[Hodar]

Available today - yes
Mainstream - no

The present addressable memory limit with IA32 is 4 Gig. Once upon a time, a machine with 1 GB was unheard of; today it's commonplace. We are fast approaching the 4 Gig barrier.

iAMD-64 bumps the addressable memory limit from 4 Gig, to 256 TeraBytes. Let's just say that 256 TeraBytes of DDR is a really BIG jump forward.

Neglecting PCI-express and multiple Hyper-Transport links (ie. dual core 64 bit processors in a single package; that drops into your existing motherboard), this is where we are going. Nvidia and ATI have already released PCI-express Graphics engines, which bump performance upwards of 300% over existing technology.

Gamers will very likely be among the first to jump on the bandwagon. Next will be those who want to up-band their video through a graphics engine to their HDTV. iAMD64 will rock the world like Intel did with the Pentium against the x486.

[CyberCowboy777]

You nailed it.

This is going to be big - and FUN!

[Myrddin]

I'm wondering if the hyperthreaded Intel CPU makes life more interesting when testing a multi-threaded program. A real two processor machine introduces the possibility of concurrent access to the same memory location, thus the need to include flawless concurrency locking schemes. If the hyperthreaded CPU acts identically to a real 2 CPU machine, I'll spring for one of those ASAP.

[SauronOfMordor]

The present addressable memory limit with IA32 is 4 Gig. Once upon a time, a machine with 1 GB was unheard of; today it's commonplace. We are fast approaching the 4 Gig barrier.

You are confusing physical memory with address space. A Pentium III from 1999 is able to address up to 64 GB of physical memory. It's just that no single application process can have more than 4 GB of virtual address space.

There are lots of applications, particularly in database applications, where you would want to be able to address much more than 4GB, even if you have less than 4GB of physical memory -- namely it would give you the ability to map your entire database into virtual memory.