while that Core i7 is targeted at very small ultrabooks, netbooks, and tablets; a segment the standard mobile Core i3 can't perform in due to heat and power consumption being too high.

Anyway, the gist of what I'm saying is the Pentium (4xxxM, 5xxxM, - NOT the N3xxx) line should be fine for you, but if you can find a Core i3 or i5 model within $50 of a Pentium, go for it, otherwise keep your needs in mind and stick with a Pentium.

1 Like
15

That cleared things up for me pretty good. Thanks!

There's just one problem: there are no Pentium 4xxxM or 5xxxM. http://ark.intel.com/de/products/family/29862/Intel-Pentium-Processor#@Mobile N3xxx and 3xxxM/U/Y are the highest numbers.

16

And I stand corrected. And this is a prime example of the clusterfuck that is mobile chip naming. Typically the first digit indicates generation, so 4xxx series are 4th gen Core series, which holds true for Core series. Naturually, I had assumed 4th-gen Haswell Pentiums would start with a 4, but with the Pentium, Intel said fuck it and Haswell based Pentiums are 3xxx and Haswell based Celerons are 2xxx, not to be confused with 3xxx based Core i series based on Ivy Bridge, or the 2xxx based series based on Sandy Bridge.

Gist of it, Haswell Pentiums will work fine.

17

Ugh, this is so annoying. Who the hell can stay up to date and know all the differences in performance and value with this madness?

I think I'll be aiming for an i3-3xxxM if I can get one cheap and call it a day......my brain is fried.

18

I can verify on the i5 5200U. The experience is so much smoother than my A8-3520m. It might be because I have an SSD now though :P.

19

The ability of the intel to process stuff like streaming hd video and web browsing without really heating up or using a ton of power is second to none. The amount of performance in that 15 watt thermal threshold is out standing.

20

@thecaveman @jerm1027

Tomorrow I'll see if I can get a Medion Akoya E6416 (MD99544) which would be awesome (i5-5200U, 4GB RAM, 1TB HGST HDD, 1080p, 3y warranty for ~480€) but there's a very big chance they don't have them in stock anymore.

Alternative would be a Dell Inspiron 15 3000 (Pentium 3558U, 4GB RAM, 500GB HDD, 768p, 2y warranty, easy access maintenance cover for ~360€) or the i3-4005U version for ~460€. Just not sure if the i3 is worth paying 100€ more.