i5 2520M vs 2540M on a Thinkpad T420

Hello there, I am going to get a T420 soon. I picked out this one because it definitely has the best value and because of a few other reasons. Anyways, I am still considered a University student until August and I need a new laptop because the one I have is about done for. I decided on everything I wanted except the processor.
My options are:

Intel Core i5-2520M Processor (2.50GHz, 3MB L3)
Intel Core i5-2540M Processor (2.60GHz, 3MB L3) [add $45]
Intel Core i7-2620M Processor (2.70GHz, 4MB L3) [add 171]

I do figure the upgrade from the i5 2520M to the i5 2540M for $45.00 USD justifiable.
I can't decide whether upgrading the i5 2540M to 2620M for an additional $126 USD is justifiable.

I do plan to do a little gaming on the laptop when I am traveling, but I have a monster gaming destop at home that I do a lot of gaming on, so I don’t plan on doing heaving gaming on it. Movies will be played on this a lot. I did choose to upgrade from the integrated graphics. I can tell the difference between integrated graphics and dedicated graphics when watching movies or looking at pictures.

I also have a 160GB Intel SSD I got for my current laptop 2 months ago and I plan to install it on the new laptop and use the 500GB as an external hard drive to hold extra movies and music.

Here is my specs list I have chosen (I cut and pasted off from the Lenovo shopping cart)

Processor Intel Core i5-2540M Processor (2.60GHz, 3MB L3)
Operating system Genuine Windows 7 Professional 64
Display type 14.0 HD+ (1600 x 900) LED Backlit Anti-Glare Display, Mobile Broadband Ready
System graphics NVIDIA NVS 4200M Graphics with Optimus Technology, 1GB DDR3 Memory
Total memory 4 GB PC3-10600 DDR3 SDRAM 1333MHz SODIMM Memory (2 DIMM)
Camera 720p HD Camera
Hard drive 500 GB Hard Disk Drive, 7200rpm (I will be changing this out to a 160GB SSD and using the 500GB as an external drive)
Optical device DVD recordable multiburner
System expansion slots Express Card Slot & 4 in 1 Card Reader
Battery 9 cell Li-Ion Battery - 55++
Power cord Country Pack North America with Line cord & 90W AC adapter
Bluetooth Bluetooth 3.0
PCI adapter IEEE 1394a port
Integrated WiFi wireless LAN adapters Intel Centrino Ultimate-N 6300 (3x3 AGN)
Integrated mobile broadband Integrated Mobile Broadband - Upgradable

I plan on also purchasing the Lenovo 90W Ultraslim AC/DC Combo Adapter and a sleeve case.

With my student discounts and 10% off, it all comes out to just under $1200.00 USD

But my question out of all of this is will the upgrade the i5 2540M to 2620M for an additional $126 USD is justifiable. It’s an increase by 100MHz in both clock speed and turbo boost and an increases cache worth it or am I wasting my money.

 

The difference between the i5 2520 and the i7 2620 is 200MHz which is measurable in benchmarks but would barely be noticeable in everyday usage.

See the notebookcheck mobile CPU benchmark list for results with the different CPUs (hover over the scores to see the range of numbers).

In theory, the faster CPUs are more power-efficient since they all have to operate within the same thermal rating but, in reality, the differences between CPUs of the same model are enough to have some impact on the idle power consumption. However, they are all more power-efficient than the Arrandale CPUs.

Before you commit to Optimus, have you checked out the performance of the Intel 3000 HD GPU? See here for a range of benchmark results. I'm surprised that you think that it falls short on video playback.

John

 

I know most people on here will tell you to decide against going from the 2540m to the 2620m on the basis that in real world application you won't really see the difference, ever.

In my opinion save the $126 and stick with the 2620M, unless you're doing some virtualization stuff or whatever you won't need the 2620M

Edit: John beat me to it, haha.

 

I should say I can tell the difference when it comes to color clarity and depth, not nessisarly performance

 

I'm going to start out here by respectfully disagreeing. 100MHz in clock-speed (with no extra features besides that) for $45.00.

That's 45 cents per 1MHz increase. I find that a lot of money for a gain in performance so negligible that it's barely quantifiable on most benchmarks. So I'm going to start off by saying if you can't justify the i7, you definitely shouldn't justify $45 for the 2540M.

Now, let's compare the 2520M with the 2620M.

Compare Intel® Products

You get an extra 1MB of cache. You get an extra 200MHz of clock-speed. Those are the two features you get for $171. You're paying 85 cents per 1MHz increase, plus 1MB more of cache. I'd have an even harder time justifying that kind of cost increase.

For that $171, you can just about buy yourself an 80GB Intel mSATA SSD from NewEgg that will do far more for the performance of your new T420 than either processor upgrade will. You can use it as a boot drive and keep your 500GB hard drive internal; I'm doing this and it works beautifully. If that's not what you want, you can buy an 8GB RAM kit aftermarket for $80, which IMO is still a better route than $171 for a modest increase in processor performance.

I was able to easily justify an upgrade from Core i5-2410M to core i5-2520M due to additional processor features that I'll actually make use of in my case. I saw little benefit in going beyond that --and my 2520M easily beats my previous Core 2 Duo T9600 which was a very near top-end processor itself at one point.

 

Totally agree with LoneWolf15.
Invest yourself in 1) an mSATA soda creek Intel SSD or 2) SSD with ultrabay adapter. The ultrabay + SSD was the single best upgrade I have ever made. But SSD + ultrabay will cost you just about much as the mSATA, I guess mSATA could be a better option considering you will have an optical drive open.
Now I can't imagine using spinning hdd's for my OS.

 

+1 for the SSD and going with the 2520. the integrated graphics are quite powerful, but if you have the budget the optimus option is nice to have

 

ok. I will definitly NOT go with the 2620M.

I have a budget I am shooting for around $1300

 

well then it sounds even with a small SSD you'll still be within budget if you go for the 2520

 

I have an intel 160GB SSD I just installed in my 4 year old Dell XPS laptop. I am going to install it in the T420, so budget wise, it has no effect. BUT I was going to take the hard drive out of the T420 and utilize it as an external hard drive.

and I mixed up the title of the thread. It should have read "2540M vs. 2620M"

 

think a lot of the responses here favoured the 2520M actually, over then 2540 anyway, and judging by the spec you posted, 45 bucks more to upgrade from the 2520 to the 2540 is not worth it. so i guess you can save an extra 45 bucks that way. unless your lenovo rep gives you a good discount with the 2540 making it just a bit more expensive

 

ok. Here is what I am going to do. I'll order the 2520M, unless I can "convince" the sales rep to give the the upgrade for the 2540M for 20 bucks maybe.

 

sounds like a plan