Sandy Bridge - Quad core vs Dual Core for 13" notebook

[vongola]

I'm about to configure an asus u36sd which is known for its slim form factor (0.75"). The configuring options available are an i5-2410m, i7-2630qm, i7-2720qm, i7-2820qm and i7-2920xm. I want to upgrade to quad core, however I've read that 13" notebooks cannot handle the quad cores heat emissions... especially if the notebook is a 0.75" chassis. Should I risk getting the upgrade? Will battery life also be affected if i go from an i5 processor to any of the i7 quad core processors? More importantly, will heat be an issue?

 

[Chapbass]

What are the other specs on the machine and what will you be using it for? My 13" notebook (when I had one, Sony SZ650) the processor was pretty awesome on it for its day, but the HDD was terrible.

If you're mainly doing "portable" work, you might be more beneficial with a better storage solution (ie: SSD) than a quad core chip.

Of course, it all depends on how much you plan on spending.

 

[vongola]

Im gonna be using it for some programming, photoshop, maybe autoCAD plus the usual web browsing and HD streaming. Basically, it's gonna be an all rounder. When I configure the machine, i'm gonna get 8gb of ram, 256 m4 crucial ssd, and IC Diamond thermal compund to handle the temp. The tough part is deciding on what cpu to get. The i5-2410m or one of the sandy bridge quad core i7's. Anyone know how battery life would be affected?

 

[Zap]

Hello vongola, and welcome to AnandTech Forums.

If the notebook is designed to handle the heat, then heat won't be a problem. If it wasn't designed to handle the heat, then it wouldn't be sold with that processor.

I do not know how MUCH battery life will be affected, but surely it will be. For me personally, I value battery life and portability over performance in a notebook. Then again, a notebook is not (and for the near future will never be) my sole computer.

I wouldn't bother with replacing the CPU TIM in a notebook. You'd have better results by keeping the fan, heatsink and vents clear of dust.

 

[Bakwetu]

Hello vongola, and welcome to AnandTech Forums.

If the notebook is designed to handle the heat, then heat won't be a problem. If it wasn't designed to handle the heat, then it wouldn't be sold with that processor.

I do not know how MUCH battery life will be affected, but surely it will be. For me personally, I value battery life and portability over performance in a notebook. Then again, a notebook is not (and for the near future will never be) my sole computer.

I wouldn't bother with replacing the CPU TIM in a notebook. You'd have better results by keeping the fan, heatsink and vents clear of dust.

Unfortunately many of the newer notebooks actually cannot handle the heat, at least not during heavy gaming, and they will throttle the cpu. One example is the Acer timelineX series 3830GT/4830gt/5830gt http://forum.notebookreview.com/acer/ These are only using i5 2410 so I don't see how they would cope with the heat from an i7. For the more general uses that you list, I don't think this will be an issue though, but I would still go for the slower i5 cpu as I value battery life over performance.

 

[magomago]

Hello vongola, and welcome to AnandTech Forums.

If the notebook is designed to handle the heat, then heat won't be a problem. If it wasn't designed to handle the heat, then it wouldn't be sold with that processor.

I do not know how MUCH battery life will be affected, but surely it will be. For me personally, I value battery life and portability over performance in a notebook. Then again, a notebook is not (and for the near future will never be) my sole computer.

I wouldn't bother with replacing the CPU TIM in a notebook. You'd have better results by keeping the fan, heatsink and vents clear of dust.

Yeah I'm going to agree with the poster above....there is "designed to handle all thermals situations" and "Designed to work". In an ideal world, there wouldn't be an issue, but I've seen so many laptops throttle like CRAAAZZZZY when the heat kicks up. It works, its part of the functionality, if the wrote an FMEA I'm sure it would have been labeled as something like "Low Severity/Risk - Minor User Annoyance" or something like that, but its something to watch out for

 

[Gigantopithecus]

The dual core i5 is a 35W TDP CPU, the i7s are 45W CPUs except the XM which is a 55W TDP chip.

I haven't seen rigorous benchmarks of the mobile SB CPUs but if they're anything like the desktop chips, at idle, the quads will pull very low power just like the duals. At load, though, increasing TDP by 10W will definitely have a noticeable effect on battery life and heat production. 20W, same thing.

OP, have you used a SB CPU? The tasks you describe don't really need a quad core SB CPU imho.

If it wasn't designed to handle the heat, then it wouldn't be sold with that processor.

I respectfully disagree. I've repaired way too many burned out laptops to believe manufacturers only install CPUs their thermal solutions can handle.

I do agree with Zap, however, that the point of a laptop is portability. The dual core i5 mobile CPUs are extremely powerful already - don't move to a quad unless you're sure you need the compute power.

 

[vongola]

Ahh i see. Thanks everyone for the input, very helpful . To give you more details, Asus described that they were able to use a standard voltage processor because of a "dual heat pipe" design they created. The previous u36 ( same physical dimensions as the u36sd) that used the arrandale i5-480m saw idle temps of 40 degrees celsius and up to 99 degrees celsius in heavy loads.

The only programs i'm really worried about is autocad and google sketchup cause of the 3d modeling

 

[sangyup81]

In most laptops I've seen, the GPU and the CPU are cooled by the same device. That could be what's causing thermal issues in games. Lowering settings can always help