Which Processor on XPS 1647?

I've been stalking the XPS 1645/1647 for a while now hoping that the overheating/under clocking issues get resolved. I'm to the point now where I just need to roll the dice and make one of these work for me.

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Currently I work off of a Mac Book Pro (latest unibody) with the 3.06 GHz processor upgrade and the 256 SSD upgrade and 4GB RAM. I do primarily web design (.NET, WordPress, etc.), so I stay in Windows (via Bootcamp) most of the time or work on my Sony Vaio Z. I was waiting for the Bootcamp upgrade to come out in hopes that it would help the hardware cope with Win7 better. Well, it came out a couple of days ago, and it did help, but it's still lacking in a few ways.
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My question is around the processor. My everyday activities, making up 80% of my day, are fairly light with the exception of Adobe Creative Suite apps and Microsoft Visual Studio, but I do a decent amount of video processing. I am looking for the most power available without sacrificing battery life. If I understand the processor options correctly, that would be the i7-620M. How would that processor compare to the i5 540M in terms of speed and battery life? I have read that the i5 is "newer technology" and "should" be more efficient than the i7's.

Any help is appreciated.

-brit

 

If I understand correctly, the i7 you cite (i7-620M) is really more like a faster (duel core) i5 being marketed like an i7 (due to it's greater processing speed). All the other older i7s are quad core models, while this new i7-620M is a duel core model. I believe that this new i7-620M is the same fab generation as the current crop of i5s. I haven't confirmed this myself, but I think I read that the older i7s were 45 watt parts, while the newer i5s are 35 watt parts. If this is the case, I'd expert this new "i7-620M" to be a 35 watt part (since it really is just a faster clocked duel core i5 with a little bit more cache). You could probably find more specific wattage info on intel's own web page.

 

Oh, great. And my confusion continues. ;-)

Thanks for the information. I would really like to find some real world tests of these different models (or at least other brands/models with similar processors), but there doesn't seem to be much available yet.

Thanks for the information.

 

QuadSk8er is right, the i5 are a totally different architecture from the previous i7's think of them as a replacement for the Core2Duo line. The i7620 is more like an i5 than i7 really. The i5 should meet your performance needs but what you do mean by video processing? You were right in assuming that the i5 would give you better battery life as well.

 

You should get the 520. The main advantages to the i5 for you is SSE4.2 instructions. Clock speed (the .13GHz and .26GHz difference compared to the 540 and 620, respectively) aren't enough to change the speed at which you work, substantially, but the power consumption is enough to noticeably change your battery life.

 

I use Adobe Premiere often for video editing. I have a quad core desktop that I use for longer productions (DVD's, etc.), but often I need to do shorter videos on the laptop. So far, the MacBook has been fast enough, so I'm thinking that the i5 should be at least as fast as the MacBook, if not a little faster.

Thanks for the feedback on the 520.


-brit

 

I use Sony Vegas they are about equal in system requirements. The i5 should be fine, and the dual core i7 doesn't offer a huge boost so you should stick with that.

 

Thanks for the suggestion.

I notice in your signature that you're sporting an i7. Have you had any hands on experience with the i5's?


thanks,
-brit

 

No I haven't but I have looked into intel's new i5 and i3 processors. I prefer quad-core due to future proofing and I don't care too much about battery life, which was one of your concerns. The i7 you mentioned though (620) is a dual-core like the i5.

 

Notebookcheck has both new i5 and i7 benchmark.

http://www.notebookcheck.net/Mobile-Processors-Benchmarklist.2436.0.html

 

Based on those charts, I was characterize the 520 as roughly equivalent, and possibly a touch worse than your C2D. The 540 is a definite step up in terms of performance, but quite a minor one. Also, you're likely to see better performance on either the 520/540 than you would expect from the benchmarks because the i5s support additional SSE instructions, which subsequent versions of your encoding software will no doubt support, which will grant rather big improvements.

All in all, I don't see a compelling reason to upgrade from that C2D. If you want to, know that you'll be doing it primarily in order to get the i5 µarch and the accompanying SSE instructions. It won't feel any different in normal usage. Because of this, I do still recommend the 520.

 

If you look at individual column, 520m is actually better than c2d in most columns.

 

Not his. Please compare it to the stats of the 3.06GHz C2D.

 

Thanks for the spot-on information. I really appreciate it.

Originally, probably as many others have, I assumed all of the i7's were quad core, so I expected a relatively large increase in performance during encoding and editing over my current C2D. Seeing that the later i7's are dual core, it makes my predicament a little different.

I'm probably not going to go out and buy a $2600 laptop for a mere marginal increase in performance and probably shorter battery life as compared to the MacBook. So, now the question changes a little. Should I go with a quad core i7? It's probably either that or stay with what I have. The new Bootcamp (v3.1) at least makes the trackpad usable in Win7 on the MacBook. It's not perfect, but at least usable.

The faster FSB, higher clock speed, additional 4GB of RAM (8GB total) should make for a much better experience during heavy use, albeit causing more heat and shorter battery life versus the MacBook.

Decisions. Decisions.


-b

 

The i7 (quad) is great for editing/encoding video which is one of your intended uses right? As I'm sure you already know you're trading battery life for that extra power. The benefit of the i5 vs your c2d are mostly hyperthreading and turbo boost, hyperthreading is useful for editing and tasks like that.

I think the performance boost with an i5 is a little bit greater than most people are stating due to the fact that single threaded applications will run so much better with turbo-boost and you get the benefit of 4 threads vs 2 in a multi threaded app. The same goes for the i7 but the difference is even greater (8 threads vs 2)

 

Yeah, that makes sense. Thanks again for the insight.

 

So when do you all think they will move to 32 nm quad core i7s (or better) for laptops?

 

No time soon probably, I don't remember seeing anything like that on the roadmap.

 

Is the 1647 using the same 1333MHz DDR3 memory that is offered on the 1645? The Dell website doesn't list the DDR3 memory speed for the 1647.

 

Don't forget about switcahble raphics too.

As far as I've read about it both i7 620 and i5 CPUs have integrated graphics, though I think I remember reading something about the motherboard that the i7 620 DELL models come with dosen't support this switching option, if true the i7 620m model wuold be running the HD4670 all the time, consuming more, while if the i5 models let you turn off the HD4670 you'd definately gain longer battery life.

BTW how much power does the i7 620m consume than the i5 CPUs? I thought they don't have that much of a difference.

 

Neither of them support switchable graphics. The Arrandale Core i7's are very similar to the (Arrandale) Core i5's. As both share the same TDP, the Core i7 620M shouldn't be significantly more power consuming.

Based on your needs and interest in switchable graphics, it may not be bad to take a look at the Asus N61JA-A1 if you don't mind the resolution. It has a weaker CPU but includes a better GPU, switchable graphics, and USB 3.0 support not to mention a Blu-ray player (though I'm not sure this matters to you).

 

All Arrandale CPU's support switchable graphics. The limiting factors however are the chipsets used (e.g. HM55 supports, PM55 does not) and whether the dedicated GPU has drivers that support "turning off".

As you have mentioned, the Arrandale Core i7's are more similar to the i5's than they are their big brother i7's. However, Dell still use the PM55 "performance" chipset with the i7 models; regardless if the i7's are Arrandale or Clarksfield. They use the HM55 "mainstream" chipset with the i5's, thus enabling switchable graphics support.

Also, ATi's latest graphics drivers support switchable graphics for the HD 4670. So, there's absolutely no reason why a SXPS 16 with a i5 processor, HM55 chipset and a HD 4670 wouldn't support switchable graphics. I'm surprised we don't have any i5 SXPS 16 owners on here yet, or does anyone know of any? If we had, it would clear up all this confusion!

 

That is correct. I intended to refer to varying Dell configurations of the SXPS 1647 (and 1645) but that was unclear in my post.

Are we sure they don't use HM55 on Arrandale Core i7's and it isn't simply marketing failure? I mean the Arrandale Core i7's aren't much much better performers yet aren't a cheap upgrade ($120 for 1MB of L2 cache and a 100MHz clock speed increase per core on multi-thread optimized applications). The lack of switchable graphics makes the Core i7 options on the SXPS 1647 worse in my mind (I would actually consider paying a small amount to downgrade from a 620M to a 540M).

Weren't there already some Bestbuy model viewers/owners around these forums?

 

Ah, I see. Well we know the 1645 variants don't but as I mentioned before in another thread, there's no reason why an Arrandale/HM55/4670 shouldn't support switchable graphics. One member here suggested that Dell haven't enabled it through the BIOS yet, and another suggested that a physical connection to the monitor from the IGP may not exist yet. Either way, I want to get talking an SXPS i5 owner to find out for sure!

Unfortunately not. A i7-620M owner confirmed here, that his SXPS 16 was shipped with the PM55 chipset, unfortunately ruining the possibility for him of using switchable graphics in the future. I agree, it doesn't make sense. The i7-620M (being an Arrandale CPU) is more similar to the i5's than it is the other i7's, so it should ship with the HM55. But, I have a feeling just because it's an i 7, that's why it ships with a PM55, like the other i7's. I hope it changes TBH.

The hunt is on!