AMD 64 Without Windows 64 = teh useless?

[Paddington]

I've been running an AMD 64 system for several months now. The performance is quite good for most applications.

I'm pretty busy these days, and I'm not as much in the know about technical stuff as I used to be. I read an article the other day that pretty much confirmed what I had guessed that you need Windows 64 to get 64 bit performance out of the AMD 64 chip. That's kind of dissapointing as Windows 64 is not an option right now because of poor driver support.

So is AMD 64 just a marketing gimmick for most of us suckers who end up buying it? 😕

 

[Maximilian]

Yea its a marketing gimmick. But 64 bit isnt really all that performance orintated, its just because soon 4GB (the maximum addressable ram on a 32bit system) wont be enough and people will need more. Hence 64 bit is born, which can address... um.. a LOT more memory.

 

[Bobthelost]

64 bit wouldn't make a blind bit of difference to me anyway, i've only got 2GB of RAM after all.

I'd tell you to search for the thread entitled "how do you explain the 64 bit to a layman" but the search engine is shite.

The short version is that if you've got 2GB or less of RAM then the improvements are somewhere between none and minimal. (It's more complicated than this, but most people wouldn't notice the difference between 64 bit and 32 bit.)

 

[Vee]

Yes, AMD64 without 64-bit OS is "useless".

As others have already said, 64-bit is about memory not so much performance.

You may see conflicting figures regarding max addressable RAM so I'll elaborate on Soviet's and Bobthelost's essentially correct answers. The limits doesn't really come from the 32-bit CPU as such. It comes from a series of smart and proper choices when building a 32-bit OS and 32-bit program model.

Strictly, with 32-bit, 4GB is the largest possible linear segment in virtual space. We could have had a segmented virtual space, but that would be a nightmare. Essentially the same as the days of 16-bit computing.

We could also have addressed more RAM, but each single application cannot. And in any case, 32-bit WindowsXP cannot use more than 4 GB ram.

Then in practice, usable memory for a single application is even less. Other things like OS resources must be mapped in somewhere in that 4GB segment. This normally leaves 2GB left for a Windows32 application. Then these 2GB becomes fragmented which means we shouldn't expect to ever be able to use all 2GB.

So if we want to have applications that can handle larger data objects we need to migrate to 64-bit. Simple as that. Don't expect 32-bit to linger for long once we get going. I don't even understand why MS bothers with a 32-bit version of Vista.

 

[Operandi]

Performance increases are small but it's only a marketing gimmick because Microsoft fails to provide a solid 64 bit OS.

 

[Madwand1]

There's a recent article that measures 32-bit and 64-bit performance across a wide variety of tests on AMD and Conroe, and even Pentium EM64T. Interesting results -- generally 64-bit builds come out a little ahead, but this varies a lot according to the specific application, as you'd expect, and some cases according to the hardware. Surprisingly, sometimes the Pentium gets the greatest benefit from 64-bit code.

http://www.xbitlabs.com/articles/cpu/display/core2duo-64bit_5.html

There are some Sandra numbers on the previous pages that sometimes show a performance degradation with 64-bit, but as the article says, these are not reliable due to differences in algorithms for differences in instruction sets.

 

[RallyMaster]

Originally posted by: Operandi
Performance increases are small but it's only a marketing gimmick because Microsoft fails to provide a solid 64 bit OS.

exactly. I've tried 64-bit WinXP Pro and it was absolutely a waste of time. half my games ran at slow-mo compared to 32-bit.