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Dual Core or 64 bit?

Posted: Wed Nov 16, 2005 3:22 pm
by dd
Not sure if this is the correct place for this question:

Which is best: Dual core or 64 bit?

Am thinking about getting a desktop and would like to know which is the best option.

Many thanks

Posted: Wed Nov 16, 2005 5:04 pm
by a31pguy
IMHO - Dual Core. Very few applications for windows run native 64-bit apps unless they're compile for it even when the OS is running in 64-bit mode. Unless your peforming numerical analysis apps and absolutely need 64-bit registers.

Dual Cores is better since you can multi-thread processes. Tasks can be assigned to seperate virtual CPUs. With a dual-core Prescott - you can have four virtual CPUs.

AMD QuadCore?

Posted: Thu Nov 17, 2005 1:58 pm
by BigWarpGuy
I read that AMD is working toward a QuadCore chip.

Posted: Thu Nov 17, 2005 5:51 pm
by a31pguy
can you say mandatory water cooling?

Re: Dual Core or 64 bit?

Posted: Thu Nov 17, 2005 11:06 pm
by K. Eng
Your question is kind of moot. In desktop platforms, all dual core processors are 64-bit.

Intel Pentium D and AMD Athlon 64 X2 are both 64-bit processors. The dual core G5s used in Apple's final PPC based PowerMac are also 64-bit processors.
dd wrote:Not sure if this is the correct place for this question:

Which is best: Dual core or 64 bit?

Am thinking about getting a desktop and would like to know which is the best option.

Many thanks

Posted: Fri Nov 18, 2005 1:09 pm
by a31pguy
True,

All Pentium platforms are internally 64-bit registers - but not 64-bit bus. Sun Sparcs were 64-bit (but until Solaris 7+ were not 64-bit OS). Even after solaris 7, applications needed to be compiled to 64-bit. But the operating systems and applications which run on them are 32-bit.

This reminds me of the DEC Alpha vs. Intel days. Personally - if I were in the mood for a new architecture - I would look at the AMD Opteron CPUs. From some of the trade journals I've been reading, there are some very interesting architectures coming from AMD.

Posted: Sat Nov 19, 2005 1:18 am
by K. Eng
I don't think this is exactly true... the Front Side Bus width since the original Pentium has been 64-bits. This is simply the width of the processor interface, and doesn't have anything to do with memory address space.

x86 registers are 32 bits for integer/GPR and 80 bits for x87 FPU, longer I think for SSE/2 registers.

Pentiums that implement x64 have 64 bit registers for integer/ALU, and a few extra GPRs.
a31pguy wrote:True,

All Pentium platforms are internally 64-bit registers - but not 64-bit bus.

Posted: Sat Nov 19, 2005 7:54 pm
by a31pguy
agreed - but the PCI slots are still 32-bits, with some exceptions for PCI-64-bit slots, PCI-E, and AGP. But in previous models there have been very few 64-bit PCI cards and even fewer 64-bit drivers.

SSE2 and SSE3 are 128-bit. But only in the CPUs that support SSE2 and SSE3.

But it's still not 64-bit applications. The windows operating system is still 32-bit. There are some versions of windows server that are 64-bit - however even fewer 64-bit applications have been compiled for them.

The intel 64-bit server CPUs have been a dismal failure and windows server 64-bit OS have not been widely adapted.

About the only true 64-bit applications I have seen are on the UNIX side of the house. DEC had some following - but since the HP/Compaq buyout - the only remaining 64-bit applications I have seen are in Solaris 10 with specially compiled 64-bit applications. The problem is that most software design houses only see limited markets for 64-bit apps and don't want to support both a 32-bit version and a 64-bit version.

Posted: Mon Nov 21, 2005 2:46 pm
by Esben
I can't see a heatproblem with quad core Athlon64. The current power-champ of AMD is the Turion MT-40, at 2.2 GHz, using 25W. Take four of these, and put them on the same die. 25Wx4 = 100W, still less than P4 Prescott.

In 2007, at 65nm, my estimate is a quad-core 2 GHz Athlon64 will use app. 75W.