Anybody have the scoop on exactly how much the Dual core processors save on power? I imagine the processing is pretty small in the power department (HD and Wireless are probably much greater, or is my WAG wrong?).
So I guess my question(s) would be:
1.) Do the Dual core processors half the power consumption used by the processor compared to the single core? Do Quad Core processors (which I guess at this point are just two dual core processors fused), offer any benefit over dual core?
2.) What overall power savings would a laptop exhibit? Would I expect my 3 hour battery to last another hour, or would it only add minimal savings?
I tried looking this information up via google, but apparently I am not very good at it, or the page rank stuff is working against me, all I kept getting was snips from somebody selling one touting its power saving capabilities (but no raw data).
I have read in some reputable PC magazines that quad core processors don’t offer any benefit at the moment because software just doesn’t take advantage of them at all. They will at some point in the future though although it could be a year or three. The fastest processors in software tests today are actually dual core rather than quad core. They are the dual cores at the higher clock speeds. Quad cores are usually clocked slower.
Dual core chips aren’t inherently any more efficient than a single core. If you compare chips within the same generation, a dual core processor will suck down (roughly) twice as much power while idling, and twice as much power while at full load. Most of the time one of those cores will be idle, so on average, within the same generation, a dual-core will consume slightly more power than a single core chip. Same applies for quad cores. All you’re probably hearing about “performance per watt” really only applies to big server farms and supercomputers.
However, Intel’s current generation (the Core 2 Duos) of processors happen to be both dual-core and low-powered, for unrelated reasons. The power savings mostly come from improvements in the manufacturing process and a redesign of the chip.
Are you asking about upgrading the processor in your laptop to one of the shiny new Core 2 Duos? First of all, it may not be possible. It’d have to be a pretty new laptop to have the hardware to support the newest processors; no more than a generation old. And in that case, you’re probably using a pretty recent model of laptop processor like the Core Duo/Solo or Pentium M, which already had very low power consumption.
The once case I could imagine this upgrade being possible would be if you had a laptop from about a generation ago that used a much more power-hungry desktop chip, like a Pentium 4/D. And in that case (in my mind unlikely) you could very well see a major increase in battery life.
If you gave some specific details about your laptop (manufacturer and model will be fine if you don’t want to hunt down all the technical details yourself), somebody could probably come up with a more definite answer.
Upgrading a laptop’s CPU is almost always impractical, if not impossible. Nearly all laptops have their CPUs soldered to the motherboard, and the ones that don’t use proprietary daughter cards. The only laptops I know of that can have their CPUs upgraded are certain models of Apple PowerBook systems.
Bwuh? I can’t think of a recent mobile CPU that isn’t socketed… Intel had Socket 479 and now uses Socket M; AMD has Socket 563 and Socket S1. I’m not aware of any vaguely recent laptops where the CPU was actually soldered down. And what is this about daughter cards? If the CPU is mounted on one, it’ll be in one of those sockets. I had to muck around inside my laptop recently, a Sony Vaio, and its processor was in an ordinary socket…
Maybe you’re referring to other Apple models? I can’t say I have a clue about their innards, though I’d be willing to bet that any of their Intel models are socketed just like with PCs…
I agree that getting to the processor to switch it out will be a huge pain in the ass with most laptops. You often have to take the whole damn thing apart, which is not a task for the faint hearted (or statically charged). This is a task about an order of magnitude more difficult than adding RAM to a desktop, for example. Still, if you want it done and aren’t comfortable yourself, you could pay someone else to do it or find some friend or relative who knows what their doing.
This is basically true. Both AMD and Intel have implemented an automatic underclocking feature that slows down the chip’s clock speed and therefore its power consumption when idle, so all of the multi-core parts from 2005 or newer will be more efficient than their older brethren. But as lazybratsche notes, a single-core from the same generation will also have this technology, and will be running fewer cores overall.
These improvements will also be coming to AMD chips in early 2007. In fact, I thought we should have seen the first AMD 65nm parts last week, but I didn’t see an announcement. Doesn’t mean it didn’t happen though.
Rather than trying to save battery power by replacing the chip, consider underclocking your current chip using a software utility like Crystal CPUID or adjusting the BIOS settings. If you’re reading from a CD, copy it to the hard drive using wall power before you get on your flight or trip, and then disconnect the CD/DVD drive (optical drives have lasers and motors, both of which burn lots of power; your hard drive is going to be on no matter what). You can take this to the extreme by setting up a hardware profile in Windows that disables most of your peripherals (speakers, sound jacks, antennae, and so on) so that your machine is just a hard drive, a dimmed screen, a keyboard, and maaaaybe a mouse.
That’s not the only form factor mobile CPUs come in. There are various BGA (ball grid array, rows of little solder balls on the bottom of the CPU) formats designed for direct attachment to the motherboard. Standard CPU sockets in laptops, though, is new to me. I’ve never heard of that before.
Hmm. Must be a Mac/PC thing. Makes sense though, most PC laptop makers give their customers a lot of room to configure something and socketed CPUs lets them mix and match their chips. OTOH, Macs are bought as one of a handful of specific models.
