That's disappointing, because while the CPU will likely remain close to state of the art for quite some time to come, you'll most likely max out the memory on day one and be stung by an inability to upgrade.

Of course, this was probably by design, so that they can sell you another, virtually identical 8 core processor in two more years for another $999.

http://ark.intel.com/products/82930

At Penny Arcade Expo.

Times really have changed.

http://www.parallax.com/microcontrollers/propeller-1-open-so...

8-core microcontroller in 2006, not bad. They're releasing a better one later this year, so they've opened the verilog design for the current one.

I do molecular dynamics simulations with LAMMPS, and I've noticed performance on my laptop is best with 4 cores. Using all 8 "virtual cores" is actually quite a bit slower.

Cost per operation? Can get an AMD 8 core processor, 125 Watts, 4.0 GHz clock, for about $180. So, $1000 for an Intel processor with 8 cores with hyper threading stands to be cost effective? In what sense?

Not necessarily -- as AMD fans (I'm one) have seen, the entire "more cores is better" is not always true -- it heavily depends on the workload, and frankly, most games and programs are not utilizing these cpu's fully (yet). Now, put something like a 2 x 16 core Opterons in a server and you have yourself quite a powerful virtualization platform.

With that said - I'm interested in seeing it's price point and performance compared to AMD's offerings.

AMD already has an Operton 16-core processor. I'm not saying that AMD is any better, but I thought Intel would have started selling these from long ago, judging based on the pace of the computer industry.

In hyperthreaded processors, each core can be further split into two "threads". These threads share most of their hardware resources; you can think of them as a thin veneer over a single core. These threads execute simultaneously, making use of whatever resources their partner isn't using at the moment.

Some examples (assume a single core processor with 2 hardware threads for each): Imagine you're running a thread, and it needs to access main memory before it can continue. Depending on the chip, this will take hundreds or even thousands of cycles before the thread can continue. Hyperthreading is one way to make use of this time; the other thread can run at full steam while the first is waiting to get its results back from memory.

Another positive example: you're running some floating point DSP code (perhaps your music player's equalizer) at the same time that you are compiling a new build of a program. The DSP code will make use of a mix of integer and floating point resources, while the compiler will probably not need to use the floating point units at all. Hyper threading allows the music player to use those resources that would otherwise be idle while the compiler is running. The DSP code will slow down the compiler because it is competing for things like integer resources (which are needed for pointer arithmetic, for instance), however there will still likely be an improvement over normal multitasking on a single hardware thread.

Now, for a negative example: you are running two very demanding threads. These threads are painstakingly programmed to use almost every resource they possibly can at any moment, they very rarely need to stall to access memory, etc. In this case, the two threads will only waste time fighting over the same resources, kicking each other out of cache, etc, and it would ultimately be more efficient to disregard hyper threading and run each thread sequentially.

Another negative example: you are running two instances of the same thread. This will result in good utilization of some resources (such as code cache, because each thread is executing the same program) but practically guarantees contention over the execution units, even if the program isn't that demanding.

To sum it up, hyperthreading is usually a net positive for desktops where you have a very heterogenous (and often not anywhere close to optimally programmed) mix of programs that need to run at once, and usually a net negative for high performance computing programs like your molecular dynamics simulation where every thread is executing the same extremely demanding program at once.

EDIT: And to go a bit further and explain what makes GPUs special, they're basically the inverse of a hyper-threaded CPU, great at running a lot of homogenous threads. Instead of having independent threads sharing the same resources, they have the same logical thread (many designs sharing the instruction pointer amongst many hardware threads, thus causing each to execute the same instruction at any given moment with different inputs) shared across cores that have their own indepedent execution units.

The simple explanation is that you have a core with its set of execution resources. Instead of using those resources to satisfy just a single execution context the processor has two execution contexts, which run independently of each other sharing the resources. This can potentially result in large gains when you have a workload which often leaves a execution stalled waiting on ram, though less than you might guess because there are overheads and because modern processors are already able to extract a fair amount of parallelism out of a single thread.

It works out less well for software that sees non-trivial overhead when running more threads, or when more threads increase cache pressure too much.

The problem of molecular simulation is that it's almost entirely composed of floating point instructions. Thus, hyperthreading can't run them in parallel at all.

http://oirase.annexia.org/multithreading.ps

The more CPU-bound and similar (between them) the tasks are, the less HT is going to make a difference

It made sense for single-core P4 and Atoms, but for an 8-core processor, the efficacy of HT is debatable.

OTOH, AMD will let you use ECC, which would be nice; the Intel processor includes a video card on board, if that's of interest.

One Haswell core is equivalent to two AMD cores. But yeah, AMD is dramatically cheaper than Intel for equivalent performance.

Intel has had better performance per watt for years, and an "8 core" AMD processor and "8 core" Intel processor are not equivalent.