i5 2.6 vs i7 2.7 - Is it worth upgrading to i7 for the price?

I'm debating an i5 - 2540 (2.6 ghz) vs an i7 - 2620 (2.7ghz). Can anyone tell me if there is a significant improvement in performance if I go with an i7? Is it worth the $140 price jump for a slightly bigger cache (4mb) and a 0.1 ghz improvement? Right now Lenovo has the i5-2.6 upgrade at $50 and the i7-2.7 at $190. I'm going to use it mostly for development, possibly some photoshop and maybe the occasional video (no editing of course).

 

Which laptop model? I went with the i7 on the X220 to get the USB 3.0 as it's only available with the i7.

 

T420 and maybe even the E420.

 

Not worth it for those models. You'll notice virtually no benefit in any real life situation.

 

It's worth mentioning that according to AnandTech in some situations i7 with HT enabled can be slower than an i5 with the same clock speed.

I personally wouldn't bother with paying extra, unless it's for other benefits, like USB 3.0 or true need for HT.


M.

 

Cool, thanks guys. I thought with the i7, it might improve the graphics performance for the added cache.

Btw, on which model would this difference be significant?

 

It's not even worth it to get the 2540M. Get the 2520M for the best value.

 

As stated in real world use, you will not see the different. It will make a minuscule difference when you render or synthetic benchmarks.

The i7 will have higher turbo frequencies, but other than that not really significant.

 

This.

The 2520M has all the features a Sandy Bridge processor can have --and it's only 100MHz slower at standard clock speed or at peak turbo. Fifty bucks more to get the 2540M really doesn't justify it for the extra 100MHz you're getting.

If you want to spend fifty bucks, spend it on aftermarket RAM, or towards an 80GB mSATA SSD, upgrades that you'll actually see a tangible benefit from.

 

You can compare the performance of the different CPUs using the notebookcheck CPU benchmark list. Faster CPUs will only bring noticeable benefits if you run programs which load the CPU for substantial periods of time. As already suggested, investing in an SSD will boost the overall responsive of the computer.

John

 

That I'd take with a grain of salt. There's no rational reason why it's perform worse, why I'd sooner attribute that to imperfect measurements. On the other hand, I fully agree with all who say the potential increase in performance is likely to be minuscule.

Hardly there either. The max turbo freq is also just 100MHz above the 2540 (and another 100 above the 2520).

+1 on that.

 

No, the i5-2520M's all you really need for a T420.
You could get the 2540 but the money's better spent elsewhere- you can get a 40 GB mSATA SSD for 80 bucks anyways.

If you have to have an i7, go for the W520 since that's cheaper, it's quad-core (2720QM), and it's got a graphics card quite a bit more powerful than that NVS 4200M.

(Also, you don't get USB with a T420 and i7- that's the X220)

 

Get i7. If you are spending that much money get the best even if its only minimal. You get i7 for bragging rights and xtra bonus usb 3.0 for the x220.

 

I believe that's the reason why I want an i7; although battery life and low heat should trump whatever negligible speed I would gain from the i7.

 

Be careful with the W520 i7 dual-core model, unlike the quad-core model it doesn't include the 1600x900 screen as minimum. You'll want to upgrade it from the 1366x768 screen to the 1600x900 screen to justify it for Photoshop use as a 15.6" laptop.

But no you won't get a noticeable gain in performance with the i7 unless you go for a quad-core i7 (which the T420 does not have).

By the way, the T420 is probably not the best choice of a computer to run photoshop, due to the numerous complaints about screen quality (low contrast, terrible viewing angles). You'll probably be better off with a T520 or W520 with either the 1600x900 or preferrably 1920x1080 95%-gamut screen. (Nothing special about the 1600x900 screen except for the fact that it's better than 1366x768, but the 1920x1080 has excellent color reproduction)

 

hey guys,

I've got a similar problem. just received my i5 T420 with 2520, 2 GB (upgraded to 6GB with a 4GB module I had lying around), 250GB 5400RPM, no fingerprint reader, etc. for $746 (before tax). it's also worth mentioning I got the LG HD+ panel, which apparently is better than the AUO one, and that the laptop is near-silent.

two days after I received it, I created a quote for an i7 T420 with 2620, 4 GB, 320GB 7200RPM, w/ fingerprint reader for $899 (before tax) - everything else is the same. I'm looking at a $150+tax=$165 price difference, and just wondering if it makes sense for me to return the i5 one and get the i7 one (assuming I won't have to pay the restocking fee, that is).

I need my laptop mostly for CPU-intensive programs like Matlab, GAMS, Stata and R. I must admit I'm not overly impressed with the i5 I got as it seems a bit sluggish (I haven't yet performed a clean install though!). I suppose i7 would fare better in this respect, especially if coupled with a faster drive (and 2 more GBs of RAM OOTB). However, there's also the HD+ panel lottery (I might get the AUO panel) and I've seen people complain about the noise the 7200RPM drives make... (also not sure how much an expensive SSD would help with computational stuff that Matlab does, so that's probably not an option for now to speed things up).

I should've said this before: I'm not interested in the resale value of my laptop, as I keep all my laptops (still using my 2003 R40, e.g.) and never sell them.

thanks for your feedback

 

replace your HDD with an SSD and you won't care about which processor is slightly faster than another. (smile)

 

Hm, for Matlab I need raw computing power, I seriously doubt an SSD will make a huge difference there...

 

Excellent info guys, thanks!!

I am actually planning on installing an 80Gb Intel 320 series SSD and upgrading the RAM to about 8 gigs (which is about $80 bucks). That should do the job for me. The W520 is a no go for me at this moment because I'm looking for portability and with the weight of the T420 around 4.6-4.8lbs and its size, it's ideal for my needs.

The only thing that concerns me now is the screen quality of the T420, which I've heard isn't exactly of the stellar kind. I currently own a T60p and the screen on it is dull and depressing. I haven't ordered yet, but I'm hoping that I get the LG HD panel and not the AUO that people seem to be complaining about. My question is if I get the T420 with the 1600x900 resolution option, would that increase my chances of getting the better LG display?

 

Re: "if I get the T420 with the 1600x900 resolution option, would that increase my chances of getting the better LG display?"

Looks like you have to order the Nvidia Optimus variant of the T420 to get the LG screen, although this is not confirmed yet.

 

how are you getting the price. Could you please explain.

 

Not true. I have the integrated graphics chipset and have the LG panel, so it seems these two are not exclusive.

AMEX Daily Wish for $999 minus 10% using a coupon (+ ~10% CA tax). For some reason, it won't let me replicate the same thing again (just tried). But yeah, for $899 pre-tax the specs are really nice...

Wondering if it's worth $165 to go from i5 + 6GB + 250 GB 5400 Rpm to i7 + 8GB + 320 GB 7200 Rpm (and possibly get the "inferior" (AUO) panel) though. However, I really want my T420 to last me as long as possible, and so I'm wondering if the ROI on the i7 would be higher in retrospect...

 

Re: "Not true. I have the integrated graphics chipset and have the LG panel, so it seems these two are not exclusive."

Damn it, then It was a bad luck for me. How is the LG screen?

 

Well, I'd say it's a great screen considering that it's a Lenovo and a business laptop.

But then again - after reading a zillion posts here on the NBR I hate to admit that it is indeed very grainy... (but to be honest, I would have probably never noticed this if it was not for NBR)

 

Looks like you are too young to know smth about I-cpu or you were hell of not interested about presenting this new kind of CPUs in the past. I guess everyone who wanted to know more about new generation of intel I-cpus have already seen that images and schedules about I7 which was FULLY tested in TB mode, HT mode, TB+HT mode and without them at all. It was tested in archiving, gaming, and other tons of applications. It was made on Desktop I7. The result was that HT did either nothing or even reduced performance (1-2% but somewhere even 13%). Since then programs evolved however still HT may decrease performance especially in mobile CPUs, While TB is MUCH MORE effective in mobile comparing to desktop's one. So even 100hz will be very useful in non-multi-threaded applications (they still exist, can you believe?). It must be a shame for you that you were so sarcastic and sure while you were so wrong in basic knowledge.

I know that in video editing ssd give no performance increase because cpu is bottleneck before it limit even HDD speeds however not sure about matlab. I assume it will increase it.

P.S. I vote for SSD against CPU. You do not need i7. However why wouldn't you buy i5-2540 if it is possible?

 

If this is truly what you want, then what will stop you from upgrading the processor for lesser money later on down the line when you might feel you need more power? Hell, by then you might be able to get the i7 840QM for a little of nothing since they will be outdated by then if they are not already.

 

little bit optimistic I would say Have you tried to buy outdated cpu? Yes, of course they are much cheaper they were however now it is because they are relly slow comparing to nowadays technology. Besides, no matter how old CPU technology is, extreme models or one of the highest models of a product line are still very expensive considering how old they are and comparing to mid range CPUs of the same line. I7-840 is not i7-740 or i7-720. While last two may be really cheap soon I7-840 and higher will always be 1.5 more expensive (it is way approximately of course but I just want to show tendency). Everyone with very popular old i7(740,720) or i5 will try to buy this 840qm or higher. Remember demand and supply?

 

Indeed!

I agree with everything you just said...

Remember, TobaccoMan was just referring to an i7 over his i5. I kinda was referring to the one that would make a big difference, which would be the 840QM. Not that it is a necessity, but it is definitely a want!

 

I want it too! But I was also thinking to buy i7-640m and sell mine i7-740m. However mine quad is cheaper than that high dual core i7 one. Maybe somewhen I will trade mine on this one or buy 840m one.

And I agree that guy should buy i5 for now and if he will need he will buy i7 in 3 or 4 years

 

Aftermarket RAM and hard drives are relatively inexpensive; hard drives will keep on getting that way. If 250GB is fast enough and large enough for you now, I'd wait. 5400rpm drives are also quieter; for a long time I thought my ThinkPad's fan was a bit loud at top speed, and then I found out it was my Scorpio Black 500GB.

Some people would say the i5 brings a better ROI based on less heat and better run-time on the battery; ROI is a very subjective thing.

I think keeping your LG panel is worth it over risking a different one but getting an i7. That's just me, though.

 

Just as with the benchmark figures I mentioned, I will also take your tone with a grain of salt.

Beyond not understanding in what way my previous post was sarcastic, I am not entirely sure what you mean was factually wrong about it. The i5's and the i7 have the same feature set - including both hyperthreading and turboboost. The only difference between them is the i7's 1MB additional cache and 1-200MHz (depending on which of the i5's you're comparing to) higher clock speed, both with and without turboboost.

I would venture to say that the extra cache is probably, in most cases, more beneficial than the <5% increase in clock speed. But the main point remains that most (not all) users are likely not to notice a performance difference at all.

 

I probably would stick with the i5. You can opt to upgrade the cpu in the future but for now, I don't think its worth the extra premium.

 

Possibly with the T420 but I don't think you can with the X220, but don't quote me.

 

I already have an i5 2520 and I created a quote for an i7 (i5 2540 is not part of the AMEX Daily Wish deal). So effectively, I'm choosing between an i5 2520 and an i7 (plus a couple of other things). the way I usually code in Matlab (or Octave) is to minimize the disk activity to a minimum, i.e. I only save the final results when I'm done with the computational part (that's why I believe the impact of an SSD will be minimal, but with some shrewd coding tricks I can easily use both CPU cores to their fullest)

I agree I could always upgrade the CPU later. I'm just wondering it the price will drop enough to justify waiting (and more importantly, slightly lower productivity) for the next couple of years. remember, $165 extra is buying me not just the CPU, but also 2 more GBs of RAM, a bigger & faster (and most probably noisier) HDD, plus a fingerprint reader (that I'm never gonna use anyway). so a faster CPU is ~$100 at the most.

Not sure if you could put a quad-core CPU in a T420 (heating problems?). Anyway, I'm speculating that the high-end dual core i7 will be the most we will be able to use.

See above. We're effectively talking $100 or so for the CPU upgrade. I doubt the price will drop significantly below this, and as stated above this is without taking the increased (with i7)/reduced (with i5) productivity into account.

Well, I thought the energy consumption of an i5 vs. an i7 CPU is the same given that they both consume 35Wh (or whatever units we're dealing with here heh). So the heat should be the same and the battery life as well, right?

I must admit I'm fine with the capacity and the speed of my HDD. I also particularly like how relatively silent it is. Couple this with what could be the better HD+ panel of the two (I wonder if the two panels are really THAT different?), and you've got the two most important factors against getting a faster T420. If I knew I'd be getting the same panel + the HDD would be just as quiet as the one I have right now, I'd go for the i7 straight away... Unfortunately, it's not that simple...

 

I once followed this advice and went out and bought a 5400rpm HDD to replace my existing 7200rpm. I found the 7200rpm HDD not only quieter but had a lower pitch which I found much more pleasant. I returned immediately to my 7200rpm, soon to be replaced this time by a dead silent SSD (best upgrade I have ever made). HDD's differ in noise level and also in pitch, and this not just dependent on spinning speed. Reviews are a help, but in the end one has try it for real.

 

I get the lowest available, then sell those parts for new ones. So $165 is a lot, while 2GB more of ram is only around $19.

You can just about sell the i5 for the same price you will pay for the i7, at least in my case.

 

in the end, I've decided I'm staying with my i5 2520. while I wouldn't mind paying a bit more for an almost-maxed out T420, I just don't wanna bother with Lenovo CS again (I returned an X201 recently due to a defective keyboard and still haven't received the refund, plus they shipped my T420 to a wrong address, then redirected it to their warehouse and at the same time didn't want to pay for UPS to intercept the package and deliver it straight to me... and the list goes on)

thanks for your feedback, much appreciated

 

How the heck do you upgrade the CPUs later? Aren't most, if not all laptop CPUs BGA soldered to the board?

 

You've obviously had too many ultra portables in your life.

 

You choose a non-ultraportable laptop, like the 14-15" T-series.

You research the appropriate compatible CPU to match the socket of your system, and find the best combination of price/performance.

You buy the CPU off of Ebay (cheapest price, usually)

You grab some precision screwdrivers, an alcohol pad or two, and some quality thermal compound.

You download the Hardware Maintenance manual for your system.

You follow the instructions for CPU removal and replacement.


I've upgraded a fair number of laptop CPUs. It's too expensive to solder most processors to the system board; you'd have to have an assembly line branch for each processor/mainboard combination. Most mobile CPUs use a ZIF (zero-insertion-force) socket, and are put in during the build. The only systems that use embedded processors are ones that are tight for space, like ultraportables and netbooks.

Right now, Sandy Bridge processors are expensive sold separately. In a year or two though, prices will drop, and faster ones may be available at reasonable prices, especially when Ivy Bridge becomes the platform of choice. At that point, I might occasionally look at Ebay to find what the going rate is for a faster CPU than I have.

 

... or too much apples