i7 620M vs. 720QM

Just a quick update regarding GTA IV and Hyperthreading. I just flashed a Mysn Bios on my laptop which adds overclocking (for extreme processors) and advanced chipset functions. I disabled Hyperthreading through here and GTA IV now shows 86-94% CPU usage during play and in the benchmark. The 50% it was showing when Hyperthreading was enabled would have been taking into account the 4 extra Cores it was seeing just as I thought.

 

I had a little trouble following that post, LaptopNut. Does this mean that the Hyperthreading cores really did help, or that they just messed up the reading of what percentage of the CPU's power was utilized?

 

Hyperthreading just makes the benchmark CPU percentage results slightly misleading if you don't realise that it is for 8 Cores as opposed to 4.

I don't expect any performance differences with Hyperthreading disabled but when I play for a while I am sure I will notice if there are any.

 

I responded in that thread, but I'll say it here:

Hyper-Threading doesn't "split the core in two", it makes two virtual cores, both of which correspond to the same physical core. If only one of the virtual cores is in use, it gets the full power of the physical core, while when using both of them you can potentially get ~30% more than from just one virtual core alone, since the superscalar architecture can allow more of the core's resources to be used at once when there are two threads to use them.

This is in keeping with your GTA IV testing - although you reported 50% usage with HT on, in fact only one virtual core would have been used for each physical core, which would mean you were getting full power out of your CPU. As such, you would expect the results with HT on to be pretty much the same as with it off.

 

I can buy a i7 720QM for $200US and the i7 620M for $260. A lot of forums say the 620m is faster for gaming. If this is true is it worth spending an extra $60 on the 620m? Is it actually faster in gaming only because that will be my only use at the moment?

 

LaptopNut - Hopefully you still take a look at this thread as I have a question pertaining to your last comment about FSX. I'm trying to nail down what specs I want in a new desktop replacement class of laptop, and FSX is one of my concerns. I've searched the web high and low for performance reports on FSX, and know not to expect miracles. I will do some gaming on the laptop, such as FSX, FS9, Silent Hunter 4, probably some other older flight sims and racing sims that have been on my shelf for a while. Also some DAW music production and home video editing. I honestly think an i5 540m will cover most of my needs at a much lower cost than an i7 - but FSX always has me questioning it. Typically MSFS likes Ghz, but as has been mentioned SP1 and/or 2 for FSX added some multicore support - though my understanding is that it doesn't use it very much. So I just want to make sure I'm following correctly - from your observations with the i7-620m FSX seemed to run about the same as it did with the quad? I know the 540m ranks under the 620, but I don't think by very much, and there's a new i5 580 that's on the way to replace the 540 that has the same clock speed as the i7 620 (which I think will also be replaced by a faster i7-640). The 540m where I've seen it offered is significantly less expensive than the 620, so I think that's where my sweet spot is on the price/performance curve...... as long as it will at least run FSX decently (I'm just not going to do the 4Ghz overclocked quad core desktop with liquid cooling that people say is the only way to do FSX well). I believe them when they say that's what you need to max everything out and get high frames, but I don't need to max it out to enjoy it. Sorry for the longish post, but I like to try to give some background as to my intentions for the computer instead of just shooting out "what's better?" And your direct comparison of the i7-720 and 620, or more importantly for me quad vs dual, with FSX, is exactly what I'm looking for.

By the way - do you recall generally what your FSX settings were when using the dual core?

 

@ MetalMania

Yes the i7-620m did run the game about the same as the Quad did but that was due to the mobile i7 820qm's Turbo Boost which can go up to 2.8 Ghz on 2 Cores but due to the multi core patch, this would have been fluctuating more than it would have without. The settings I used were a native resolution of 1600 x 900 and everything on Medium - High, AA enabled. In previous benchmarks with the Core2Duo architecture, there was a difference of about 7 fps or more when going from 2.0 Ghz to 2.8 Ghz so bare that in mind. You also want a strong GPU so don't neglect that.

The 540m will run Fsx fine but you will get less fps than the i7 620M. 7 fps is not worth an extra $100 or £100 though.

Since we got good results with a 2.8 Ghz Core2Duo, I would expect the 540m to get similar results because it is a newer more efficient architecture. Depending on how long the new i5 580 you mentioned is due to be released, I would maybe wait for that.

So to summarise, Fsx without the slightest doubt prefers a higher clock rate over a higher number of Cores but we are no longer in Core2Duo Vs Core2Quad times so the mobile i7's Turbo Boost can match any Dual of a similar clock rate without any problems.

DAW music production and home video editing will probably perform better on a Quad but if it is more of a casual hobby then it won't be worth buying a Quad over the Dual to save a few minutes.

So go with either the 540m or the new i5 580. You should take a look at the 2.8 Ghz Core2Duo Vs 2.0 Ghz Core2Quad Fsx benchmarks in my sig. People were surprised when the Dual beat out the Quad every single time.

The mobile i7 Quads offer the best of both worlds but that comes at a price.

 

Thanks for the info, I feel reassured! I agree with your assessment of the i7 Quads being the best of both worlds.... if you can get the 820 or better. The reason I feel that way is that in dual core mode it runs up to 2.8 and single 3.06 - which is actually the same as the i5 540 but with the additional L3 cache. My self imposed price cap pretty much limits me to only going as far as the i7 720 (and therefore 620 as they're about the same price). The 820's are at least a few hundred dollars more and the 920's.... forget it! Maybe if I could find them relatively cheap aftermarket in a couple of years, and if they could plug into the motherboard I'll likely have with a 540 or 620 (probably PM55 I think it is?)

If you don't mind another question, again focused on say the i5 540 pertaining to FSX, do you think the 3MB L3 cache and slightly more latency of the i5's memory controller vs the i7's 6MB (for the i7 720) would have a perceivable performance difference when running 2 cores? I guess what I'm wondering is if the i7-720 running 2 cores at 2.4Ghz with more cache makes up for the higher clock of the i5 with less cache. And I guess that only applies if the 2 running cores on the 720 have access to ALL of the 6Mb, or if it's split evenly between the active cores - which would then make it exactly the same as the i5 .... and slower!

Is the cache worth the cash? (Sorry, couldn't help that one.....) I'm almost sold completely on the i5 dual (or i7 620 for a good deal), that last question about the 720 and cache when on 2 cores is my last nagging doubt.

 

I don't think the extra cache will make up for the slower clock rate and I have never seen any benchmarks or general gaming performance to suggest otherwise. The other issue is the i7 720qm is likely to run on 4 Cores at 1.73 Ghz due to the Fsx Multicore patch. I don't know much about cache in relation to gaming performance but some suggest cache doesn't make any noticeable difference in gaming at all.

As long as you have no plans of playing GTA IV, going with the Dual will be fine.

 

for pure gaming, the 620 would be the better choice atm.
the 720 is a better all around cpu as others have suggested, but for just gaming take the 620

 

+10000000


Don't pay anymore than what you need for your NEEDS T O D A Y..... Benchmarks and Specs mean nothing of they are not realized in a meaningful way. You cannot "future proof" technology that moves this fast.

Tomorrow there will be a whole need set of specs, processors, on and on...and remember MOST games and software are not optimized for tomorrow. In fact most are optimized for people who are running systems a year old or more. Imagine the lack of software sales if one could not run todays software on yesterday's PCS. Flight Simulator X made the mistake of programming for the futures and that franchise is over, People are running back to FS 4 and it has been years since FSX came out and it still cannot run on full graphics on many machines!!!

Buy what you need for today. IF you run Sonar (as I do) for music a Quad will benefit. I use it in my desktop builds. But in my notebooks I am looking at buying a Refurb Dell M6500 likely with an i7 680 or i7 840....The 720 is dead in the middle. This machine would cost nearly $3000 new....I will pay less than $1400 to my door. All compaonts can still be configured.

FSX is far more processor oriented than GPU. That is why it has been a major issue to run with decent FPS at high settings. That is also why they don;t use it as a benchmark for video cards.

Anyone who has been around long enough knows replacing a processor without a new socket si something that is rarely done. Usually to gain the benefits of a new processor one needs a new chipset which adds other features which necessitates the need for a new motherboard anyway...and maybe ram and a power supply on and on.....

Buy for today....NEVER buy the bleeding edge. Buy the time you need it it will have passed you up....All the TOL stuff is good for is bragging rights and those who live and die "comparing benchmarks" rather than real world use.

 

kingfrog,

Couldn't have said it better myself!

+ rep!

 

Many years of experience buying and building PCs. I have ALWAYS found whatever I buy today will be old in three years.....

What good is a $1000 Quad Extreme at $3000 today when in three years that will be a dog. (and the benefits realized today are not at all that great for 99% of 99% of what people do (except of course when posting "benchmarks"?
Most games are made to run decently on 3 year old computers as is most software. Look at recommended specs on boxes. Not minimal and find old processors and GPU specs. FPS over 30 is wasted to these eyes as is 1080P resolution on a 17 inch screen. IF I have to use windows to increase printsize my resolution is wrong. If I need extra windows I add a monitor. My studio has one 27" Monitor and two 19" ones.

I have decided I don't need a Quadcore TODAY in a notebook and I have been editing Video and doing music remote multi audio tracking using an E1705 with a T7200 and 5900GS and even running FS4 and SIMS 3 on ot flawlessly. I am more than sure even an i5 would be light years faster. But I will probably go for the i7 640 in my next lappy. IF I wanted a quad it would be the the 840 at Min. I do not see any useful advantage in the 720 over the 640 in everyday tasks. The extra advantage is nill. So a Video renders in 10 hours instead of 8? LOL Will I REALLY be photo shopping while playing a game and browsing the net? Have I EVER had to do that?

People with Iphones don't have much issue running one app at a time.

That said on my desktop which I use primarily for Multi track Audio recording in a home studio uses a Quad Chip. Sonar makes use of all the cores as does Vegas. HOWEVER the Q6600 is doing fine and at this time I see no reason to upgrade it and the mother board. I get all the tracks and softsynths I need. Would an I7 render faster? Yeah but how much. For me it would have to render an hour file in 10 minutes to make to move and I don't think I will be there for another three years of technology. A 20% increase in performance is not enough to go through the hassle of rebuilding.
The Q6600 does fine at stock speeds.

All this teeth gnashing over 11% more power at MAX is crazy. Temps are more important. Low temps mean less headaches. Operate BELOW the thresholds of power available and keep your sanity,

 

Hi All,

First of all, great explanation there kingfrog!

And sorry if I am double posting, but I would like you suggestion as my query is a somewhat similar but a bit different.

For my issues (throttling / heat) in current system, I have to tell DELL about my replacement choice b/w 1645 (i7-740QM) vs 1647 (i7-620M).

I am thinking of going with the 1645 (with 1GB DDR3 ATI Mobility Radeon HD 5730) as my main aim is a generic system - basically running VMWARE machines for development / sound editing / photo-shopping / moderate gaming (Half Life/GTA/CRISIS and so on)

Should I place my bet on the 1645 (with the 740QM)?

Let me know please, Thanks!

CK

 

between the two just go for whatever is cheaper, and last i checked it was the 720qm which was cheaper.
if you are just doing normal stuff, just get an i3

 

Thanks for the reply! Actually I am not PAYING anything for either of these. It is the replacement being offered by DELL.

That's why I need to decide.

CK

 

if your not paying and its between a 740 and a 620 go with the 740 since you do vmware.
also resale value could be better for the 740 if you decide to upgrade down the road.

 

@trvelbug: And how much would be the HEAT and THROTTLING difference / comparison be between the two?

Would I be able to play games like HL2 / crisis / GTA 4 as well on the 740QM as on the 620M?

Thanks!

 

heat and throttling is more a laptop design parameter to me. for example my sager with a 720qm is cooler than my girlfriends core2duo 2.26 macbook on idle or heavy load.
i really cant comment on the dells heat dissipation qualities, so you your best bet would be to post on the dell subforum to get actual user feedback.
i also dont play the games you listed, but among them i know gta iv plays much better with a quad/multicore. so if gta iv is important to you and the dell can handle the thermal output of the 740 without throttling then the 740qm is the obvious choice.
imho between the 720 and the 620, the 620 is a better choice for most normal stuff and gaming; assuming that the 620 is equal to or lower in price.
between the 740 and the 620, the 740 is the better all around choice assuming that your laptop can handle the thermal load, battery isnt important to you, and your getting them at relatively the same price (or free as you are).

 

The 620M will not handle GTA IV well at all. Not without some kind of custom config or non standard methods anyway.

 

i would still get the 720m for a bit of fututreproofing.
we are well on the way to a multi threaded computer environment (hardware and sofware) in a year so; or maybe even less, and a 720qm should have an advantage.
some people here have said that well then get a notebook when the technology is already there! sure that would be ideal.
but what if you need to buy a notebook now and want it to last at least a while and just cant replace it every time new tech props up- just as most people in this thread are planning to do. i think one of the reasons threads like this are so prevalent is that people want to know whether their cpu/tech will be viable for a couple of years or so.
do you guys think that we will still get threads like this (aka 2 vs 4 core) in sept 2011? how about sep 2012?
sure a year from now both cpus will be struggling compared to newer tech, but what do you think will be struggling more?
so if you plan on using your computer for more than a year i suggest getting a quad, even the 'measly' 720.
however if you plan on changing your computer in a year; or plan on using 2010 software for the next few years - get the 620.
plus isnt the 620 more expensive?

edit:
if you want to get a cpu for 'normal' stuff just get an i3 or i5

 

I wanna buy a laptop
If i only use VMware virtual program.
Which CPU would be good about i7-720qm and i7-620m

 

i'd get i7-720qm.. always... it should be better..

 

i would get the i7 620M anytime over the i7 720QM

first, because the i7 620M seems to be better than the i7 720QM for dual core demanding applications
(when tested with the dual cores coresmark benchmark I get a better result than the i7 940XM at stock clock)
(I have got a better result than the average of the i7 720QM results in passmark benchmark as well which is not a dual core only benchmark but I must say that I am way above the average of the i7 620M results for this same passmark benchmark)

secondly, the i7 620M seems to be less hot due to 32nm process technology (means less fan noise, results could vary depending on the laptop but from start we're dealing with a 35W vs 45W TDP)
(I get very low temps for this cpu 37C idle, 68C benchmark temps)

thirdly, because it has an integrated graphics (which could help some people but is useless most of the time if you have a strong discrete gpu)

then, because all what I ask the i7 620M to do, it does without failing

and finally, because the several more multi cores related benchmarks that I have used doesn't show a significant or even an existing advantage for the i7 720QM over the i7 620M even when dreaming at futurproof considerations
1 or 2 years from now both will possibly be obsolete for some demanding applications so then an i7 920XM or 940XM or whatever extreme processor will possibly be a good choice to keep the pace
even when looking at selling possibilities 2 years from now prices will possibly be so low that it will possibly be too close to call but I repeat it's just hypothetic we don't know what the futur will be yet

so then when taking all these things into account an i7 620M is a better choice right now

Nevertheless, I must say that the i7 620M is currently sold in average at a higher price than the i7 720QM on ebay and the i7 640M is currently available as well at ebay stores

why making your choice from what you don't know (the futur) rather than what you know and what you need now?

 

@erig007,
i7 620M is manufactured at 32nm technology. And the die size I think is 195 mm squared ? (Can anyone confirm?)..

 

you're right 32nm and the processing die size is 81mm2
Intel® Core? i7-620M Processor (4M Cache, 2.66 GHz) with SPEC Code(s) SLBPD, SLBPE, SLBTQ

plus 114mm2 for the graphics and imc

for a total of die size of 195mm2 like you said if my result is correct

 

Yeah, that plus the IMC and Die Size (114 mm2 @ 45 nm) would make that total die size 195 mm2, right?

 

i wanna buy one of this two: 620M or 720QM. for me the most important is which one is better in fritz chess benchmark. does anyone has test results ?

 

Guess I might as well throw in my two cents.

I went with the 620m. My laptop hasn't arrived yet but I'm happy with the decision. I feel like I'd rather have 2 really super fast cores than 4 average to slow ones. Especially because I play games and no game I own runs on anything more than 2 cores, quite a lot are even single core. X3:Terran Conflict in particular is both single core and very cpu demanding so I think I made the right choice for my own needs.

-Poobs

 

See:
Fritz 9 Schachbenchmarks


See:
http://forum.notebookreview.com/har...arket-upgrades/455347-i7-620m-benchmarks.html


So, i7 620M has Fritz score of 11.50 (5518) and i7 720QM has Fritz score of 11.76 (5646).


Without even looking up these scores I guessed the true quadcore would be the better/faster one.

My i3 350M scores 8.49 with 4 cores (2 real + 2 HT) and 6.32 when only using 2 cores.

So, with a 'win' of only 2.26% faster (in Fritz), the i7 720QM it is...

 

I confirm the Fritz score result for the i7 620M as I get 5615 which is a little bit lower (0.55%) than the value of 5646 that the jens.tauchclub-krems website shows for the i7 720QM

 

jens.tauchclub-krems website = big mistake for 720QM test

my friend has Toshiba Satellite A660-10X with 720QM and his score in fritz benchmark is 13.21 / 6342 Kn/s

if we compare to 620M - 5615 score the 720QM is 12,94 % better than 620M




I'm interested in Toshiba Satellite A660-17G with 740QM so i looking forward to be a bit faster and i think it's the best choice !

 

I've seen SFA benefit regards "futureproofing" from my i7-720.

Nothing is optimised for a slow multicore over faster dualcore. Very few games use 3 or 4 cores on any consistent basis (GTA4 is one example that in my personal experience ran smooth as butter @ High 720p on this G51J, ran choppy as hell @ Med 1080p in places. It's not all about CPU.)

That said if it's only a few bucks more than an "equivalent" speed i5 (e.g. 540M) go for it. The one direct bench I did (520M vs 720QM, 7Zip benchmark) showed an advantage to the 720qm that could not be explained by clockspeed alone in a direct 2-core contest (the 720 was locked to running it on 4 threads over 2 cores as would be the 520M) so there IS an advantage.

---

Hyperthreading's advantages are never seen in gaming, never have been ever since it was on northwood P4s. The parts of the processor pipeline that are duplicated are simply of no benefit to the processor workloads seen in games.

Look at the CPU logs after playing any game, you'll see the total of logical core pairs 0+1, 2+3, 4+5, 6+7 will always add up to 100% (e.g. 0=80% utilisation when 1=20% utilisation is no different from a 100% utilised physical core), when HT is giving benefit those core pair totals will exceed 100%.

A 25mb xlsx with >100k complex formulae is a totally different story though. Only time I've seen my quaddy run at 100% (other than a bench).

 

I wouldn't get either at this point. I'd get i5 520M or i5 450M. These aren't that much behind the i7 620M to consider the huge £110 price premium. They are also Arrandale so they have integrated graphics for graphics switching. Arrandales in general produce less heat and consume much less power at idle and load states than any Clarksfield.

In summation, the Arrandale is the closest thing there is until Sandybridge to a cpu that was designed for notebooks. Clarksfield by comparison has the smell of a cpu that was designed for desktops and later miniaturized for notebooks.

I also say this as the owner of a notebook with an i7 740QM/PM55 chipset in it and I'd rather have an Arrandale. At the end of the day, if I wanted nothing but speed, I wouldn't even buy a laptop since they are all inferior to a similarly priced desktop system anyway.

Nope, I bought a laptop so I could move around and carry my computer with me. I bought it so I could PC it up on the couch. I can't do that well if my notebook is slow cooking my nuts and thighs with 90 degree heat. I can't move around if I need to be plugged into a wall socket all the time because my cpu is addicted to current and won't acknowledge it has a problem every time it needs one more hit from the mains plug.

I don't have effective range outside my own house without the ability to turn off my nVidia graphics with Optimus. For a notebook I'd say these things matter more to me than speed and I regularly subject my notebook to workloads that can fully load down 4 cores (music production software and plugins).

 

multi core coresmark benchmark give the i7 720QM 11% faster which is quite close to 12.94% that you've found
which is quite confirmed with my tests with other multi threaded benchmarks like wprime, in a way passmark and others
but dual core coresmark benchmark gives the i7 620M 28.8% faster than the i7 720QM
so
If you intend to play chess or use some multi threaded demanding application then yes the i7 720QM and even better the i7 740QM are faster than the i7 620M for this

 

Yep, Clarksfield is exactly that, it's a cherrypicked Lynnfield (desktop i7-8x0 series).


Re cooking your nuts - get a notebook cooler! Even a yumcha $15 one where the fans bust after 3 months is enough to preserve airflow underneath the thing.

 

I already tried the freezer without succes
maybe adding a water cooling device inside the laptop or a trip to north pole could help getting a nice desktop cpu from the 9x0 serie then

 

Updated..I ended up buying an M11x refurb. (already have a powerful desktop and three other notebooks) I wanted something small to keep on my livingroom endtable. The M11X fit the Bill and the price for the thing after the 20% off coupon was slightly more than a decent netbook.

In any case I AM RUNNING GTA IV on it and it looks fine.Also running FSX on high settings. Maybe its the small screen that doesn't require the HP of a 5870 but this GT335 handles games well. I rendered a 30 Minute MPEG last night using Vegas on it in about 40 minutes. Multi track recording is a breeze.

The issue is when people get hung up on synthetic benchmarks. I am getting very playable locked 30FPS framerates. The thing probably doesn't benchmark worth a crap but it does well "in real life"

I am glad my initially ordered M17X and then M15X were RMAs. This guy does well and the battery life is an extra benefit using GMA graphics. When Sandy Bridge is released I will buy a new MB and upgrade my desktop.

 

That is quite surprising. What are the settings you run GTA IV in?
I am running GTA IV EFLC with all settings high(except no shadows which I figure makes a huge difference,view distance and detail distance at 50%) and must be getting avg. 38 fps or so. (Haven't benchmarked. But fps hovers around 40's-50's and goes down to 30's or 20's sometimes. My Lap has i7-720QM,ATI 5730M running @ 1366x768, the same res as Alienware M11x).

 

Some one is running GTA IV on the M11x and fine is subjective.

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After quite a bit of research I ordered the i7 620m. Sure at first the quad core seemed more desirable but I don't need the added risk of stuffing even more heat into my little system. Also the frequency is so much lower on the quads so in reality it would be quite a bit slower most of the time even in gaming. Saying that if I were building a new desktop quad would be a certain. But in a laptop? Nah I'll skip until they are really needed.

 

I have used both CPU's and there was no difference in gaming or emulation performance. However, with the Dual I couldn't play GTA IV without lowering every single setting and even then, I still had problems.

My mobile i7 820qm is equivalent to the newer mobile i7 720qm (i7 740qm) and you are looking at a clock rate difference of 2.8 Ghz on 2 Cores (Turbo Boost) for the i7 720qm Vs 3.06 Ghz on 2 Cores for the i7 620m (or i7 640m). Of course the Dual Core will give you a little less heat but in my laptop, I am idle at 44C anyway. I don't know if the new i7 640m has a slightly higher Dual Core Turbo Boost rate than 3.06 Ghz or not.

So for gaming the i7 720qm (i7 740qm) will not be slower than the i7 620m or i7 640m. If games are more CPU intensive, the speed difference between 2.8 Ghz and 3.06 Ghz on 2 Cores will be negligible and if a game is CPU intensive but uses 4 Cores or is poorly optimised then the newer i7 720qm mobile Quad could give you an advantage. I have found that the Hyperthreading of the Dual Core is no match for extra physical Cores.

If you have a well designed chassis in your laptop, there are no heat concerns with either CPU.

 

I've read the whole thread carefully enough to differentiate the applications of dual and quad core CPUs and to understand the advantages and disadvantages of both platforms. The question is, what if I want to do both hardcore gaming and audio/video editing? To state the obvious, the 9xxXM would be a match for both worlds, but let's keep the price level at 7xxQM...

Considering that the bottleneck for modern gaming should be the GPU rather then the CPU, would it be safe to say that, while the 620M seems better, the 720QM is good enough? Many of you refer to the 620M as fast dual core and to the 720QM as slow quad core, but is it really so? Isn't the 720QM just not as fast as the 620M in 1-2 core processes, but still fast as hell (with the Turbo Boost)?

The reason for my questions is that I'm looking to get a Dell XPS L701x. Here's the deal: Dell offers both dual and quad core CPUs, however, a dual core comes with 1GB GT 435M GPU, while a quad core comes with 3GB GT 445M GPU. Now, aside from the fact that these configuration limitations (no i5 with 445M) are quite irritating (to say the least), it seems to me that the designer intended to compensate the lower efficiency of the quad core in 1-2 core optimised games with a more efficient GPU. So asking the question in this context: will the quad core config perform in modern games as good as the dual core config with less GPU power? ...or will I still be likely to loose FPS due to lower clock speed, regardless of the GPU? And I mean considerable loss of FPS, not 99 -> 91 in some kind of benchmark...

 

the post above yours answers you question about gaming. also having a 720qm myself, id say you lose nothing since it is still a relatively fast dual core.
for audio/video editing there is no question that an i7 quad is so much better.
my suggestion, ask dell if the motherboard for all cpu models of the xpsl701 is compatible with extreme cpus. if they are, buy the cheapest i3, and buy an es/qs 920xm on ebay which you could net at around 380usd.
however, also check the dell forums to find out wether the dell can handle the thermal loads of an 920xm ( i think it should do just fine).

 

You're right, LaptopNut made the point I had on my mind, but I just couldn't help emphasizing the questions, which lead me to this thread.

Also, in terms of running 1-2 core GPU-oriented processes (aka games), I was hoping for some thoughts on getting a lower clocked CPU and a faster GPU in regard to Dell's offer. Speaking of which, I decided to go with a 740QM, as it comes with a better GPU and additional two DDR3 slots. Well, I guess I've gone a bit off the topic...

Lastly, in terms of heat and power consumption, does any know whether the quads are able to shut down 2 or 3 cores, when not Turbo Boosting? Either when idling or when running light single-core processes? I'm having trouble finding any details about clock speeds in regard to SpeedStep and Turbo Boost. Intel's ARK seems to mention only base and max speeds.

 

With the mobile i7 CPU's, Windows 7 will park Cores that aren't in demand. If you take a look at the Core parking and CPU usage in the Windows 7 Resource Monitor, you will see a total of 8 Cpu's due to the hyperthreading which can be confusing if you are new to it.

Even when you do play a GPU intensive Dual Core game, another Core is likely to be dedicated to background Operating System tasks though.

 

Ah, core parking - that's exactly what I was thinking about, just never came across it before.

On the other hand, there's a whole thread on "fixing" this feature, as its behavior seems far from ideal. According to the fix description, it's possible to define the minimum and maximum number of parked cores per power profile in Windows (via regedit). I suppose this could be used to allow the machine to run on all four cores constantly (with no parking at all), when plugged into AC, and to limit it to use only two or even just one core (with lot's of room for Turbo Boost), when running on battery. Adding to such custom power profiles adequate SpeedStep settings (either via regedit or via cmd -> powercfg) should provide a precise way of controlling the quad core's performance and power consumption.

Achieving all this in Ubuntu (which is my primary OS) is another story... I'll explore it once I get my hands on that quad...

 

youd could also set the number of processors via the advanced tab in the system configuration utility:boot.
i used this option when i ran into conflicts with this certain program (which has been updated to support multicores now).

 

Well, it certainly does the job too, but it's not as convenient, as it requires reboot to take effect. On the other hand, it may be more stable/effective.

The problem with both ways is that - with HT - the system doesn't exactly describe physical cores, so by leaving 2 out of 8 logical cores I would expect to have only one physical core in use, while the system might as well use two physical cores - one logical per each physical. I'm sure there are ways of testing this. And I may be confusing something...

 

There are 2 logical cores per physical core, not one logical and one physical. People get confused. The two threads for each core are called "logical cores" because it sounds better.