Nvidia GeForce GT 640M Review: Kepler Arrives For Mobile
Introduction, GT 640M Basics
About two months ago I wrote an less than enthusiastic editorial about ultrabooks that pointed out several weaknesses in the format. One particular weakness in all of the products we’ve seen to date is graphics performance. Ultrabooks so far have lacked the headroom for a discrete graphics component and have instead been saddled with a low-performance version of the already so-so Intel HD 3000 IGP.
This is a problem. Ultrabooks are expensive, yet they so far are less capable of displaying rich 3D graphics than your typical smartphone or tablet. Casual gamers will notice this and take their gaming time and dollars in that direction. Early leaked information about Ivy Bridge indicates that there has been a substantial increase in graphics capability, but the information available so far is centered on the desktop. The version that will be found in ultrabooks is unlikely to be as quick.
Today we’re looking at a potential solution - the Acer Aspire Timeline Ultra M3 equipped with Nvidia’s new GT 640M GPU. This is the first laptop to launch with a Kepler based GPU. It is also an ultrabook, albeit it one with a 15.6” display. Otherwise, it isn’t much different from other products on the market, as you can see below.
This is likely to be the only Kepler based laptop on the market for a month or two. The reason for this is Ivy Bridge - most of the manufacturers are waiting for Intel’s processor update before they go to the trouble of designing new products.
Normally we’d jump right in to the laptop review, but this is a special case. We’re looking at the first example of a laptop using a new architecture. Here we will take a look at the performance of the Nvidia GeForce GT 640 specifically. We will publish a separate, comprehensive review of the laptop at a later date.
In addition, while we are able to share with you the performance of the GeForce GT 640M, we’re not able to dive too deeply into the architecture because some information is still under NDA. At this time we’re only able to talk about the GeForce GT 640M as it relates to this laptop.
Kepler For Laptops - What We Can Say
Editor's Note: Yes, this is the same Kepler architecture that you will soon find in discrete graphics cards as well and is the first GPU from NVIDIA built on the TSMC 28nm process technology. We are going to have to wait to give any of the details of the new architecture a little longer but since this notebook is already on sale in Asia, we were given the go ahead to publish this performance overview. Enjoy!
Nvidia made it very clear that performance per watt was their primary concern during the design of the Kepler architecture. In a way, this seems obvious - this area is important for any new processor. But the focus on power consumption is telling. Nvidia was burned by its Fermi architecture because AMD’s components were able to provide similar performance with much lower power consumption. The green team didn’t want to see that happen again.
The performance numbers thrown out by Nvidia are aggressive. The company claims that its new GT 640M will be able to provide a playable experience at 1366x768 with high detail settings in all of the most demanding titles released last year. This means titles like Battlefield 3, Skyrim and Batman: Arkham City. All of these should run at 30 FPS or better on a GT 640M.
The part in our Acer Aspire review unit came paired with 1GB of DDR3 memory. The GPU clock is 625 MHz , the Memory clock is 900 MHz and the Shader clock is 1250 MHz. The GPU clock and Shader clock are actually down a fair bit in comparison to the GT 540M, and in addition to that, the amount of memory available is also a bit conservative.
You might be wondering how this new part can offer decent performance with relatively low clock speeds and modest memory. Part of the answer is in the architecture. Kepler is all new, and while the older GT 540M contained just 96 CUDA cores, this new part serves up 384.
Unfortunately, this is all that we can share with you about the architecture at the moment. Until the NDA lifts fully we are only able to provide information that an end-user of this laptop could discover. Look for a deep-dive into the architecture when Ryan is able to publish his review of the new Kepler desktop part.
So, let's get to the benchmarks.