32 or 64 bit windows on a 64 bit AMD platform? Why?

December 10, 2006 6:36 PM

I bit the bullet and bought the hardware to create a cheap PC. Dual core and 64 bit with a decent upgrade path, but I digress. Now I need to know: WinXP SP2 or WinXP x64? I figure I'll "try" before I buy the latter, but to save headache and hassle I thought I might simply ask. It's basically 2007, here, folks. Should I run a 32bit OS on a 64bit platform? What are the ups and downs, the pros and cons, in your experience. Thanks!
posted by Grod to computers & internet (8 comments total)

My experience is: it doesn't matter. Computers are basically fast enough for most things I ever want to do. Running in 64 bit mode probably won't do me much good for any task I routinely try and use my computer for.
posted by aubilenon at 6:38 PM on December 10, 2006

Unless your ram needs are limited by a 32 bit system, I don't see any reason to go with WinXP x64.
posted by furtive at 6:50 PM on December 10, 2006

Routine 64-bit code is no faster, and sometimes slower, than its 32-bit equivalent. It's a big win in a few areas: crypto, some physics code, big databases, and large memory support. Of those, large memory is probably the only thing you really care about.

If you're going to expand the machine past about 3 gigs, then 64-bit is a good idea. Some operating systems will let you use more than 4 gigs in a special memory mode called PAE, but individual applications can still see only 2 gigs (or 3 with a special switch in Server 2003.) 32-bit XP flat won't support more than 4 gigs at all.

You lose some stability... 64-bit drivers tend to be less stable and usually not as fast. And you lose some backward compatibility; modern processors in 64-bit mode will no longer switch back to 16-bit mode, meaning all DOS programs stop working. (including many installers; installers were frequently 16-bit code through the early days of Windows 2000.)

If you don't care about old code, want a lot of RAM, and don't want to buy a new OS in 2 or 3 years when 64-bit goes more mainstream, then go ahead with 64-bit now. If you're not going to expand much, and you don't mind spending a couple hundred bucks in a two or three years on a new OS, then stick with 32-bit.

64-bit hurts now. 32-bit hurts in a couple years. Pain now or pain later. Your choice. :)
posted by Malor at 7:08 PM on December 10, 2006

The biggest problem I had with xp64 is that many vendors have not created 64 bit device drivers, and you can't use 32 bit drivers on 64 bit windows.

(In order to get Windows Logo certified on Vista, vendors have to supply both 32 bit and 64 bit drivers, so hopefully things will improve soon)
posted by stupidcomputernickname at 7:10 PM on December 10, 2006

WinXP x64 isn't truly a 64 bit OS, but it does use 64 bit memory addressing and can use the registers on 64 bit x86 extended chips. There's no version of WinXP 64 bit that runs on a 64 bit Power chip, or an Itanium, for example. CPU-wise, 64 bit instructions can do wicked fast floating point math, and address huge memory arrays, but WinXP 64 doesn't really break the 3 GB memory barrier, to maintain compatibility with 32 bit apps. So, it's not blindingly fast due to 64 bit tricks.

But, it finally does kill SCSIport in favor of the new StorPort internal I/O architecture from Windows 2003. If you're going to do some kind of fast disk array, StorPort is orders of magnitude better than the terribly outdated SCSIport [which has been a huge throughput limit in every NT version of Windows since Windows 3.51], in throughput, parallelism, and scalability, and I highly recommend it, as does Microsoft [click here for MS Word .doc file version of this whitepaper]. I run an 8 disk RAID50 U320 SCSI array that can transfer 327 MB/SEC sustained sequential read and about 302 sustained random write , using WinXP x64 and a MegaRAID caching controller.

That's I/O.
posted by paulsc at 7:12 PM on December 10, 2006

If you want endless problems with your computer, go with WinXP 64bit. If you just want it to work, go with WinXP SP2. The former is not mature enough yet; for example, stupidcomputernickname's comment above.
posted by intermod at 8:26 PM on December 10, 2006

paulsc: Not truely a 64bit OS? What more do you need than.. you know, using 64 bit instructions? Most apps are still going to run in 32bit mode, but that's hardly the fault of the OS. I don't see what Power or IA-64 has to do with anything.

Grod: Unless you have special needs, I'd recommend sticking with 32bit for the time being. In a Windows environment the problems you're likely to run into are almost certainly going to outweigh any benefits.
posted by Freaky at 11:46 PM on December 10, 2006

Run away from WinXP 64. I tried installing it on my new computer and had tons of driver problems. Eventually, I reverted to XP-x86, and it's been happy ever since.

If you're planning on running Vista, and you probably will want to eventually, you should look at one of the packages that lets you upgrade to Vista later for free... I think they're only bundled with hardware, though, so be wary.
posted by kdar at 6:55 AM on December 11, 2006