Thanks for clarifying - great info here! -----Original Message----- From: Ben Scott [mailto:mailvor...@gmail.com] Sent: Monday, March 30, 2009 2:28 PM To: NT System Admin Issues Subject: Re: Running 32bit OS on 64bit hardware
I didn't get the OP for some reason, so I'm replying to replies to get the OP... sorry for any thread tangling... * David Mazzaccaro <david.mazzacc...@hudsonhhc.com> wrote: > Are there any ramifications with running XP 32bit on this 64bit hardware? Many -- if not most -- of the x86-compatible processors sold within the past several years support long mode (the 64-bit x86 extension introduced by AMD in 2000). So it would actually be rather hard to find hardware that *isn't* "64-bit" in some way. In other words, you're already doing it, you just didn't know. :-) > Will he see any performance downgrade? Meaning, if Win XP 64-bit was installed instead, would the system run faster? Maybe. It depends on how the system's being used. If it's only being used to surf the web and write email, the user will likely never notice a few extra gigs of RAM. If the user only ever does one thing at a time, it's also unlikely to make a difference: Win64 can use more than 4 GiB of RAM, but most applications are still only 32-bit, and thus limited to 2 GiB [sic]. Long mode mainly benefits people looking to run significant multi-processing workloads (more processes means more things using RAM), or processes working with datasets larger than 2 or 3 GiB and written to take advantage of a 64-bit virtual address space. CAD/CAM, scientific models, GIS, video editing, some of the latest games, that sort of thing. That said, if you're mainly running modern, well-behaved applications drivers, running Win32 processes on a Win64 OS typically doesn't cause any problems. If all your hardware also has drivers for Win64, there's little reason to limit yourself to Win32. There is old and/or badly written software which gets upset about Win64, and/or hardware which doesn't have Win64 drivers, but if it's an all-new home computer, those things are a lot less likely to be a problem. > Would he be better off with only 3GB of RAM? > But is it a bad thing to have a system with 6GB of ram when the OS is > only seeing and using ~3GB? Win XP will not use hardware address space above the 4 GiB mark. Further, various things that aren't RAM have to appear in that 4 GIB space. So Win XP 32-bit will ignore a significant chunk of that 6 GiB of RAM. (Exactly how much depends on what hardware is in the machine. Around 3.5 GiB RAM seems to be the practical maximum, and 3.1 GiB or less is not uncommon.) It won't hurt the software to have hardware it's not using. But it's kind of a waste of money, unless you plan to upgrade to Win64 some day. Might waste some energy. Tends to upset people who feel the size of their RAM reflects the size of the sex organs. (You laugh, but I've seen countless l33t hack3rs switch to Win64 *ONLY* to get that number to be bigger.) I'll also mention that just about every x86 processor made in the past decade can address more than 4 GiB of RAM, even in 32-bit Protected Mode. It's called PAE. Some 32-bit Microsoft OSes -- the "Advanced Server" flavors -- will use it. So will most Linux distributions. Win 2000 Pro, Win XP, and Win Vista refuse to use addresses above 4 GiB solely because many drivers (including ones shipped "in-box" by Microsoft) puke if they see a hardware address above 4 GiB. -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
