i5-520M/i7-720QM: Please explain

This is bugging me. I need some clarification/explanation on this. Actually, quite a bit of questions, but all similar.

I know some of the basic differences between the i5 and the i7. Some being the cores/virtual cores, heat output, and integrated graphics option (which manufactures don't enable!). The one thing that I'm not sure of is the frequency (GHz) output they produce.

I'm looking at the Intel website and it says:

i5-520M
Base Frequency: 2.4 GHz
Max Turbo Frequency: 2.933 GHz

i7-720QM
Processor Base Frequency: 1.6 GHz
Max Turbo Frequency: 2.8 GHz

1) So, does that mean that with everyday things (browsing, MS Word), the i5 is faster? Even at max frequency/Turbo Boost the i5 is faster? The i7 is only faster when using all cores in multithreaded tasks (video editing)?

2) But also, does that mean that the i7 would be more effective in everyday tasks since it uses a lower base frequency (aka less power use/heat)? Something like the ULV processor of the ASUS UL series which are like 1.3/1.7 GHz?

3) Or is this all for nothing since frequency fluctuates despite of tasks, even during everyday tasks?

4) Also, what does "Embedded" meaning in the comparison table from Intel linked above?

THANK YOU!

 

-Yea, but it'll have very little advantage for the i5.
-No, quad core i7 only runs at such low frequency when all 4 cores are enabled. It'll use much more power
-If you do anything remotely resembling "load" applications it'll reach something at least near the base frequency
-Embedded means versions of the CPUs for embedded markets(like for industrial/medical/automotive) are available if you wish to purchase them

 

More or less. The i7 will be faster in processes where more than 2 cores are used, otherwise the i5 wins. But yes, for everyday tasks the i5 will be faster.

No. Look at the lithography: the i7 is a 45nm part whereas the i5 is 32nm. That means the i5 is roughly half the size and it's even smaller since there are only 2 cores so it runs a lot cooler.

It's not for nothing (the fact that it fluctuates doesn't change much), but the CPU is rarely the bottleneck of everyday tasks.

The number of reasons to buy a mobile i7 at this point is rather small. They're older (note that it's missing a bunch of instructions relative to the i5), they run hot at load (45W rather than 35W) and probably at idle too since they're 45nm, they have inferior single and dual threaded performance and they're expensive. If you need a mobile workstation that spends a lot of time on multi-threaded processes, then yes, they might be helpful... but otherwise, just stick to i5.

 

Well considering that the 720QM will run at 2.4Ghz, with 2 cores, exactly the same as the 540M, it is indeed a lot better, factoring in the extra cores and threads. The 540M will probably only JUST be better at single threaded apps, due to it's slightly higher clock speed, but it's not likely you'd notice the difference. It might even be that the 720QM is faster at single threaded apps, due to it's extra 3MB of cache over the 540M's 3MB.

And the 540M will certainly perform worse in highly multithreaded apps. I think you can be safely assured that with whatever you do, the 720QM is going to do it the same or better, depending on the task.

The catch with the 720QM is that it will run hotter, and will consume a fair amount more of power under load, and does not support on die graphics (Not that we've seen that yet in ANY new notebooks).

The i7 will turbo boost to 2.4Ghz when using 2 cores, so it will perform a little better than the 540M due to it's larger cache. The same could be said for single core operations, but there will be less of a difference, but the 720QM may only just edge out still.

 

The 540M is a different processor -- it runs at 2.53 GHz stock. But even if you mean the 520M (which is the one we were discussing), I am not entirely sure it runs at 2.4GHz when both cores are under load. I cannot find any information on this, but none of the other Core i5/i7 processors that I can find numbers on behave that way. For example, the Core i7 720QM runs at 1.73GHz when all 4 cores are stressed (the turbo boost pattern is 1/1/6/9 for 4/3/2/1 cores respectively) and the desktop Core i5 750 runs at 2.8GHz rather than 2.66GHz at maximum load (1/1/4/4).

The 520M will be slightly worse in multi-threaded tasks, yes, but I'd want to see some evidence before believing your last sentence. I haven't been able to find a direct comparison between the 520M and 720QM, but here is a thread about the 620M (also dual core, but at a 2.66 GHz base frequency and 4MB cache rather than 3MB) and here is a post where it is compared to the 720QM. As you can see, the 620M is far superior in lightly threaded loads and equal even in multi-threaded ones despite having fewer cores and less cache. Note also that it appears to run at an intermediate value (3.06 GHz) between the stock clocks and the maximum turbo frequency when both cores are active.

As I said, the number of reasons for getting the 720QM is small and after reading that 620M thread, it now appears to be approaching zero. The 720QM's problem is that its stock frequency is 1.6GHz. Yes, it has turbo boost and yes, it is quad-core... but when you start so low, the turbo boost will not reach the high-end dual-core CPUs and the extra number of cores merely allows you to equal them (1.6 * 2 = 3.2; 1.73 * 2 = 3.46). IMHO, mobile Nehalem never really made sense at 45nm -- it's a server architecture that works OK in a desktop, but it really needed the 32nm die shrink to work properly in laptops.

 

I don't know why so many are saying how much more expensive the mobile i7's are when compared to the C2D because overall, that is not the case. Take the NP8662 Vs their new i7 model update, the W860CU, there isn't much difference in price between them at all and the higher end 2.0 Ghz i7 is comparable in cost to the high end QX9300.

 

for best price and performance , i would get i7-820qm... the 720qm has too slow of a frequency turbo boost but the 820 has no problems with turbo boost and multi threading...

 

Actually, the best price per performance is the 540M. Look at reviews by NBR users (i7 dual vs. quad core) and notebookcheck (i5 vs. i7 dual core), and you will see performance isn't much better as you go above 540M, but power consumption and price skyrocket (almost exponentially).

 

Thanks a lot guys.

I guess the more I think about it and research, the Sony VAIO CW27 (520M) would be better than the Lenovo Y550P (720QM).

The heat on the Lenovo has been a growing concern for me. It's cold to the touch, but it's fan started to blow warm air even as I played a short video on Windows Media Player.

I guess luck will tell me whether the VAIO will actually last despite all the TLC it gets. Some say it's like a toy and there are random things that need replacing. Battery drain seems to be the most blatant issue.

PS: Of course I would want the new ASUS K42jr-a1 or K52jr-a1, but I'm running out of time!

 

I think that to back up my claim in my last sentence there is because the i7 with turbo boost will reach close to the speeds of the 520M, and the effects of the larger cache size may even negate the slightly higher clock speed of the 520M in Turbo Boost.

And sorry people, I did mean the 520M, not 540M.

IMO, best bang for buck processor is the 620M at the moment, for most people.

 

The review from notebookcheck seems to show that the 620M consumes quite a bit more power than the 540M and 520M, while offering only slight improvements in performance.

 

If that's the case, then 540M or 520M it is then...

 

intel Core i7 mobile 720Qm benchmarked

The overall results show that the 1.6GHz Core i7 720QM beat out the 2.8GHz Core 2 Duo T9600 and the 2GHz Core 2 Quad Mobile as well as many others.

In the gaming benchmarks, things were more even due to GPU dependency.

 

There's something wrong with Notebookcheck's review of the 620M. Not only the 620M has the same 35W TDP as the others, the higher end CPUs are usually better binned and consume less power in actual use. I would wait and see what other reviews say. The difference shouldn't be that drastic.

 

Quad core beat dual anytime the 820qm should pwen the 540M...

 

i say get the best proc you can get at the given time and keep that laptop for years. having a really high end proc will make your notebook more 'upgradable' to newer OS' as they are released.

the downside is that the cost goes crazy high for the notebook but if you average that out to like 4 or 5 years, it actually starts making more sense. this is good if you dont upgrade your machines often.

i bought two emachine desktops back in 2004 and they are still in use by my parents

the dv7t i ordered has the t9600 proc which was a $625 option at the time. this laptop has been absolutely stellar since i got it a year and a half ago. i plan on keeping it for like 4 years at least. 4gb ram is enough for now -- the only possible upgrade i may make is switching to dual 500gb SSD drives in 2013 when they're going to be like $100 each LMAOOO

 

Can i7 be overclocked? Manually.

 

Proof? Maybe try reading the other thread about dual core vs. quad core i7 w/ benchmarks.