Vista Ultimate 64bit vs 32bit

[imported_cinder]

I know with Vista 64-bit editions you can utilize more than 4GB of RAM, but what are the other benefits of the 64-bits vs 32-Bit OS (mainly Vista in general but advantages for others are welcome as well)? I also know that the 64-Bit Vista RC1 had a section that allowed for 32-bit applications but not everything can be compatible with that mode...am I right?! If it makes a difference, I will be using a Core 2 Duo as my CPU for the machine to run either the 64-bit/32-Bit Ultimate Edition of Windows Vista.

 

[Nothinman]

The only real advantage is the ability to address >4G of VM. In Windows this is reduced to 2G of VM per-process because 2G is reserved for the kernel. A 32-bit OS can easily address >4G of physical memory by using PAE, which pretty much every CPU since the Pentium has had, sadly you can't do that with 32-bit XP because MS has artificially limited it to 4G even with PAE enabled.

64-bit compatibility should only really be a problem with drivers, 32-bit apps should be able to run fine although there are other Vista incompatibilities that come into play whether or not you're running the 64-bit version so you'll have to test all of your apps for compatibility no matter what. But if you're going to be running most 32-bit apps, and if you're using Windows you will be, then there's not much of a reason to go with the 64-bit version.

 

[PaperclipGod]

Shouldn't a 64bit program run faster than its 32bit equivelent?

 

[ProviaFan]

Originally posted by: PaperclipGod
Shouldn't a 64bit program run faster than its 32bit equivelent?

Only if they can take advantage of the 64 bitness, or if they can use the extra general purpose registers. In reality, for most applications the performance improvement gained from recompiling for 64 bit OSes seems to be currently near 0%. Some media encoding apps and various scientific analysis programs are all that I've heard to benefit from being natively 64 bit.

 

[PaperclipGod]

Well that stinks. :/

Is that expected to change at all in the future? I mean, beyond the general increases in speed we always see?

 

[postmortemIA]

If there's anything in your setup that doesn't have 64-bit drivers, stick with 32-bit.

 

[Mark R]

Originally posted by: PaperclipGod
Shouldn't a 64bit program run faster than its 32bit equivelent?

It really depends on the program.

Theoretically, 64 bit programs can run more efficiently (larger work units, more CPU registers) - but for many programs, these aren't the bottlenecks.

In fact, 64 bit programs may be less efficient. Programs are slightly larger (because the CPU now needs 64 bit data to go with instructions, instead of 32), which means they use more RAM and put more stress on the RAM and CPU cache.

Overall, things tend to even out, so there's a small (few %) benefit in a program using 64 over 32. However, some heavy number-crunching programs may benefit more.

The major advantage of switching to a 64 bit OS, is the improved support for more than 2 GB of RAM. In the case of Vista, the 64 vit version also has additional security upgrades and a better variety of media CODECs (MS was not allowed to supply the most heavily DRM infested CODECs with 32 bit, due to the weaker security).

 

[PaperclipGod]

Thanks, you're damn informative. 😀

 

[aka1nas]

Also, most benchmarks are showing that the Core2Duos show less of an improvement in 64-bit mode than the K8s, so the already small performance advantage would be mostly eroded in your case. I wouldn't recommend going solely with a 64-bit OS just yet. I am still dual-booting XP Pro with Vista Ultimate 64 until the kinks are worked out.