Re: [Hampshire] [Hardware] - 64 bit Fedora

On Thu, Nov 22, 2007 at 07:11:19PM -0000, Rob Malpass wrote:
> I was told today (by a sales rep) that all CPUs on sale nowadays are 64 bit
> - is this true?

Not at all. There's plenty of 8-, 16- and 32-bit CPUs being made
and sold these days. :)

However, pretty much any x86 hardware (i.e. PCs) you're going to
find on the market will be 64-bit.

> Anyway, I perused the Novatech barebones list and noticed that only the
> cheapest kit mentions that it's 64 bit. A quick wikipedia [1] revealed
> that (it seems) if it's a 64 bit CPU, then it'll have "64" in its title.

Not really. The Athlon64 is AMD's offering, which follows your
rule. However, Intel's Core 2 Duo and Core 2 Quad are also 64 bit. To
cover a largish swathe of the remainder, Turions (laptop/AMD), and
recent Xeon and Pentium D (Intel) processors are also 64 bit.

> I freely admit I've not kept pace (in any respect!) with modern CPUs. The
> trend now seems to be 2-4 CPUs on one chip but I don't know whether if you
> have 2 32-bit CPUs on one chip (for example) then that chip is considered
> 64 bit.

No. Fortunately, that particular piece of marketing insanity hasn't
been perpetrated yet. If it says 64 bit, it's a 64 bit CPU. Most of
the mid-range and upwards x86 processors out there come with two or
four cores at the moment.

> Can someone enlighten me? I was highly skeptical when she told me "all
> chips are 64 bit" but if she's right I'll ring back tomorrow and buy one of
> them.

Probably the main feature which still has spotty coverage is the VT
bit (Intel VT or AMD-V), which allows you to do hardware
virtualisation -- effectively giving you the ability to speed up
virtual machines (e.g. if you need to run Windows in a VM). All
current AMD processors have it, and most but not all of the current
Intel ones do, too.

To summarise:

AMD processors

Athlon64:    64-bit, 1-core, Virtualisation on Socket AM2 models
Athlon64 X2: 64-bit, 2-core, Virtualisation on Socket AM2 models
Athlon X2:   64-bit, 2-core, Virtualisation
Turion64:    64-bit, 1-core, low power
Turion64 X2: 64-bit, 2-core, low power, virtualisation.
Phenom:      64-bit, 3- or 4-core.

Intel processors:

Pentium D: 64-bit, 2-core, virtualisation on 9x0 models
Core 2 Duo: 64-bit, 2-core, virtualisation on most models, some variants low power
Core 2 Quad: 64-bit, 4-core, virtualisation on most models, some variants low power

Hugo.

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