AMD Quad Cores, Oh My

Lullabye_Muse writes "From engadget we learn that AMD has plans for putting 4 cores on one die by the time Apple has fully gone to Intel processors. Full story here. They say they could eventually have up to 32 cores with scalable technology, but most programs haven't even got the ability to hyperthread, so do we really need the extra cores?"

Comments

Re:more cores, more heat

[Jeff DeMaagd]

Microsoft has said several times that one CPU package == one CPU for the purposes of licencing. They said this for hyperthreading and dual core, both still count as only one CPU. Windows XP will show four CPUs on a dual Xeon system if hyperthreading is on, and it will run.

Re:more cores, more heat

[Bill Wong]

I quote,

Microsoft Windows XP Professional and Microsoft Windows XP Home are not affected by this policy as they are licensed per installation and not per processor. Windows XP Professional can support up to two processors regardless of the number of cores on the processor. Microsoft Windows XP Home supports one processor.

MULTIthreading != Hyperthreading

[Dun Malg]

The word "Hyperthreading" describes a specific hardware kludge by Intel to make a single-core CPU pretend it's dual-cored. Apps that utilize multiple CPUUs are called multithreaded. All you dorks parroting the article submitter and calling it "hyperthreading" are idiots.

Multicore is great, but not for the obvious reason

[trims]

Yes, Virginia, we can use mutli-core. I mean, we're all into SMP heavily in the non-desktop role (does anyone actually make a "server" that doesn't have SMP?)

There are two big things I love about the multi-core Opterons: They draw less power than equivalent SMP machines (acutally, quite a bit less), and they allow multiple "CPUs" to use the same memory controller. Nominally, the second isn't a big win, but it can be for practical purposes.

Opterons have dedicated memory channels on them, so a current dual-socket Opteron has two DISTINCT DIMM banks - that is, on a motherboard with 8 DIMM sockets, 4 are allocated to each CPU socket. So if you have only one CPU, you can only use 4 DIMM sockets. Since those 4 sockets are often configured as a single bank (i.e. they all have to be filled to work), you can't add another CPU to the system without buying more RAM. This is wasteful. But with a multi-core opteron, all on-chip cores share the same memory bank.

The jist of this is that it'll be easier to have High-Compute, lower RAM configurations than it currently is reasonable to do. There are a lot of tasks out there which it is really nice to have a modest amount of RAM (say 4GB), but with huge crunch. Currently, it's hard to buy a config to do that, since you generally either end up way over-paying for CPUs, a huge number of tiny DIMM chips (which sucks for future expansion), or a larger number of motherboards, which draws more power.

And, hey, they're not tooo bad in price. Sun's dual-core v40z is less than twice as expensive as their single-core v40z, and you save lots on power/cooling/space.

Overall, a nice win.

-Erik

Intel 2005 Keynote: x10-x100 cores by 2015

[LionKimbro]

In Intel Developer Forum 2005 keynote speech, Justin Rattner said Intel is working towards having x100's, (at least x10's,) of cores in there.

He shows demos and explains several driving forces:

• voice interaction
• visual interaction (face recognition, identifying shape, video analysis)
• 3D graphics
• machine learning

An example of video analysis is demonstrated. You can get a stable image out of a cell phone, and get a much higher resolution to boot, simply by analyzing lots of images in sequence. Right now, it takes a lot of time to crank out the analysis. But the problem is parallelizable, and Intel thinks we'll have this sort of things in cell phones by 2015.

This is also the technology behind automatic construction of 3D from images. This is where you pull your cell phone out, walk around, waving it around the room, and get back a 3D model of the room.

People ask: "Do we really need all this computing power?" Yes, yes we do. There's plenty of stuff to do with it.

Scott talks about sitting in front of the computer, and not needing to log in, because the computer knows who you are by your face.

There's all kinds of stuff to do with it.

Re:Doesn't have to be threads

[imsabbel]

You dont understand:
HYPERTHREADING =! MULTICORE.
These are 2 complete cpus+a crossbar switch on one die. No shareing of execution units/registers,no sharing of anything but the ram bandwith.

Amd dual core cpus are FASTER than 2 single core cpus in dual socket boards (with the exception of extremely bandwith demanding streaming applications) simply because of much faster on-die cache coherence communication.

A quad core cpu will most likely see more bandwith problems, but could (with ddr-2, ect) still be very well in the same class as a 4 single-core machine.

Re:Are more cores like hyperthreading?

[Mad Merlin]

Hyperthreading is, esentially, a hack to make one processor look like two. In an ideal situation, this will yield better performance when running more than one application at the same time, the situation is rarely ideal however. In practice, most single threaded applications will end up running at roughly the same speed. The downside is that some applications will not function correctly, or will run slower with Hyperthreading enabled.

SMP or multiple cores is (obviously) more than one real processor and one will see huge benefits with any application that is multithreaded as well as when running multiple processes. Single threaded processes should never have issues running on an SMP system, though there will be a small loss of speed due to the overhead of SMP (Dual 2 Ghz processors will probably run a single threaded process ~1% slower than a single 2 Ghz processor).