FRIHOSTFORUMSSEARCHFAQTOSBLOGSCOMPETITIONS
You are invited to Log in or Register a free Frihost Account!


Need some advice on Intel CPUs; which to pick?





quex
Hey again. Very Happy

So thanks to some excellent suggestions and patient explanations in this thread, I am now tasked with deciding the final specs for a college kid's first laptop. She is hooked on the idea of a Dell Studio 15, and we've got all the little crap (software, battery, color, etc.) figured out. The big hangup right now is the damn processor... because I have no idea how these damn Intel i3/i5/i7 things work, nor any understanding of the advances made since dual-core processors. Quad core? Hyper-threading? What is all of this? -_-;

My entire knowledge of processors is summarily thus: higher GHz is faster, "duo" means 2 cores in one processor, cache should be 2MB minimum, and always pack the machine with all the RAM you can. Keeping in mind that the system we're building will use Windows 7 and may have to run AutoCAD but will not be a gaming machine, what I'd really love to know is:

1) What is the actual advantage of the iTypes (i5 and it's family)? I understand that they are supposed to overclock themselves internally, but what, if any is the real superiority of having a CPU that can reach 2.66 in turbo mode, vs. an older CPU that was built to reach 2.66 normally?

2) Would any iteration of a Core 2 Duo processor be preferable compared to an i5, in terms of performance and stability, if not price?

3) Is there a good explanation of modern CPUs anywhere on the web that any of you fine folks could share with me...? I'm completely lost these days. ;_;

Please oh please oh please help my ignorant a** out with this, and thank you so very much. Laughing
mOrpheuS
quex wrote:
1) What is the actual advantage of the iTypes (i5 and it's family)? I understand that they are supposed to overclock themselves internally, but what, if any is the real superiority of having a CPU that can reach 2.66 in turbo mode, vs. an older CPU that was built to reach 2.66 normally?

Core 2 Duo/Quad are based on "Core/Penryn" architecture.
Core i3/5/7 are based on "Nehalem" architecture. The two are not comparable clock-for-clock.

Here's a list of improvements in "Nehalem".
And another good article on the architecture.

quex wrote:
2) Would any iteration of a Core 2 Duo processor be preferable compared to an i5, in terms of performance and stability, if not price?

For similar clock speeds - No ... unless you're getting a great deal on the core 2 duo.
quex
mOrpheuS wrote:

Core 2 Duo/Quad are based on "Core/Penryn" architecture.
Core i3/5/7 are based on "Nehalem" architecture. The two are not comparable clock-for-clock.


Snapdamn, that's awesome. The links help tremendously. Although I'm still a little slow in the head about the intricacy's of Nehalem architecture, I can spot the differences between many of those visual layouts for Penryn vs. Nehalem, and the author comments clear things up about where the advances have been made. Thank you very much, sir.

I was trying to figure out the lineup of processors in the i# series, (since Dell's ordering process presents them as such and seems to line them up as different strengths of the same product), and came across this article, suggesting the Core i5 750 is the sweet spot. It was written in September of '09, however, and I'd assume there have been some tweaks since then. Do you (in all your expertise, and I mean that sincerely and without any snark), agree with the backdated article's assessment of the i5 750's value, or would you suggest a different configuration...? (And thank you, again.)
mOrpheuS
quex wrote:
I was trying to figure out the lineup of processors in the i# series, (since Dell's ordering process presents them as such and seems to line them up as different strengths of the same product), and came across this article, suggesting the Core i5 750 is the sweet spot. It was written in September of '09, however, and I'd assume there have been some tweaks since then. Do you (in all your expertise, and I mean that sincerely and without any snark), agree with the backdated article's assessment of the i5 750's value, or would you suggest a different configuration...? (And thank you, again.)

Yes, until the next "tick" from Intel (or an unlikely surprise from AMD) the assessment is just as valid now as it was when the article was written.

The i5 750 is essentially the same as the i7 860 (with a slightly lower clock speed and hyperthreading disabled). It is very good value for money indeed.


I got an i7 860 myself instead for the following reasons -

1. In most benchmarks, the 860 performs very similar to the 920/930 (they are also very similarly priced) and better than the i5 750 (especially in the multi-threaded benchmarks) -
http://www.anandtech.com/show/2839/2
http://www.guru3d.com/article/core-i5-750-core-i7-860-870-processor-review-test/12

2. The 860 runs on 1156 socket which translates to cheaper motherboard and memory compared to the 1366 socket, on which the 920/930 run.

3. The i5 750 wasn't as cheap at my place at that time.
My place (at that time) ... "i5 750" -> $235, "i7 860" -> $300 (Difference of 22%)
US (Now) ... "i5 750" -> $195, "i7 860" -> $290 (Difference of 33%)

Given its price now, the i5 750 is a very good choice for a medium budget.
quex
Well, crap. I guess I jumped the gun a little; I assumed Dell would have a wider range of cpu choices available on the model my sister (the college kid in question) has fallen in love with, but for reasons probably related to the size of the machine and the cooling system therein, we're limited to the following: i5 450, i5 520, i7 720, or i7 820. Crap.

If this were a homebuild, I'd have to agree with your choice of the i7 860... but, unfortunately, we don't have enough time (or skill, on my part) to make that an option by the start of first-semester. For the prices Dell is asking, I'm right between the i5 520 and the i7 720... but their site doesn't make it very easy to figure the actual cost. >,o GRRRR. I'd estimate it's about a $200 to $250 difference in price.

Here's all they'll tell me:

NEW 2010 Intel® Core™ i7-720QM Quad Core Processor 1.6GHz (2.8GHz Turbo Mode, 6MB Cache)
vs.
NEW 2010 Intel® Core™ i5-520M 240GHz (2.93Ghz Turbo Mode, 3M cache)

As I mentioned, quad cores are new to me. It sounds like a considerable advantage, especially paying attention to the cache size, but my brain keeps looking at that 2.8GHz vs the 2.93GHz and I get confused. Does the quad core mean you can literally multiply the base speed by four (1.6 by 4 = 6.4GHz)? Or simply that there are truly 4 simultaneous processing functions, each available to handle different tasks with 1.6GHz, or 2.8GHz at "turbo" mode (which I assume is hyperthreading)?

Unless I can get something customized at Dell to include the i5-750, or unless you warn me otherwise, I think we're going to have to settle for the i5-520... in which case, would increasing the RAM to the maximum 8GB give a significant advantage to the lesser processor?

And lastly, where do you shop for your RAM cards? <:)

Thank you again, and very much. I really do appreciate everything you're telling me.
william
Quick point, the i5 750 and i7 860 are desktop processors. The Studio 15 has mobile versions. To answer your questions:

1. Alright, so to start off, Intel markets the i3 as the entry level lineup, the i5 as the midrange, and the i7 as the high end. Both the i5 and the i7 have Turbo Boost, the i3 doesn't. The i3 and the i5 are all dual cores while the i7 is available as duals and quads (hexa on the desktop versions as well). Now, here's where things start to get fuzzy. With some of the dual core i7s and and i5s, the performance often overlaps, with the i7 being a slightly better performer but at a much higher price and with potentially less battery life. So at this point, you'd have to compare specific CPU models to reach a verdict.

Oh, and Turbo Boost. I'll use some arbritrary numbers for this, but hopefully this will explain it. These CPUs have multiple speeds they can run at. Let's say it's a quad core 2.66 GHz CPU that boosts to 3.2 GHz. When you're doing normal, single threaded, tasks, only one core will run and it can run up to 3.2 GHz. Once something multithreaded comes in, with two threads, it will enable a second core and the speed will max out at 3.06 GHz. Then once you start having even more threads, all cores can enable and run up to 2.66 GHz. Basically, if only one core is running, it has enough thermal headroom to reach higher speeds. Enable all of them, and throttles down to it's normal speed. So if a CPU can reach 2.66 GHz in turbo mode, it would only reach that speed using one core, in contrast to a 2.66 GHz "normal" CPU which will be running at that speed with all cores.

And hyperthreading is something Intel had back in the Pentium 4 days. It's a method that duplicates sections of the CPU that store the architectural state without duplicating the execution resources. In essence, it creates two virtual (logical) cores in one normal core. Intel claims 30% performance increases, and at least with the Pentium 4s, that was a reasonable claim. I'm not 100% sure how useful it is with the new chips, but I'm sure it's at least noticeable.

2. Other than price, not really. The new lineup is both faster and more efficient than the older Core 2 Duos, however some of the higher end Core 2 Duos can nearly match the new lineup. But all in all, no need to go back to Core 2 Duos unless you want to save money.

3. If you want plain old benchmarks, try this. Word of advice, it's not always the most reliable site, but it should give you an idea. Also, the top of the list is dominated by desktop processors which are only found on Clevo D900F. Specification comparisons are here. Weirdly, I haven't seen a good explanation of all of the current CPUs in one article yet. Confused The latest ones that I've found are from the late Core 2 Duo era. Tom's Hardware and The Tech Report have some decent articles for the i3/i5 and the i7, though.

For the Studio 15, I would personally go for the cheapest quad core i7, but I'm also a power user. It depends on your budget and whether or not you want 4 cores, Virtualization Technology (ability to run multiple OSes and use Windows 7's XP mode), Turbo Boost, AES, etc. Based on your needs, an i5 or the i7-720QM are your best bets, IMHO.

Edit: Bleh, didn't read your latest post. (Was typing as you posted. Razz ) Will update this post shortly.

Update:

When you have a 1.6 GHz quad, it's 4 threads each running at 1.6 GHz, not 1.6 GHz x 4 = 6.4 GHz.

Between the i5-520M and the i7-720QM, well, that's the most common comparison I see with notebook CPUs, the usual dual vs. quad. In single threaded tasks, the i5 is slightly faster, but that's often negated in mathematical and data intense programs due to the i7's greater cache. The multitasking abilities of the i7 are much greater and the single threading is about the same as the i5. What the i7 really suffers from is power consumption and heat output. I can't find the chart right now, but it's an scenario. Comparing the i5s and the i7s, the performance graph is relativly constant, but the the power consumption skyrockets when you get up to the i7. Under load, the i7 will run a lot hotter and eat the battery faster. Price/performance, the i5 520M is probably the better choice, especially considering under normal usage, the performance difference is unnoticeable against the i7.

Also, I do recall reading a couple of things about the i5-450M, and how it might perform as well as the the i5-520M. I'll look into that, but so far as I recall, that's not a bad option at all if you don't need some of the 520's features, like virtualization.

As for RAM, day to day tasks are just fine with 4 GB. Going up to 8 GB won't make a huge difference unless you're doing some massive design work. But as always, you can save money by buying RAM seperately, in which case Newegg is a great place to buy RAM.
quex
william wrote:
Quick point, the i5 750 and i7 860 are desktop processors. The Studio 15 has mobile versions.


OH. Well, then. That explains things... I was thinking it has something to do with that... I guess that means there are processors so hot that you can't wrangle them into a laptop anymore?

Quote:
To answer your questions:

1. Alright, so to start off, Intel markets the i3 as the entry level lineup, the i5 as the midrange, and the i7 as the high end. Both the i5 and the i7 have Turbo Boost, the i3 doesn't.


I was under the impression that only the i5-750 had turbo boost...? Probably incomplete info from Dell's crappy site, I suppose.

Quote:
The i3 and the i5 are all dual cores while the i7 is available as duals and quads (hexa on the desktop versions as well). Now, here's where things start to get fuzzy. With some of the dual core i7s and and i5s, the performance often overlaps, with the i7 being a slightly better performer but at a much higher price and with potentially less battery life. So at this point, you'd have to compare specific CPU models to reach a verdict.


Aha, I was expecting something like that... always seems to happen with Intel.

Quote:
Oh, and Turbo Boost. I'll use some arbritrary numbers for this, but hopefully this will explain it. These CPUs have multiple speeds they can run at. Let's say it's a quad core 2.66 GHz CPU that boosts to 3.2 GHz. When you're doing normal, single threaded, tasks, only one core will run and it can run up to 3.2 GHz. Once something multithreaded comes in, with two threads, it will enable a second core and the speed will max out at 3.06 GHz. Then once you start having even more threads, all cores can enable and run up to 2.66 GHz. Basically, if only one core is running, it has enough thermal headroom to reach higher speeds. Enable all of them, and throttles down to it's normal speed. So if a CPU can reach 2.66 GHz in turbo mode, it would only reach that speed using one core, in contrast to a 2.66 GHz "normal" CPU which will be running at that speed with all cores.


GOT IT. Killer explanation! You sound like you teach this stuff. XD

Quote:
And hyperthreading is something Intel had back in the Pentium 4 days. It's a method that duplicates sections of the CPU that store the architectural state without duplicating the execution resources. In essence, it creates two virtual (logical) cores in one normal core. Intel claims 30% performance increases, and at least with the Pentium 4s, that was a reasonable claim. I'm not 100% sure how useful it is with the new chips, but I'm sure it's at least noticeable.


I didn't know it went all the way back to the Pentium 4's, but yeah, a lot of what I found online seems to have the same opinion, that being hyper-threading capable is not half as important as the numbers defining the actual processor.

Quote:
2. Other than price, not really. The new lineup is both faster and more efficient than the older Core 2 Duos, however some of the higher end Core 2 Duos can nearly match the new lineup. But all in all, no need to go back to Core 2 Duos unless you want to save money.


Well, saving money is always nice, but I'm a sucker for efficiency and simplicity; if Dell is installing iTypes, best to just get an iType.

Quote:
3. If you want plain old benchmarks, try this. Word of advice, it's not always the most reliable site, but it should give you an idea. Also, the top of the list is dominated by desktop processors which are only found on Clevo D900F. Specification comparisons are here. Weirdly, I haven't seen a good explanation of all of the current CPUs in one article yet. Confused The latest ones that I've found are from the late Core 2 Duo era. Tom's Hardware and The Tech Report have some decent articles for the i3/i5 and the i7, though.


Thanks! I think I can tread water through a few of these articles, but my overall understanding of modern processors and their configurations is still far too lacking. -_-; Never hurts to have more information, though. I'm getting smarter from the simplifications you (and mOrpheuS) are so kindly providing - thank you!

Quote:
For the Studio 15, I would personally go for the cheapest quad core i7, but I'm also a power user. It depends on your budget and whether or not you want 4 cores, Virtualization Technology (ability to run multiple OSes and use Windows 7's XP mode), Turbo Boost, AES, etc. Based on your needs, an i5 or the i7-720QM are your best bets, IMHO.


We're going to get stuck with one of Win7's "home" editions, which don't provide XP mode if I'm not mistaken... and the kid doesn't know how to use multiple OS's except through BootCamp on my Mac. I'm thinking this will be mostly a machine for write-ups, internet goofing-off, and the occasional there-aren't-any-lab-machines-open-and-I-need-to-use-AutoCAD situation. (The third one is the one I'm hoping to patch up with improved RAM. :B)


Quote:
Edit: Bleh, didn't read your latest post. (Was typing as you posted. Razz ) Will update this post shortly.


I do that all the time. XD

Quote:
When you have a 1.6 GHz quad, it's 4 threads each running at 1.6 GHz, not 1.6 GHz x 4 = 6.4 GHz.


Understood. *nod*

Quote:
Between the i5-520M and the i7-720QM, well, that's the most common comparison I see with notebook CPUs, the usual dual vs. quad. In single threaded tasks, the i5 is slightly faster, but that's often negated in mathematical and data intense programs due to the i7's greater cache. The multitasking abilities of the i7 are much greater and the single threading is about the same as the i5. What the i7 really suffers from is power consumption and heat output. I can't find the chart right now, but it's an scenario. Comparing the i5s and the i7s, the performance graph is relativly constant, but the the power consumption skyrockets when you get up to the i7. Under load, the i7 will run a lot hotter and eat the battery faster. Price/performance, the i5 520M is probably the better choice, especially considering under normal usage, the performance difference is unnoticeable against the i7.


This. Decision made. Hot laptop = immediate, real-world problem, both on one's lap and in one's confidence that the components won't fry. Your comparison also gives me confidence that the less powerful CPU will meet 98% of all possible undergrad challenges.

Quote:
Also, I do recall reading a couple of things about the i5-450M, and how it might perform as well as the the i5-520M. I'll look into that, but so far as I recall, that's not a bad option at all if you don't need some of the 520's features, like virtualization.


Good to know; my father might be looking for his own new machine someday soon. (He pilots a dinosaur; 8 years old and counting.)

Quote:
As for RAM, day to day tasks are just fine with 4 GB. Going up to 8 GB won't make a huge difference unless you're doing some massive design work. But as always, you can save money by buying RAM seperately, in which case Newegg is a great place to buy RAM.


Hmm... really? My own machine is 2GB, so I'm pretty out of date. I was told that Win7 was an offensive eater of both speed and memory, and as such, so try and edge up the RAM to roughly twice whatever the laptop manufacturer gave as their minimum (which ends up being 3GB for the Studio 15). Maybe buy the 4GB option and add a 2GB card from Newegg later... I'll just see what's the best value for the final cost. (I am a bad cheapskate, lol.) Laughing

THANK YOU A TON. MOrpheuS too! I owe you guys for serious. If there's ever anything you need translated into Japanese, call me up. m(-_-)m
jwellsy
Intel has their head up their marketing butts on these cpu's. The way they sequenced their development and release was not very logical. I'm just saying it is very confusing.

Notice that these cpu's don't list a front side buss speed, that's because they now have internal memory controllers and don't have a front side buss.

The best thing about these new cpu's is that they use DDR3 ram.
william
Oh, that reminds me. Since she's doing AutoCAD, I would spring for the ATI Radeon HD 5470. The integrated chip is fine for 2D, but once you get up to 3D, having a dedicated card is a good idea.

As for the desktop chips, today there's really only one notebook that'll take it, but of course it weights 12 pounds and has an hour of battery life. Razz

Since you're getting Windows 7 Home Premium and won't need virtualization, then you may be able to spring for an i5-450M. I will try and find the article, but the performance is about the same as the i5-520M, but it's a fair bit cheaper, mostly because it's missing some features. Might be something to look into.

Windows 7 does eat RAM a lot more than Windows XP, but I really haven't found any major problems with 4 GB of RAM for typical use. If you need more, then I would agree that getting less RAM from Dell and buying a stick off Newegg will be a better deal. They [Dell] will give you two sticks though, so if you go that route, you will have to remove one. Perhaps buy 3 GB from Dell and upgrade it yourself to 6 GB (removing one 1 GB stick)?

Oh, and always with Dell, be on the lookout for coupons and deals. You'll save a lot in doing so. The last person I know who bought a Studio 15 got a ~$1200 configuration for ~$800. Also, right now I believe the Bing cashback for Dell Home is 10%.

All in all though, an i5 and an HD 5470 with a healthy amount of RAM will easily handle just about every day to day task you throw at it along with much more demanding stuff while maintaining a solid battery life and good temperatures. I think you've got a winner here.

Edit: Actually, looking into the price difference between the i5-450M and the i5-520M, I actually think the 520 is the way to go.
quex
william wrote:
Oh, that reminds me. Since she's doing AutoCAD, I would spring for the ATI Radeon HD 5470. The integrated chip is fine for 2D, but once you get up to 3D, having a dedicated card is a good idea.


Y'know, I was gonna say "oh crap, that sounds expensive," but it just so happens that this is the card the Studio 15s come with right now. :) Awesome. Good to know you approve of this model for 3D work.

Quote:
As for the desktop chips, today there's really only one notebook that'll take it, but of course it weights 12 pounds and has an hour of battery life. :P


Shucks. -_-;

Quote:
Since you're getting Windows 7 Home Premium and won't need virtualization, then you may be able to spring for an i5-450M. I will try and find the article, but the performance is about the same as the i5-520M, but it's a fair bit cheaper, mostly because it's missing some features. Might be something to look into.


We're pretty much sold on the 520, like you mentioned; it's just in the right place and at the right price.

Quote:
Windows 7 does eat RAM a lot more than Windows XP, but I really haven't found any major problems with 4 GB of RAM for typical use. If you need more, then I would agree that getting less RAM from Dell and buying a stick off Newegg will be a better deal. They [Dell] will give you two sticks though, so if you go that route, you will have to remove one. Perhaps buy 3 GB from Dell and upgrade it yourself to 6 GB (removing one 1 GB stick)?


O.< You mean after all these innovations, there are still only TWO slots for memory? GRR! I wasn't even considering that the two-slot-tango would be an issue! Shoot, well... Dell uses two sticks, really? Even for 3GB? Jerks. And, this might be outdated mantra, but isn't mismatching memory sticks a bad idea? (i.e. one 1GB and one 2GB, or one 2GB and one 4GB stick) I always thought it was good practice to match them... which led to some confusion about how to get 3GB of RAM. ...wait a minute, do 3GB sticks exist? o.o

Quote:
Oh, and always with Dell, be on the lookout for coupons and deals. You'll save a lot in doing so. The last person I know who bought a Studio 15 got a ~$1200 configuration for ~$800. Also, right now I believe the Bing cashback for Dell Home is 10%.


Yeah, I wouldn't put up with their weird ordering system if it weren't for the great deals... not sure if I can use Bing cashback with the education discount, but I'll sure as hell try.

Quote:
All in all though, an i5 and an HD 5470 with a healthy amount of RAM will easily handle just about every day to day task you throw at it along with much more demanding stuff while maintaining a solid battery life and good temperatures. I think you've got a winner here.


Yaaaaaay~! I'm so relieved. Plus, you've updated my entire grasp of computer hardware! THANK YOU!!
william
Yep, HD 5470 is plentiful for AutoCAD's 3D work. Will make a world of difference compared to the integrated chip. Efficient and cool as well.

And so far as I know, it does only have two slots. For 3 GB they have 1 GB + 2 GB (I don't think 3 GB sticks exist). As for mixing sticks, if they have the same timings, latency, speed, and voltage...it shouldn't be a problem unless you're doing dual channel. If one stick is faster, it will slow down to match the slower stick. There are some motherboards that are overly sensitive to different types of RAM, though, but I don't think the Studio 15 has had any problems. I guess you could buy the exact same stick that's present in the computer (different size of course) if it poses a problem. Let's see, a 4 GB stick off Newegg costs about $100-$110 and an upgrade to 8 GB from 4 GB at Dell is $205. Just a thought, maybe you could buy all of the RAM of Newegg and then sell the sticks Dell gives you? Because $205 for an extra 4 GB is about double what it's actually worth.
mOrpheuS
william wrote:
Let's see, a 4 GB stick off Newegg costs about $100-$110 and an upgrade to 8 GB from 4 GB at Dell is $205. Just a thought, maybe you could buy all of the RAM of Newegg and then sell the sticks Dell gives you? Because $205 for an extra 4 GB is about double what it's actually worth.

Wouldn't that be in violation of the warranty agreement ?
william
Not really. If you upgrade the RAM they obviously won't provide warranty on the new RAM modules, but they'll still support everything else. They do, after all, provide detailed instructions on how to upgrade yourself. Only if you, in a rare case, break the computer during the upgrade would they void the warranty.
Related topics
What is your operating system?
Stock Market...HELP!!!
Intel Releases New Logo & Slogan
What is better? AMD or Intel
Mac or Windows -- the cool vs. the shizznik
Engineering Degree
Reccomended Motherboard Cheap but good?
Intel single CPU will disappear?
XP v/s Vista v/s Mac OS v/s Linux
System I'm Building: Suggestions:
overclocking a processor
CPU GHz
Do Graphics Cards Run better on Certain Processors?
Exercising
Reply to topic    Frihost Forum Index -> Computers -> Hardware and Electronics

FRIHOST HOME | FAQ | TOS | ABOUT US | CONTACT US | SITE MAP
© 2005-2011 Frihost, forums powered by phpBB.