i7-720QM vs. i7-840QM -- video productions

Hi all,

I'm about to order a new HP Envy 17 3D. The only decision I'm struggling with is with which CPU, i7-720QM or i7-840QM?

My main work with this laptop will be the production of educational and instructional videos (slide show & live videos). That means I'm going to be encoding stuff and working with numerous applications on a regular basis such as After Effects CS5 (64bit), Photoshop CS5 (64bit), Premiere CS5 (64bit), Audition 3, Fireworks, Camtasia, Captivate, etc etc.

Do you guys know if there will be a substantial gain in speed if I spend $400 more and get an i7-840QM vs. an i7-720QM?

As one example, if the i7-720QM would spend 60 minutes to encode a video, approximately how much faster (if at all) would the i7-840QM encode the same video?

Thanks much for any insights you might have.

 

I would honestly wait for SB, you'll be able to get faster for the same money by waiting for an SB model.

If there was just a 50-100 dollar difference, I would go for the 840QM, but for 400, it's not worth it. You can get a 920XM for that much + 100 bucks.

 

Unless you're getting a significant savings if you can wait a month or so they most likely will have an Envy with the new Sandy Bridge CPU's which are far and above more powerful then existing i7 series CPU's. The i7-2720QM should outperform the 920XM at significantly less cost too.

edit: dang. ninja'd!

 

The difference between the 720QM and 840QM is not worth $400. That said, since you are working with all of these CPU-intensive applications, I would strongly recommend buying a laptop with one of the new Sandy Bridge CPUs. It is much faster than either of those two processors -- often by nearly a factor of 2, almost always by at least 50%.

 

I thought HP had SB CPUs out.

There's isn't a 3rd option? i7-740Q ?

*EDIT* I say ditch the 3d, and use those couple hundred dollars for the 840Q chip

 

They do but I don't think Envys have been refreshed yet, or been announced for new models. I thought he may want to stick with Envy.

The 740QM isn't really worth the upgrade over the 720QM, unless it's sub 100 dollars. Difference is 130 Mhz plus the turbo..

 

Sorry I did an edit before I saw your post

 

I agree with waiting for SB. Even the low-end 2630QM outperforms both CPUs.

 

@ htwingnut -- Unfortunately, can't wait... gotta order now.

@ Althernai -- Thanks for the link with the charts! My current laptop's CPU is a tad slower than the P520 in those charts, so it's nice to see how much of an increase in speed I'm about to experience.

@ alexmuw -- Yes, there is. The i7-740QM would cost $100 more than the i7-720QM...

 

This is ridiculous -- Intel sells these two for exactly the same price and the only difference between them is the smallest possible increase in clock speed.

BTW, if you absolutely cannot wait another few weeks, there are already some Sandy Bridge laptops out now (although depending on what you like about the Envy, it's not clear whether they'll satisfy you).

 

My advice: Get the cheapest CPU and buy a 920xm from ebay (about 400$)
Then use throttlestop to realease the beast You should be able to run it at 3.2Ghz across all cores (instead of only one with the standard turbo boost) as long as the cooling system isn't crap.

This will even beat the Sandybridge 2720QM as far as I know...

 

I agree that's a bit much. My understanding was that the 740 was supposed to replace the 720 (I assumed any laptop with a 720 chip was outdated).

Like Althernai said, if you want a SB, might have to look at other manufacturers (though I think the Pavilion has SB chips).

 

Depends on cooling. The 2720QM could probably maintain a steady 2.7-2.8GHz on four cores in well-cooled notebook. (Max is 3.0GHz.) At that level, the difference becomes negligible.

 

Thanks very much for the great tips so far!

So the $400 aren't worth it, fine, and buying a laptop with a SB would be even better as it would increase speed significantly.

I'm currently researching and assessing laptops with SB vs. the HP Envy 17 3D.

 

Max of a 2720QM is 3.3Ghz (Turbo boost, on one core)
I really don't think that it will be possible to adjust the multi of the non extreme processors... so no 2.7-2.8GHz on four cores for this SB CPU.

2.2 GHz vs 3.2GHz on all cores (assuming the laptop has a decent cooling system) is not negligible imo.

 

Well, SB is more efficient. Certainly an Extreme CPU will be more powerful with a significant overclock, but the point is that there will be even more powerful options later.

 

I was talking about Turbo Boost. 3.3GHz is the max for one core, 3.2GHz is the max for two cores, 3.1GHz is the max for three cores, and 3.0GHz is the max for four cores. Intel has REALLY improved Turbo Boost this time around.

http://www.anandtech.com/show/4084/intels-sandy-bridge-upheaval-in-the-mobile-landscape

 

Oh well... impressive! Thanks for the info! However I wonder whether you will actually get more turbo boost... my experience with the first gen i7 is that you rarely get turbo boost, and always never the max turbo boost.

Usually the cpu will just lower the multi really fast to the standard clock because of the fixed TDP/TDC limits.

Hope you get more Turbo Boost with the new generation.


I agree, when working on the go is important, SB will probably be a good choice, however as the OP thinks about getting a 17 inch system, I don't think he will carry it around all the time.


Thanks again for the info, City Pig! New tech like SB is always great, but sometimes I think it's just to much of a hype.

 

Well, that's the thing. It can only stay at max for 25 seconds at a time because it needs to exceed the TDP to do so. Otherwise, if the CPU still benefits from boosting, it tries to stay at the highest point within in it's thermal limits after the 25 seconds, but it does fluctuate. So, for gaming at least, it's probably at least at about 2.5GHz most of the time. That still makes the extreme better, but it still stays much hotter than a 2720QM that whole time. For video editing and encoding, however, it probably tries to stay higher. At 2.7-2.8GHz, it would be on par with a 3.2GHz Nahalem.

 

That's the thing. I'm not doing overclocking or stuff like that, never did and never was fond of such artistic things. Plus, I'll likely not play games with it other than a quick Hearts or Mahjong Titans to relax or distract my brain for a couple minutes. ;-)

I just want a quality laptop for the next 18-24 months, one that performs my day-to-day video related tasks faster than the old one. Then in 18 or so months I'll buy a new one again which will be better and faster than the one I bought 18 or so months ago, and on it goes.

The significant difference in speed and power management between, say, an i7-720QM and an i7-2630QM, while the price difference seems to be trivial, caught me by surprise. So I'm digging into this stuff right now...

And yes, 17" is the minimum, as well as 8 GB of RAM (hopefully more) as I often have 3 - 6 heavy apps running at the same time.

 

For RAM not sure what AW pricing is, but if it has four RAM slots, you can get 8GB DDR3 1333 for ~$90. So in other words, buy your own, as I have a feeling AW might charge significantly more.

 

4 slots. He is/was looking at a HP Envy, although if he's looking at SB, I'm not sure what he's looking at.

 

It depends on the cooling, but the machine reviewed so far (an early Compal sample that will not be sold) stabilizes at halfway between min and max. The first gen mobile i7 (Clarksfield -- the 720, 740, 820, 920, etc.) are very different from the second mobile generation (Arrandale) and even more different from Sandy Bridge. The problem with Clarksfield is that Nehalem (which it was based on) was an architecture intended for servers -- the TDP was initially not less than 130W. Since Clarksfield and Nehalem were both 45nm parts, Intel could not die shrink the heat away (that wouldn't happen until Arrandale), but they had promised new CPUs so they had to do something.

The result were these hot, power hungry CPUs that ran at low clock speeds and just barely outperformed the mobile Core 2 Quads. It's not really surprising that you rarely get Turbo with Clarksfield -- they run hot even at base frequencies. Intel got away with it because it has no real competition at the high end and, despite the drawbacks, they were still more powerful than anything else out there at the time. You can overclock the unlocked ones into relevance, but honestly, it's almost like overclocking a P4.

To some extent yes, but if you're going to do CPU heavy tasks, the hype is definitely warranted. It's the first CPU since Core 2 that is close to its desktop kin and the performance increase from Clarksfield is massive (to a considerable extent because Clarksfield was not very good to begin with).

 

Great info, Althernai, thank you very much!

So that explains why Clarksfield notebooks get so darmn hot, doesn't it?