Mobile GPU Faceoff: AMD Dynamic Switchable Graphics vs. NVIDIA Optimus Technology

Switchable Graphics - Meet the Contenders

Before we get to the actual meat of this review, we have a disclaimer to make: both laptops we’re comparing came to us via NVIDIA. Now, before anyone cries “foul!”, let me explain. First, we asked AMD for just such a laptop back in May, and they haven’t been able to get us one yet (though it’s likely as much the fault of OEMs as AMD). We also only just received our first Sony laptop (from Sony) in a long while, and we received the VAIO C from NVIDIA first. Finally, the laptops came boxed up, unopened, with all the standard fluff you’d expect from retail notebooks.

After unboxing, we did our usual thing: create a new user account, and then commence uninstalling the bloatware—and yes, the Sony VAIO C and Acer TimelineX 3830TG both have a lot of it!—and when all that is done and we’ve shut off any unnecessary applications and utilities, we start installing our benchmark suite. After that’s done, we do a full defrag (using Defraggler) and then we can start testing. Despite the source of the laptops, then, we are confident that both are reasonable representations of what you’ll get—actually, the TimelineX 3830TG has some issues with throttling in games, so if anything NVIDIA’s choice for their own platform wasn’t the best, though the Sony VAIO C may not be the greatest AMD offering either.

In terms of other alternatives, while there are dozens of currently shipping Optimus laptops (ASUS, Clevo, Dell, HP, MSI, Samsung, Sony, Toshiba, and others are all onboard with the platform), finding laptops with Intel CPUs and AMD dynamic switchable graphics is a lot more difficult. Sony has the VAIO C—the VAIO S we recently reviewed doesn’t support dynamic switching, instead using the older manual switching—Dell has the Vostro 3450/3550, and HP has it with certain dv6/dv7 series laptops using 6700M GPUs. Meanwhile, 6300M (rebadged 5400M), 6500M (rebadged 5600/5700M) and 6800M (rebadged 5800M) can't support dynamic switching, and no one is trying to do it on 6900M. (Note: I’ve looked around for more details on which laptops support AMD’s Dynamic Switchable Graphics and came up empty, but if anyone can find a comprehensive list I’ll be happy to post it.) There may be a few other laptops out there with Intel CPUs and AMD 6000M GPUs, but there definitely aren’t as many options.

We’ll be running a few benchmarks later, so while we’re on the subject of laptops, let’s go over the full specs. Starting with the AMD Sony VAIO CA laptop, here’s what we have:

The OEM-only i5-2410M is a good entry-level Sandy Bridge processor, and pricing is only slightly higher than the base model i3-2310M (which is clocked at 2.1GHz and lacks Turbo Boost support). 4GB RAM is fine, and the HD 6630M is actually a fairly potent mobile GPU as we’ll see in a moment. The big problems with the VAIO CA are that it comes with a slow and rather outdated 320GB 5400RPM hard drive (Western Digital Blue) and it also has a ton of bloatware. The bloatware can be uninstalled, and we did that as our first priority, but the hard drive tended to be an ongoing concern. AMD’s Catalyst Control Center for instance pops up in a couple seconds on my desktop (Bloomfield + SSD + HD 6950), but on the VAIO C there are times when it can take upwards of 30 seconds (with the HDD activity light a solid orange). Games also tended to take a bit longer to load than we’re used to. Outside of those two areas, the VAIO C is pretty much standard consumer laptop fare: glossy 1366x768 LCD, decent but not exceptional build quality, and average speakers. The keyboard is decent, though I’d still prefer dedicated document navigation keys (rather than the Fn+cursor combinations Sony uses), and it does have nice backlighting.

On the other side of the table is Acer’s TimelineX 3830TG-6431, priced over $200 cheaper than the Sony. Acer has a habit of releasing laptops and then discontinuing them not long after, only to replace them with slightly different models, so we can’t guarantee the 3830TG-6431 will always be in stock; however, it appears readily available right now. The AS3830TG-6431 has on serious problem, unfortunately: the CPU tends to throttle down to 1.2GHz when gaming as the CPU and GPU end up creating more heat than the system cooling can handle. That’s a real shame, as if it weren’t for the throttling there would be a lot to like with the 3830TG.

For one, the floating island keyboard I detest so much on other Acer/Gateway laptops is gone, replaced by a chiclet-style keyboard. There’s a bit of flex but I can live with it, and the layout is good (except for the crazy backslash-joined-to-the-enter-key weirdness). This is also a very thin and light laptop, helped by the absence of an optical drive, and the dimensions would be very impressive given the i5-2410M CPU and GT 540M GPU if it weren’t for the thermal throttling problem. Acer gives the TimelineX an aluminum cover and palm rest as well, but the LCD is one of the worst I’ve used (poor viewing angles and weak colors, plus our sample has a red pixel in the middle center of the LCD that’s stuck).

Because of the throttling issue, the 3830TG benchmarks aren’t the best representative of what you can get from NVIDIA’s GT 540M. We’ll include two other laptops with the GT 540M (and Optimus) in most of our benchmarks as alternative reference points: the Alienware M11x R3 (i7-2617M CPU) and the Dell XPS 15 L502x (i7-2630QM). In theory, the i5-2410M should sit somewhere in between these two in terms of performance, but the throttling drops it lower in most tests. However, if you’re willing to play around with a utility like ThrottleStop, you can actually get the CPU to run at a constant 2.1GHz without any throttling (basically using the i5-2410M as an i3-2310M CPU). We tested with ThrottleStop set at 2.1GHz along with running “stock” (e.g. with throttling) to provide a couple more points of reference in our gaming results.