After buying a new PC with Athlon 64 and hoping for some good performance gains, I decided to switch to WIN XP64 Professional. I downloaded XP64 distribution already bundled with Service Pack 2. Going through XP forums I got impression, that XP64 SP2 is a quality product with more hotfixes included inside SP2 than they in XP32 SP2 released years ago, and that should be is stable and worth of giving a try.

The battle begins...

Installation went without any problems - just like XP32 SP2 I used before. The problems started showing up right after installation - drivers.

It took me hours to find correct drivers for my MB K9N Neo Nvidia nForce 550, soundcard Realtek High Definition, printer HP PSC 1215. This was really a tough thing to do (frustrating problems with HD soundcard) and - whatsmore - for webcam Genius Messenger and USB Card Reader Manli All-in-one I have never found any XP64 drivers. Nevertheless, after 2-3 days i got my XP64 running clean & fast, even without webcam and card reader.

The battle continues...

XP64 can run also 32-bit application thanx to WOW technology (Windows32 On Windows64). System will itself recognize whether launched application will run in 32-bit or 64-bit mode and automatically adjust the environment either with WOW or without WOW support. However, NOT ALL 32-bit applications are capable of running on XP64 WOW. To my experience, about 80% of 32-bit applications will run OK with WOW, and 20% will fire system message, e.g. "Application cannot run on WOW". Of course, 32-bit aplications will not run faster on 64-bit machine. Outgoing from that, there is obviously no reason to move to XP64 unless you have your software (re)written for 64-bit processors, right? Unfortunatelly, there is still overally poor support for 64-bit applications. Software producers are aware, that costs of rewriting their software for minority of computers are too high, especially if there is WOW technology and most of their software will also run on XP64.

Let's get back to my installation - I found out, that most of software I used before moving to XP64 does not have any 64-bit alternatives, including Microsoft Office, Macromedia Dreamweaver, Flash, Fireworks, Photoshop,...etc. I did not notice almost any noteable performace gains. I also could not run SiSoft Sandra Benchmarking software (not WOW support). Good news is that all games could run perfectly with WOW, including Half Life:-)

Sudden death

Then I installed PHP environment - consisting of mySQL server, Apache and PHP IDE (NUSphere PHPEd with TechPlatform). Really bad surprise came, when I discovered nasty screen misformations in debugging mode. When I stopped at some breakpoint, the screen showed misformed output - see figures bellow.

Figures - Undocumented screen bug in WIN XP64 (probably one of many which will hardly ever be removed)

After contacting NUSphere's support I got response, that this is a XP64 related bug and they cannot do anything about it. I decided to move back to XP32 after cca 7-8 weeks.

The Winner is number 32!

Here is short overview of my experience WIN32 versus WIN64:

	Windows XP32 Home Edition	Windows XP64 Professional
DRIVERS	Mainstream - 32-bit drivers are fully supported by all producers and they will be for a couple of years.	Deadstream - 64-bit drivers are suported only for brandname hardware by biggest manufacturers. Most likely you will not be able to find all 64-bit drivers for all your hardware and peripherals. You ought to collect all drivers before you start installing XP64.
- MB, VGA	yes	Mostly supported, especially by big manufacturers with ALECAP (As Little Extra Costs As Possible:-))).
- Peripherals	yes	Guaranteed problems here! Before you start installing XP64, collect ALL 64-bit drivers for your peripherals, e.g. web-cameras, card readers, printers, scanners... etc.
SOFTWARE	Cannot run 64-bit application (sorry geeks:-)). Majority of software produced nowadays are 32-bit.	Only cca 15-20% of 32-bit software has been rewritten for 64-bit platforms. (too high extra costs for producers for rewriting 32-bit applications for 64-bit platforms as they must maintain both 32 + 64 bit variations). Luckilly, thanks to WOW, XP64 can run 80% of 32-bit applications even though with no performance gain. Some 32-bit applications running on WOW appears to be actually slower (e.g. Apache2 server) or will throw error message *Cannot run on 64-bit platform* or will simply crash.
- availability	No problems with finding any software needed.	Problems with finding some important applications for XP64 - e.g. I could not find virtual disks (Nero ImageDrive not working, Paragon Emulator not working..).
- support	Regular hotfixes & updates will continue probably for another few years.	No official support for XP 64, means almost no bugfixes/hotfixes. This means I could not hope to solve problem with ugly screen in debug mode (see above).
- stability	With installed XP32 Service Pack 3 I dare to say, that XP32 became pretty stable OS.	Stable, no crashes experienced - with exception of installing incompatible drivers at the begin.
- performace	XP32 installed on 64-bit processor will run as fast as being installed on 32-bit processor. Unusable (unfortunatelly) performance reserve.	64-bit applications will gain some performance boost about10-30% depending on particular HW configuration. 32-bit applications will not gain any performance or slow slightly down running in WOW mode.

Defeated with honour

I truly regreted that i must move from XP64 back to XP32. Apart from the problems with drivers availability (and some occassionally useful software, e.g. virtual drives), system appeared stable and everything worked fine. Also almost all software I needed was running without bigger problems. Unfortunatelly, after few weeks I realized that almost every day I may experience some problem resulting from 32/64-bit software incompatabilities, software availability and also that some pieces of my hardware may never get running. Simply keeping on with XP64 has no real future - there will always be "little unpleasantnesses" to deal with. Especially now, when Microsoft fianlly released (most likely) final Service Pack 3 for XP 32 - it is actually safer to stay with commercially still supported distribution of XP32.

Ah, one last word - why I did not mention about Windows Vista as possible alternative to XP64 - simply Vista is at this time (2008) not serious competitor for XP32 (with SP3). Considering life cycle of a product, Windows Vista is still a baby product which may become mature perhaps in another 1-2 years, hopefully, with release of Service Pack 1 or 2.

* * * [2008-April-20] * * *