i7 620M vs. 720QM

won't take any cpu with less than 4 cores in future no matter what.

 

Sure, quad-core is likely better for you, but your needs are very specific. Even then, the i7-720QM is only going to be ~30% better than, say, an i5-520M.

Also, the 820QM should be closer to 15% faster than the 720QM.

 

820 can be seen as same class as 720 for just a 15% difference in same 8 hyperthreading category, but is much more favorable than 620's 4 hyperthreading. more hyperthreading capacity is more critical here. i'm waiting for the delivery of second quad core machine and will see if it's up to the tasks later in coming week. current quad core works much better than previous core 2 duo's 2.6G machine for 10 threads real-time streaming but have yet to test 40 threads tasks as it's on another machine.

 

So why pay so much more for the 820qm? does the 8 vs 6 Mb cache make such a difference?

 

820 costs 180-350 more which is not worth imho.

 

yeah that's what i think....

 

Really don't want to hijack this thread, but I do have a couple related questions and this seems to be the best thread to tack on to.

I'm considering the new Thinkpad X201 that's just been released and it sports the 620M. Lenovo doesn't say which chipset its plugged into (I haven't called yet to find out). But over on the Intel site, it lists the 620M as an embedded chip. Is it safe to assume that if I get this model, that if I ever want to up the chip, I'm going to have to swap out the entire board? (Not that I'd necessarily want to, but just to help me understand)

The X201s runs the 640LM - the 25W cousin of the 620M.
They're both dual core chips - and the 640LM clocks up to 2.93. Am I really going to see an appreciable difference in performance by going with the 620M?
Typical usage would be: half a dozen simultaneous Excel/OpenOffice spreadsheets (from 4-12Mb each), some cycle-hungry energy modeling software that is probably too old to be able to take advantage of any multi-core/multi-thread processing, occasional Photoshop/GIMP work, some Google Sketchup work, background has Dropbox/Syncpliticity taking up cycles too.
Don't need discrete GPU, am fine with integrated.

Also, the 640LM is not listed as an embedded chip - something to consider if I want to swap it out?

I'm looking for something below 3lbs and sub-13" screen to fit the usage profile above. I haven't seen any i7 quads that have been fit into such a small machine - I can't figure out why Alienware didn't put something better than the C2D in the M11x...otherwise I'd consider it. The (soon-to-be-released?) ASUS UL30JT may sport an i7 - can't recall if its dual or quad.

 

I'm in the market for a similar machine, only I tact on high res screen *and* dedicated graphics.

IMHO, quad core i7 isn't going to help you much and I would go with the 620. The idea of processor replacement is enticing but its likely not worth the cost. You are looking at trying to find a source for processors that in 1K cost $330+. Unlike the desktop market, competition is light and they mark up the cpu for resell quite a bit. even then the performance gain would likely be minimal.

I too was excited for a quad core but after reading reviews and real results, the 620 or even the 540 is the better choice.

 

so what models are you looking at?
Is the proc. on the Alienware M11x good enough? (Its running the 3-series NVidia)

Any other brands/builds that fit the size profile?

 

just confirm i7-720 works great in 20+ threads cpu demanding tasks, never had freezing moment like previous core 2 duo did, no need for i7-820 or i7-920 upgrade here.

 

Felt like I should not create a new thread as this follows along the lines of this one.
Should I get the i5 540M or i7 720QM.
My usage will be for gaming and I know most games do not have quad core support.
The thing is, if I get the i7 the laptop will come wit a USB 3.0 port, but if I choose the i5 it will not.
Is the performance in games of the 720QM worse than that of the 540M because the i7 has less GHz. I know the i7 would perform better for quad core tasks such as video editing, rendering, or multi tasking, but I want to know if it would perform better in games due to the fact that it has less clock rate but more cores. I fear the cores would go unused as games do not support them.
Is the 720QM worth it over the 520M in this case?

 

There are a number of games with quad-core support, but even so many of them don't use four cores anywhere near as efficiently as they do two.

Overall, I'd expect that you wouldn't notice the difference between them in almost all games, whichever one happens to be ahead. It's up to you whether you want to pay more for USB3 with the more power-hungry i7.

 

Price/performance wise. The i5's are more than enough juice for almost all users.

The i7 is designed to be squeezed and used...otherwise it is wasted all that power.

JCortres. Games are mostly GPU-bound...that is not likely to change (GTA IV and some others do require powerful CPUs though). I think that you have to see some things.

If this is a laptop you plan to keep for a LONG time to come, the i7 (mostly for the USB 3.0) could be worth it. But take price into consideration. I highly suggest our dedicated forum "What notebook should I buy?" for this type of questions. People can help you there more once the FAQ/FORM is filled.

And welcome to the NBR Forums.

 

If the 620M is pulling ~65w under heavy load, that is as much as the 920XM pulls under a heavy load. I'm not sure idle is of much use, since even 920XM drops down to 18w.


If heat/battery life is of concern, I'd stick with the 5XX/4XX/3XX chips which pull a significantly lower amount of power under load (~50w). ~23% reduced consumption in both power draw and heat is major IMHO. You also get some good performance out of the 540M.

 

I opted for a 620m over a 720QM. Did a lot of reading and research. Most benches favor the 620m. Only heavy, heavy multithreaded benches gave the 720QM an edge. 4 threads at 3ghz over 8 at 1.6-2.0ghz any day.


I must add to those who are seeing power tests? are they testing with or without the integrated graphics running? It adds about 10w. In my case the Dell laptops dont have the graphics core enabled and its not in use. So those power ratings wouldn't be accurate for me.

I'm pretty sure the reason why you're seeing a high power rating is because the IGP is in use and on the high end models (620m) it runs @ 733mhz?

 

electrosoft, where did you get those numbers from?

 

The GPU will reduce your gaming performance regardless of your CPU 90% of the time because you will be looking at your graphics more than your CPU needing a faster clock to operate a game lol. Look at the processor Min and Req requirements on games in the last 2-4 years, hasn't been a big gap in performance lol.
In my opinion the quad is the better choice. Practical application of the CPU is the prevailing issue.
Think of it like this, both CPU's are far beyond what any game now a days needs. If your like me, you'll run a game, and a messenger, and Chrome or Firefox watching videos or listening to music. The 64 bit OS and a small SS drive (with your super 2 TB external if you have pics and stuff) will make everything pop up in a snap. A good amount of memory and the multiple cores with the higher bus is the total win here. In 5-8 years i'm guessing you'll be able to run simple online apps while you bought a new desktop replacement to run games.
I'm looking forward to getting a SSD and upgrading from a i3 soon on my next laptop. The i3 330M is performing better than my old core 2 duo and its running plenty of excess load.
Mobility HD 4870 (X2 would be even better i'm thinking) will get it done for your games laptop wise. The more multiple cores are utilized in the future, the more quad will pull away for multi-tasking.
Good luck on new laptop! For the same price the Quad and higher frequency memory will win out when your unit gets dusty and runs sluggish lol

 

4 cores at 1.733GHz vs 2 cores at 3.067GHz is at most 13% better, but in most situations significantly worse. The lower memory latency due to Clarksfield's memory controller is a nice boon for the 720QM, but it doesn't win out against clock speed.

I'd pick the i7-620M over the i7-720QM, but really I'd rather save some money and get a Core i5 or i3 because they're much cheaper.

 

i7 620M =2.66 GHz (3.33 GHz turbo mode) only 4MB cache
i7 720QM=1.6 GHz (2.8GHz turbo mode) only 6MB cache

 

Why does the memory speed doesn't matter. 1333 is faster then 1000?

 

Because in testing you don't see any actual differences. 1333 is 'faster', but it's accompanied by larger delays accessing the actual memory locations (CAS latencies and such), so it ends up mostly as a wash.

 

thanks for your fast reply,

In that case I think I will go for the clevo (xxodd) 870cu, with a
i7 620
ATI Mobility Radeon HD5870
and a Intel X25-M Postville (G2) ssd.

This should be a fast enough system.

 

That will be a fantastic system.

Will be the exact same specs as my M15x come Monday

 

Memory speed doesn't matter because even the slowest speeds are faster than the slowest component, hence it won't be bottlenecked. As an analogy, what's the point in increasing the speed limit, if your car can't even hit it?

 

Well, the frequency of the RAM doesn't matter too much because the higher the frequency the slower the timings.

So it evens out, basically.

 

Yeah, you typically get similar latency, because timings are measured in clock cycles, but obviously clock cycles are shorter at higher frequency.

 

It all evens out in the end.

That is why I don't really care whether I have 1066 or 1333 memory in my system

 

You know this discussion reminds me of some of the single vs dual core arguments and how the dual won out over time, P4's where the bomb even over the core 2's on early clock rates. Now the more people use em and get programing for it the better it preforms. I guess its to see if it gets utilized and how soon. I got my M15x in the mail now, cant wait!

 

Considering the architecture is essentially the same for the models in comparison, I don't think it's quite like the P4 vs. CD argument.

 

imo its not really an issue of architecture but software optimization.
during the p4 vs c2 days it was a question of single threaded vs double threaded software optimization.
nowadays, its a question of single/dual threaded vs mulitcore optimization.
and just like the p4vsc2 days it will just be a matter of time till this argument becomes moot.

 

Indeed. Mind you, the current situation for desktops is quite different than it is for laptops - in a desktop, I'd definitely recommend buying a quad-core if you can afford it.

Consider the comparison between the desktop i5-750 (the cheapest Core i quad-core) and the i5-661. They both cost the same amount of money, around $200, but the gap in clock speed is far less between these two than it is for the laptops. Factoring in the Turbo Boost, the i5-750 does 2.8GHz on 4 cores and 3.2GHz on two cores. By comparison, the i5-661 does 3.467GHz on 2 cores. Comparing based on raw power alone (ignoring the effects of Hyper-Threading, which the i5-661 has but the i5-750 doesn't), the i5-750 is around 8% slower on two cores, but on four cores it has a whopping 60% more raw power.

As such, on a desktop it's obvious that the quad-core i5-750 is a vastly better choice than the i5-661. On a desktop, the i5-750 is probably the processor I would most recommend to those that can afford it, because it's extremely good value for money - mind you, if you're looking for a gaming desktop on a budget you'd still be better off saving money and going with an AMD system just because that would free up more money to spend on the graphics card.

If we apply the same comparison between the i7-720QM and the i7-620M, things are different. The i7-720QM does 1.733GHz on 4 cores, and 2.4GHz on two, while the i7-620M does 3.067GHz on 2 cores. This means that the i7-720QM is 22% slower on 2 cores, but on 4 it offers the potential for only 13% more raw power.

It's obvious that desktop quad-cores and laptop quad-cores are very different kettles of fish.

Some caveats to go with these calculations: When I say "raw power" what I mean is simply the clock speed multiplied by the number of cores. Basically, it represents the relative amount of work the CPU can do in a given period of time against other CPUs with the same architecture, if all cores are running at 100% with no redundancy. The reason people don't usually just multiply clock speed by the number of cores is that no real-world application is infinitely scalable. It's essentially guaranteed that if you go from two cores to four cores then, all else being equal, you won't quite get twice the performance. What the "raw power" figure represents is an upper bound on the performance advantage of the quad-core, which is a useful consideration only for applications that are capable of using 4 cores extremely efficiency - 3D rendering comes to mind.

However, it's crucial to note that the only reason it makes any sense at all to compare these chips based on clock speeds is because they have essentially the same architecture - they're all Nehalems. Clock speeds may not be the be-all and end-all, but a 3GHz Nehalem is 50% faster than a 2GHz Nehalem if all else remains equal. Granted, there are differences between the quad and dual-core CPUs we're looking at here, most importantly that the quads include the memory controller on the same die as the CPU, while the dual-cores have two dies, one for the CPU and one for the IGP and memory controller.

Consequently, the quad-cores do have the advantage of lower memory latency and greater memory bandwidth, which isn't entirely covered by raw clock speeds. That's why benchmarks are important here as well - in some memory-sensitive applications, this difference will give the i7-720QM an edge that cannot be accounted for by the calculations I did above. Nonetheless, if you look at real-world benchmarks comparing the i7-720QM and i7-620M, you will see that this advantage is easily negated by the i7-720QM's low clock speed and real-world limitations that make it difficult or impossible to use 4 cores as efficiently as 2.

 

Ok, so I just ordered a M15x and went with the i7 720qm, my reasoning was it last longer because eventually programs will make more use of it then the i7 620m, also it will have less dpc latency problems, and it would be good for music production and for playing music live through a serato box or what have you. Then I came to this thread and see overwhelming support for the 620m. So am I wrong in any of my reasons of why I got the 720qm, and I looked at the benchmarks and the 620m is higher on the list but all of the numbers for the 720qm are higher except the "Cinebench R10 Rendering Single" so I don't understand that either so could someone explain that?

my benchmark source: Notebookcheck: Mobile Processors - Benchmarklist

 

Quad core!

 

i think you made the right choice.
just as you said programs will eventually be optimized to use more than 4 cores.

 

P.S. - On this link it seems to show the 720qm higher aswell. Notebookcheck: Intel Core i7 720QM Notebook Processor

 

That's the point. In a setting where I need 2 virtual maschines I'm happy to get 4 cores and 8GB ram (4x 2GB which most mobile workstation only support with a quad core) so I can use 2 cores and 4GB ram for the virtual maschines and still have 2 cores + 4GB for my main system. The VMs won't use much CPU power so I still have 2,4-2,8GHz for my main system

 

did he also mention way higher power usage than i7 quad? IMO , the i7 quad is a futureproof option... its also power efficient shutting off cores when not needed... anyways , the M15x and most notebooks can't use the integrated graphics... as it is disabled by manufactuerer.

 

I tend to disagree.

by the time most apps are encoded to take advantage of 4 cores, people will find 1.73GHz/core to be too damn slow for anyone to be meaningfully interested in. As in, people buying either the dual core or quad core 2010 laptop CPUs will be looking to upgrade in a few years, period. And I don't suspect either crowd will really have had a better 3-4 year experience than the other crowd.

Perspective: I remember back in 2005-2006 when everyone was jocking AMD's first release of x64 CPUs. At the time they were the only ones on the market. Salesmen said the same thing then: buy the x64-based system instead of the Core Duo machines because the x64 chip would be more "future proof". Well. Anyone really think the people purchasing x64 chips felt "future proof" in 2009 with their low clockspeed? Anyone think they had a better experience than the Core Duo purchasers? Of course not. By the time meaningful amounts of software came x64 ready, the clock speed of their now old x64 chips made them irrelevant. Meanwhile, their CPUs performed many things slower on a daily basis during their lifetime as they waited on the salesman's words of a future where their CPU would always outperform those Core Duo's to finally come.

Point is, "future-proof" amounts to self-deception in the context of CPUs in computing. Get the clocks unless the software you use on a daily basis is optimized for quad core CPUs. For most people, that means i5 or i7 dual core. If you are one of the small % of people who need quad core power, have tried both solutions and find the quads better for you, go quad and don't look back. But don't try to predict the future...that X or Y app will be 4-core optimized in Z years; it's foolishness. and sleep better at night.

$0.02

 

For 90% of apps and games the much much higher clocked 620m with 4 threads will smoke the quad core. I'm certain 95% of the users here would benefit from the dual core more then the quad. Plus cooler temps and longer battery its a win win.

 

I fully agree with this statement. I buy my hardware at max specs to run my currently apps at max. If I need quad core in the future I change to quad. It's that simple.

 

I just returned my Dell Studio 1557 with Core i7-720QM for a replacement Studio 1558 with Core i7-620M. Here's what I found:

The Core i7-720QM sits around 50-60 degC and draws 15W at idle
The Core i7-620M sits around 45-50 degC and draws 6W at idle

The Core i7-720QM maxed out at 88 degC and up to 55W under full load
The Core i7-620M maxed out at 80 degC and up to 28W under full load

All figures from CPUID Hardware Monitor.

I find the Core i7-620M much cooler and a lot more stable than the 720QM, I had a lot of overheating problems with my Studio 1557 720QM.

I also find the 620M faster in day to day use. The majority of programs are still optimised for dual core, even video editing software and filters with only a few video filters being optimised for quad core. I really notice the extra GHz in the dual core i7-620M.

Really the Core i7-620M runs a lot cooler and is faster in most applications than the 720QM.

 

This what I always preach. The i7 620M uses less power and is in normal use faster than the i7 720QM. Also in gaming you don't have some advantage of the four threads. Almost every game uses just two of them. Only when you run a lot of applications at the same time or photo editing, that kind of software...

 

I fully support all of the above!
Unless you are doing some having multi-threaded work, the i7-620M is definitely a better deal.

 

Anyone have a short list of notebooks with the i7 620M current and soon available?

 

Pretty much every notebook that supports a 35+W i3/i5/i7 will support the i7-620M with very few exceptions.

 

i have returned 3 laptops with i7 720qm as it throttles in most applications down to a 7x multiplier and locking there for quite some time not to mention over heating , i have finally settled and gone with the i7 620m and my life is much happier now that i have made the change

 

the overheating is more a function of laptop design than the cpu itself and the throttling is also dependent on whether the programs you use support multiore or not.
i have neither of these issues

 

No. The overheating is solely because of the processor.

 

no. the processor does run hotter than a 620 for sure but it shouldnt be overheating. that is due to a laptops thermal design, or lack of it.

 

They aren't going to put in a completely different cooling design just for i7-720qm models, so you can't expect it to cool perfectly for something that generates so much heat. It's different if the standard on it is an i7-720qm, but otherwise it's the i7-720qm's fault.