Question Is this vintage CPU 32 or 64 bit?

[ManOfArc]

As I posted in an earlier thread, I put together a retro build. I've come across another ancient CPU that is marked just Pentium 4. It's 3Ghz with a 1M cache. But there were several Pentium 4s back then, weren't there? Is this the correct one? Link
If so, it is 32 bit. My present CPU (Pentium 4 640) is 64 bit. Motherboard is MSI P6N SLI Platinum Series. Assuming that is the correct CPU, will a 32 bit processor work on my motherboard?

 

[ManOfArc]

I forgot to show the CPU
Link

 

[CountMike]

I forgot to show the CPU
Link

32bit.
https://ark.intel.com/content/www/u...rocessor-2-80-ghz-512k-cache-533-mhz-fsb.html

 

[ManOfArc]

32bit.
https://ark.intel.com/content/www/u...rocessor-2-80-ghz-512k-cache-533-mhz-fsb.html

Thank you, but I'm not sure your link is the one I have. On my CPU's heat shield it references a 1M cache (if I'm interpreting that nomenclature correctly) Your link refers to a 512MB cache. But I tend to agree with you about it being 32 bit.

 

[CountMike]

Thank you, but I'm not sure your link is the one I have. On my CPU's heat shield it references a 1M cache (if I'm interpreting that nomenclature correctly) Your link refers to a 512MB cache. But I tend to agree with you about it being 32 bit.

As far as I know, first Intel 64 bit CPUs were "Core" designation which came after

 

[BFG-9000]

From the picture it is a model 530J which is apparently 32-bit but oddly with Execute Disable Bit (XD/NX-bit), while 531 which is also 3GHz added the 64-bit capability. It would probably work in your motherboard but 530J is not on the officially supported list while 531 is. In any case you don't need a 32-bit processor to run a 32-bit OS, 64-bit processors work fine.

Technically, 90nm Prescott all included the EM64T instructions but it was disabled in all the 1M L2 cache models except 5x1, 517, 524 models. The 2M L2 cache models N0 stepping and later for desktops also support 64-bit (P4 HT 620, 630, 640, 650, 660, 662, 670, 672). All of the 65nm Cedar Mill CPUs support 64-bit and have 2MB L2 cache (P4 HT 631, 641, 651, 661)

All of the "Pentium D" dual-core Pentium 4 including 90nm Smithfield (2 x 1MB L2 cache) and 65nm Presler (2 x 2MB L2 cache) appear to support 64-bit.

Note this is fine for running XP-64 or 64-bit Win 7 or even Win 8 as all have XD/NX-bit + CMPXCHG16b, but as far as I'm aware only the 65nm models have PREFETCHh/PrefetchW and LAHF/SAHF for 64-bit Win 8.1 and Win 10

Your board does support Presler but I don't why you'd bother when it also supports Core 2 Duo and related Pentium Dual-Core CPUs, which are way faster in games and by now the same price of almost free + shipping. Pentium 4 architecture required special compilers to perform at its best and no software uses those kinds of optimizations anymore.

 

[Nice Nicer]

As far as I know, first Intel 64 bit CPUs were "Core" designation which came after

I also think so, even some core2duo processors we're still 32 bit, If i remember correctltly.

 

[ManOfArc]

From the picture it is a model 530J which is apparently 32-bit but oddly with Execute Disable Bit (XD/NX-bit), while 531 which is also 3GHz added the 64-bit capability. It would probably work in your motherboard but 530J is not on the officially supported list while 531 is. In any case you don't need a 32-bit processor to run a 32-bit OS, 64-bit processors work fine.

Technically, 90nm Prescott all included the EM64T instructions but it was disabled in all the 1M L2 cache models except 5x1, 517, 524 models. The 2M L2 cache models N0 stepping and later for desktops also support 64-bit (P4 HT 620, 630, 640, 650, 660, 662, 670, 672). All of the 65nm Cedar Mill CPUs support 64-bit and have 2MB L2 cache (P4 HT 631, 641, 651, 661)

All of the "Pentium D" dual-core Pentium 4 including 90nm Smithfield (2 x 1MB L2 cache) and 65nm Presler (2 x 2MB L2 cache) appear to support 64-bit.

Note this is fine for running XP-64 or 64-bit Win 7 or even Win 8 as all have XD/NX-bit + CMPXCHG16b, but as far as I'm aware only the 65nm models have PREFETCHh/PrefetchW and LAHF/SAHF for 64-bit Win 8.1 and Win 10

Your board does support Presler but I don't why you'd bother when it also supports Core 2 Duo and related Pentium Dual-Core CPUs, which are way faster in games and by now the same price of almost free + shipping. Pentium 4 architecture required special compilers to perform at its best and no software uses those kinds of optimizations anymore.

Thank you. I felt too, that it was the oddball 530J, and that it was 32 bit. That confirms it for me. Wow, 90nm! How far they've come since then. And thanks for confirming the board will work with it.