Anandtech's Kepler GT640m review

Didn't see this posted already, so decided to post it. It is actually a review of the new Acer Aspire TimelineU M3 with the 640m -
AnandTech - Acer Aspire TimelineU M3: Life on the Kepler Verge

 

Look at the way it is crushing the 540M (HD 6650M). It would have crushed it much more than that if the two notebooks had the same CPU too, but its unfair comparison because the Acer have a 17W CPU that is able to turbo up to 2.8GHz, while the Sony have a 35W CPU that is able to turbo up to 3.4GHz.

Same performance as the GT555M ( Another review), but 1.5 hour more battery life. Again unfair comparison since the Alienware M14x have a 45W 2630QM Quad core.

I`d say it is Kepler worthy

 

How come it have more Battery Life on idle if Optimus switches the discrete GPU off in both cases (since they are not being used when idle)? Doesnt that concern the CPU runtime then only?

 

Still no TDP on 640m, can't properly compare to previous gen , don't think we'll know until at earliest 23rd maybe?

 

No tdp but looking at how thin is the notebook reviewed, you can assume it has a low tdp.

So knowing that, i would say the performances look amazing.

 

guys we are talking about gt 555m within ultrabook = craziness...

ridiculous performance buff, Kepler indeed looks amazing

 

tdp is probably for the gpu in non-turbo-boost state

 

TDP is the maximum power state as designed, only way to exceed that is to manually overclock it, -the turbo-boost like feature won't kick in if it's near it's TDP. The notebook is rather wide/thick for an ultrabook, I'm assuming that it would have been possible to put a 540m in that chassis and manage with the power but it would be hotter.

 

That GT640M will be great in the Alienware M11X!

 

We can only speculate but people shouldnt expect wonders.. These GPUs are faster because they have more transistors, thus create more heat.. Now it does run at a lower voltage, but if you squeeze out more perfomance of these chips they do run hotter, and notebook cooling solutions havent improved alot for a long time.. Now turbo boost sounds like something that really pushes the thermal limit when intensively used.. Now that there are a bunch of ultrabooks announce with dGPU such as the 640m in it, it doesnt mean that it wont create common problems such as throttling or overheating, just means the market for these are right..

I think kepler is powerful, very powerful.. But the question is (from a notebook perspective) if powerful = heat

 

I am pretty shure that Intel, AMD and Nvidia have TDP ratings on all their products so that notebook OEMs know how good cooling their notebooks need, included how much the maximum heat (TDP) is with the turbo.

If not there would be catastrophic events happening

 

Notebook manufacturers are notorious for "good enough" cooling solutions though. It always struck me as odd that there should be a market for "Cooling Pads" and what not.

 

Yeah good point. Maybe Acer didn`t pay too much attention to the cooling. After all, it is just a thin ultrabook.

 

There are, do you know how many Sandy Bridge notebooks throttled? It was a total catastrophe!

I can give you a whole list of notebook models that throttled!

 

Yup, I`ve heard about them. But that wasn`t Intel`s fault.

 

ofcourse not, throttling is a security measurement to prevent overheating..

It was the laptop manufacturers fault, just like in the case of the timeline ultra..

 

I dunno. TDP's are loose specs especially with using Boost these days. Even though Intel specs out TDP, the laptop manufacturers definitely better have a handle on how well their machines perform with the chips they're offering. I'm sure some make the executive decision that limited boost is acceptable to cut weight, thickness, and cost.

 

Boost is actually a double-edge sword. In systems with good cooling, assuming unlimited boost, one can get better performance than the card is intended for.

However, that is not to say that manufacturers will always have great cooling designs. In order to maintain a certain thinness and acceptable weight targets, sometimes cooling is neglected in small spaces and the boost just cannot run for long, resulting in less performance.

In fact, turbo is bad when manufacturers can now say, turbo is a bonus and as long as the core speed is maintained, no throttling...

 

Really? How much cooling can one expect from a 20mm (wafer thin) chassis? At any rate, a dedicated GPU like the 640m in a chassis so thin is a game changer. Nvidia might have hit a home run when it comes to power consumption and mobile GPU's.

 

Actually a smaller manufactoring process can also mean more heat.. since there is less distance between the transistors you can put more of them on a smaller die.. But when maxed out they create more heat (when they turbo boost for example)..

Also supposedly the ivy bridge mobile cpus are more likely to throttle (atleast some respected forum member from an alienware forum says so) when they turbo because of more heat.. but up to this point this is just speculation

He also said though that the m14xr2 is kind of castrated because its chassis (its the same as the m14xr1) cant handle the full power of an IVB cpu + mobile kepler, so they had to limit the power somehow.. the guy is an engineer working for dell and posts under a nickname

and many people who have owned an m14xr1 with a quad know about these heat problems

 

You sure about that Gamba? Its been my experience that a Die Shrink results in a cooler operation, unless there is an increase in transistors. The smaller the die, the smaller the transistors and logic circuitry.

When you shrink things down, there is less energy required to operate the part, so the overall wattage of the processor decreases.

Less energy in, Less heat out.

Now, there is something to be said about density, but the energy-to-density ratio scales to where the parts run cooler.

In the simplest sense, its like a 100w light bulb, vs a thinner filament in a 40w bulb.

Now.. You WILL see increases in thermal if you add more transistors. A die shrink often comes with the room to add more Cache, more Cores, on-board memory controllers, GPUs, etc.

 

And you can find a review of it here on NotebookReview as well. Acer Aspire Timeline Ultra M3 Review: A True 15-inch Ultrabook

 

The energy use per transistor goes down. If you include more than that percentage transistors then power consumption will go up.

 

So you think the more transistors create less heat?

A die shrink would run cooler if it uses the same transistor amount as a 40nm gpu chip, but if you pack in more transistors you get more heat.. Obviously the advantage of having cooler chips is used to squeeze out the maximum perfomance out of them.. its simple physics, you think that NVIDIA can magically gain a 50% perfomance advantage over the previous generation, while having GPU chips that create even less heat ? The turbo boost may sound like a good idea if its executed good, but if its something like intels turbo boost, it could create alot of heat and throttling. Perfomance comes with the cost of heat

Im not saying that the new mobile chips will run hot and/or cause throttling, but it is very likely

 

Well considering that an overclocked and overvolted 7870 uses less power than a stock 6870, I would say things are looking good for the high end AMD mobile chips.

 

Exactly. They tend to cram more and more on it.. or run it at higher frequencies with each die shrink for the performance.

However, they can also leave the architecture the same and lower the TDP, allowing a more powerful part to go in a more heat-constrained space like an ultrabook.

Its just what you want to do with the advantage and die.

 

Well in this case it seems they tried to get the most perfomance out of it, the 640m is about 60% faster than the 540m, which is an extreme perfomance gain

Im not worried about the GPU running too hot, but rather the combination of CPU+GPU which will share a heatsink (in many cases) to cause throttling

 

I agree.. bad design to share the heatsink. Even a 1mm gap, splitting the cpu and gpu heat sinks could alleviate the issue.