buying a laptop ; intel dual core?

I need to purchase a laptop for school (it's a requirement), and I want to buy something that I can also use for game programming. Money isn't really an issue, but I am very apprehensive about how useful Intel's dual core processor technology would be for me.

I've been reading about the Intel dual core processors here:
http://www.intel.com/technology/computing/dual-core/

In general, my laptop will be used for academics (which requires little processing power) and game programming. The dual core technology seems like it will be most useful for multimedia applications, or anything that needs a lot of things to be done in parallel...big time multitasking, but I highly doubt it will yield any sort of an FPS boost or latency reduction in anything interactive.

On my current system, which is an older P4 with a high clock speed (released before P4 extreme edition), I had decided to disable the 'hyper threading' technology, which attempts to handle executions in parallel, a simulated 'dual core'. Ultimately it made things run like crap (menus in windows would take slightly longer to pop up when I had it enabled, programs took longer to start, input from programs was delayed, and in my own programs a slight increase in the time it would take to render a single graphics frame).

The only redeeming quality about the hyper threading technology is that it was only simulated, and could subsequently be turned off...not the case with the physical dual core processor.

Anyone care to opine?

I got a pretty nice Acer for $699 with a Pentium M. :)

Dual-core does boost the price quite a bit, I'm not sure how much it boosts the processing power. I'm sure both cores are used at all times, there is always multiple threads that need to be processed at any given time, so there is a boost. If money isn't an issue, I'd say get it, otherwise, Pentium M processors are more than enough for school work. I also have no problem running programs like 3DSMax on my laptop even if I add smoothing filters that add a lot of vertices.

That's all I have to say.

>I am very apprehensive about how useful Intel's dual core processor technology would be for me.
There isn't a lot of software on the market that takes advantage of the simultaneous processing that a dual core processor offers. More likely than not, you'd be making an investment toward the future, rather than getting the best of the now. ;) But after saying that, I'm very happy with my dual core.

I have a Dell Latitude with a intel dual core processor, and I can't complain. I haven't had any problems running games on it, though admittedly I haven't played a lot (mostly Battlefield 2)

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Originally Posted by SlyMaelstrom

I'm sure both cores are used at all times, there is always multiple threads that need to be processed at any given time, so there is a boost.

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Most of the time in an OS, no CPU is used at all. Like when you're sitting there, thinking about what to write next. Or simply if you're typing away with your horribly slow human fingers.
Also, perceived performance is how long it takes to complete the task you're waiting for right now - which, usually, is something that is single-threaded (and most often I/O-bound), so you don't get a benefit from multiple CPUs either.
The only real benefit is for computation-heavy stuff like 3d rendering and media en/decoding. Otherwise, current programs are simply not equipped to make a chance in perceived performance with multiple CPUs.

A dual core may set your lap on fire and drain your battery much faster.
I would go with an M if your not planning on developing apps which are made to utilize multi-core.

There is a new CPU being marketed that has the claim 'dual-core no more'. I'm not exactly sure of the type of CPU since I'm not an Intel guy. However for laptops, choice of CPU is a luxury you probably don't have.

I would highly recommend that you go for the core duo.. I have used it and performance seems good and even benchmarks seem to prove this...


Though app which take advantage of this is required to exploit the full potential even single threaded apps will run faster on a core duo as it can execute instructions which do not have inter dependencies/hazards between them to be executed simaltaneously...

consider the following assembly code for a app (even a single threaded app)..

Code:

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SINGLE CORE

1 ADD r1,r2,r3
2 SUB r7,r4,r5
3 ADD r2,r3,r8
4 ADD r4,r7,r5

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the above code can be executed in parallel on multiple core as follows without changing the end result

Code:

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CORE1              CORE2
 
1 ADD r1,r2,r3    1 SUB r7,r4,r5
2 ADD r2,r3,r8    2 ADD r4,r7,r5

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this will result in the same code being executed in half the time in a best case scenario...


hyper threading was a completely different ball game.. it just used a single processing core but emulated multiple sets of the same registers so as to avoid context switching overheads but had performance issues in some situations.. and it relied heavily on application/operating systems to take advantage of this feature where as the core duo is transparent to the software and in most cases does not require any changes to take advantage of its feature

>>A dual core may set your lap on fire

lol...and heat lowers sperm count!

>>But after saying that, I'm very happy with my dual core.
Do you have any further specifics about this statement? e.g. a particular application that you have observed running particularly fast, a benchmark to cite, or home-grown software of your own that works particularly well with your processor? Again, the only 'specialized' application I could have for my laptop is writing my own games...to make the situation more sticky, my tastes and interest lay in the realm of CPU-intensive physics implementations instead of a bias towards GPU-intensive graphics intensive, meaning my choice of a CPU is especially important.

>>(mostly Battlefield 2)

Well, from what I've seen that's a pretty intense game (in terms of computational requirements)...if you've got a laptop that can run that decently, then my guess would be that's a pretty decent system.

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There is a new CPU being marketed that has the claim 'dual-core no more'. I'm not exactly sure of the type of CPU since I'm not an Intel guy. However for laptops, choice of CPU is a luxury you probably don't have.

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What do you have? I haven't bought a new computer in a couple of years, and to be honest I also haven't been following the latest computer trends (the desktop I bought two years ago was top of the line then, and as far as I can see is still excellent).

As a side note, the front side bus speed vs. the memory speed on any intel system configured on dell doesn't match...on the config. I'm looking at, the fsb speed is 667MHz, while the memory is clocked at 533 (dual channel)...I thought the FSB and memory speed had to either be equal, or in some integer multiple of each other.

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it just used a single processing core but emulated multiple sets of the same registers so as to avoid context switching overheads but had performance issues in some situations.

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Yeah, this is def. what I had observed with my system that supports HT... my concern is that a 'real' dual core proc. instead of a so-called 'real' dual core proc. will have the same problems I observed with the hyper threading technology. I'm also afraid that I'm making over-simplifications and that the dual core might actually be insanely fast in all scenarios.

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Also, perceived performance is how long it takes to complete the task you're waiting for right now - which, usually, is something that is single-threaded

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Yeah, this is exactly why I'm leaning towards choosing the fastest single core proc. that I can afford. If I was into multimedia applications I think I'd go for the dual core, but I think I'm going to just simply get the single core with the most amount of memory and the best video card I can get.

One other question that I have not been able to find anywhere else...what is the FPU architecture of the dual core cpu? Does each 'core' have its own floating point processing unit? My guess is that it'd have to, but the articles I've read are not 100% clear about this. Hmm.


Thanks for the replies, I appreciate it!

Nowadays, the FPU is just part of the CPU, so I think it's safe to say they have their own FPUs.

BTW, I doubt that what vasanth described could actually work. The situation of such independent instructions is rare enough that the coordination of distributing it to two CPUs (or even CPU cores) would drown out any advantage. Besides, that's what superscalar and VLEW (PowerMac and IA64 are examples of each) architectures are for.

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Originally Posted by CornedBee

Nowadays, the FPU is just part of the CPU, so I think it's safe to say they have their own FPUs.

BTW, I doubt that what vasanth described could actually work. The situation of such independent instructions is rare enough that the coordination of distributing it to two CPUs (or even CPU cores) would drown out any advantage. Besides, that's what super scalar and VLEW (PowerMac and IA64 are examples of each) architectures are for.

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well actually the core duo itself uses certain super scalar techniques.. so yes it has certain advantages and disadvantages of a super scalar processor...

and one more thing to consider in single core processors such as Pentium D etc is they achieving a higher clock rate with substantially longer pipelines when compared with core duo (31:14) and this itself reduces the performance of single core processors though they run at a higher clock rate due to bubbles in the pipeline..

so overall the core duo seems to outperform other single core processors in theory and is supported by various benchmarks tests

http://tomshardware.co.uk/2006/07/14..._athlon_64_uk/ and any similar benchmarks...


and some one mentioned abt power consumption, the core duo is one of the processors to have quite a low power consumption....

The actual execution of instructions is not as linear as vasanth described even in a single core processor. Intel and AMD both have made huge strides as to when the CPU must fetch. Actually modern CPUs fetch very rarely and when they do they fetch chunks. Those chunks are broken up into executable blocks of instructions and then pieced together as executable chunks to create the final executable chunk. All the while this is happening, other chunks are also being executed in parallel. The new CPUs support predication, branch prediction, etc, etc. There is a lot going on under the hood - a lot more than just super hyped core clock speeds.

The entire process is extremely confusing and I don't completely understand it. Dual core will get you some performance. Will it be enough of a change that you will notice it? Probably not without some benchmarking software. We are not a good judge of how 'fast' something executes and often times we are dead wrong. Such is the case with trying to optimize code, without using a profiler. Usually you end up optimizing what you 'think' is slow and ignore the part that really 'is' slow.

Its pretty simple really, if one core is good... than 2 cores is twice as good. My laptop has 2 cores, I've consulted with both of them and they agree.

Ask them about the dual-core AMD chips see what they say about those.

Generally, AMD chips run WAY to hot in laptops..... I'm glad Apple chose Intel for their laptops, although I think AMD might have a slight oomf over Intel when you talk about speed.

I'm extremely happy with my (dual-core) MacBook. Yes, it does get toasty, but not overly warm. Besides, most of your work on a laptop is actually done on a desk.

Even AMD dual-core is a bit hyped. There comes a point at which performance becomes a matter of an app loading in 2 seconds, or 3. For me, 3 seconds is not worth the price tag.

I've got an AMD 3200 XP with a GeForce 7800 AGP (yes AGP) and I have no frame rate issues on any games. Granted it's not an AMD 64 FX 50 with a GeForce 7800 GT PCI-E, but it still gets the job done.

When it comes to laptops, just buy what is going to get the job done - or the most bang for the buck.

I'm not saying don't go dual-core, I'm saying don't just get it because of the hype. Hype sells, but hype rarely delivers what it is selling.

Dual core is a nice option for Gentoo Linux people :D I am waiting for the prices to come down on the chip I have my eye on, and then I am gonna grab one, flash my BIOS and enjoy extending the life of my socket 939 board for as long as I can..

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Originally Posted by Bubba

... with a GeForce 7800 AGP ...

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How did you get an AGP version? I bought a 7600GS a little while ago and was forced into getting PCI-E (and subsequently upgrading my motherboard) because AGP wasen't available.

I have a dual core, and it most certainly is worth the price. People may say it is worthless for things other then games/graphic work, but it is good for anything. It allows you to multitask. You could be programming, listening to music, debugging your software, etc all at the same time without any performance loss. Plus, most things are going to eventually become multithreaded.

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Plus, most things are going to eventually become multithreaded.

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Everything sounded good till that line. Everything now is multi-threaded.

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Originally Posted by kermit

Dual core is a nice option for Gentoo Linux people :D

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What's our particular advantage?

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Originally Posted by CornedBee

What's our particular advantage?

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Gentoo linux is now multi-core. They've included two parallel copies of the kernel on the same piece of linux. The first one manages the computers resources while the second one provides a flashy name.

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Originally Posted by CornedBee

What's our particular advantage?

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I remember reading somewhere of a shootout between the FX-57, the X2 4800+ and Intel's best chip at the time - anyway, when it came to compiling applications (running Gentoo), the 4800+ spanked the other chips - IIRC it compiled Firefox in less than 15 minutes.

This is completely unrelated...... but I have a friend who has a laptop that literally has a AMD 64 chip inside his laptop! The battery on a full charge lasts less than an hour. Maybe you should get one of those :).

Ah yes, Gentoo can of course make great use of parallelism.

Well I went with the solo core, and it just arrived today. I am very happy with it. I actually would not have bought a laptop if my school did not require it. They also require that the computer have wireless networking capabilities...this is my first laptop, and I was tickled pink to be going poop while reading the news! I am not, however, pooping while I post this.

As a side note, I totally forgot that my router also had wireless capabilities, so when I started my computer and it said it was connected to the internet, I was actually mad because I thought something was wrong...then I went to yahoo.

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Originally Posted by BobMcGee123

and I was tickled pink to be going poop while reading the news!

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Some things are better left unsaid. ;p

But It Was So Exciting Man!