Is my Core2 Duo 64bit?

I have heard that some core 2 Duo chips are able to handle 64 bit OSes. I have just received a wiped (clean hard drive) Dell Optiplex 745 (Small Form) from work.

  1. How can I tell if it can handle a 64 bit OS or not?
  2. Is there a performance hit, or any down-side to using 64-bit instead of a 32-bit on this level of machine (as opposed to the in
    chips)? 1. Is there a memory cut-off with the 32 bit that doesn’t exist with 64 bit? This machine can, theoretically, handle up to 8 GB of RAM (it has 2GB) but that doesn’t do much good unless the OS can also handle that much RAM.

I did find a spec sheet on it here : http://www.dell.com/downloads/global/products/optix/en/opti_745techspecs.pdf if that helps.

I am planning on making this my primary desktop, since my current desktop is a Pentium 4.

  1. AFAIK Core 2 Duo’s are 64bit. To test: try booting from a 64bit LiveCD or a DVD. It will tell you soon enough it can’t run.
  2. Performance hit: theoretically yes, the architecture allows a double bandwith for internal datatransport. I had a 32bit install on my server/workstation, not much difference, except for rendering, videoconversion. My personal point of view: if a machine can do 64bit, it will do 64bit.
  3. Yes there is. 32bit is limited to 3GB max. But …there is kernel-desktop (optimized, PAE enabled) and kernel-pae (kernel-default but PAE enabled). PAE makes RAM > 3GB accesible.

Thanks for the quick response!

I was hoping there was a way to determine if it could run 64-bit without having to download an entire LiveCD :slight_smile: I have plenty of 32-bit LiveCDs to try.

I wasn’t sure since this would be one of the earlier 64-bit chips available, whether there would be a more significant hit that newer chips handle with power to spare. Unless 64-bit chips were out beforehand longer than I thought?

Is a 64-bit OS limited in how much RAM it can handle, and is that true for all OSs? I may take this system and dual-boot between openSUSE 12.1 and Windows 7 and it would suck if one can see all 8 GB and the other can’t!

Run on a 32bit live cd


grep lm /proc/cpuinfo

If the lm (Long Mode) flag is there then it means that the CPU is 64bit.

Awesome! I’ll try this when I get it home tonight!

If I knew I was going to get it today, I would have brought a LiveCD with me to play with it but I only knew I was going to get something by Friday. As I was wiping the hard drive off the Pentium IIIs I prayed those weren’t going to be the ones I got! :open_mouth: I’m thankful I got this one, plus it is the only one with a DVD & CD-RW!

All core2 processors are 64 bit.

Core 2 Duo “Allendale”](Conroe (microprocessor) - Wikipedia), “Conroe”](Conroe (microprocessor) - Wikipedia) (65 nm)

source

dragonbite wrote:

> have heard that some core 2 Duo chips are able to handle 64 bit
Yes

what is

cat /proc/cpuinfo

On 05/31/2012 04:16 AM, dragonbite wrote:
>
> I have heard that some core 2 Duo chips are able to handle 64 bit OSes.
> I have just received a wiped (clean hard drive) Dell Optiplex 745 (Small
> Form) from work.
>
> - How can I tell if it can handle a 64 bit OS or not?
> - Is there a performance hit, or any down-side to using 64-bit
> instead of a 32-bit on this level of machine (as opposed to the i-n-
> chips)?
> - Is there a memory cut-off with the 32 bit that doesn’t exist with
> 64 bit? This machine can, theoretically, handle up to 8 GB of RAM (it
> has 2GB) but that doesn’t do much good unless the OS can also handle
> that much RAM.
>
>
> I did find a spec sheet on it here : http://tinyurl.com/26g3nx if that
> helps.
>
> I am planning on making this my primary desktop, since my current
> desktop is a Pentium 4.
>
>

The optiplex 745 is a 64 bit machine through and through. I ran 64 bit
openSUSE on it for a year some time ago, nice machine.

[currently got an optiplex 755 and an optiplex 960 in my office, they’re
nice 64 bit boxes too]


Regards
swerdna

I realized the promotional openSUSE 11.4 DVD I got a while back had a 32-bit side and a 64-bit side so it was easy to give the 64-bit version a whirl and it worked great! Now I have to decide whether to get a bigger hard drive first, or just jump right in and migrate things over later.

Impatience can be a PITA :wink:

On 05/31/2012 10:56 PM, dragonbite wrote:
>
> I realized the promotional openSUSE 11.4 DVD I got a while back had a
> 32-bit side and a 64-bit side so it was easy to give the 64-bit version
> a whirl and it worked great! Now I have to decide whether to get a
> bigger hard drive first, or just jump right in and migrate things over
> later.
>
> Impatience can be a PITA :wink:
>
>

I gave mine 8Gb of ram and initially an 80 Gb hard drive. Later I
changed that to 500Gb so I could store multimedia files and virtual
macuines. But I don’t know of any need to enlarge disk space just
because you change from 32 bit to 64 bit.

Regards
swerdna