[FONT="]64-bit is mega-fast with 64-bit apps as well as lets you upgrade > 4GB TOTAL RAM (system RAM + graphics card + other devices). 64-bit is more secure from viruses. 64-bit also requires “MS approved” (a.k.a. digitally signed) drivers so this “might” help with hardware compatibility, etc. This is MS’s way of trying to get everyone to “move on” if they are able to.
Differences and Advantages Between 32-bit (x86) VS 64-bit (x64) Windows Vista » My Digital Life
But if you have really old programs, they might not work (esp. with 64-bit version). Google “Vista compatibility list”. Knowing a bit about computers helps getting the old problematic ones to work (Internet has a lot of solutions that smart people share).
Ultimate is the best but if you don’t think you need anything that fancy, Home Premium is good too. Get a good video card if you want Aero graphics (at least 256MB 128-bit in the newer cards)… better if you can afford. Vista technology distributes more graphics processing to the video card and relieves the CPU for other things. This is KEY to Vista performance…a good video card will make Vista work well.
Vista uses extra RAM to store commonly used files in a new activity known as “disk caching” (SuperFetch). The computer uses artificial intelligence to determine which files will be used most and copies it to RAM (where it is much faster than accessing your hard disk). This includes components of the programs you use on a regular basis. When you need more RAM for programs you launch, etc. the computer purges the “least likely used” files from RAM to make room for the new program. So in theory, the more RAM (for disk cache) you have, the faster your computer will operate. This can also be augmented (to a lesser effect) with a flash drive/card with a technology called ReadyBoost. Just stick it in and select “Speed up my system” and leave it there. Google “AnandTech ReadyBoost Performance” for basic test examples.
Understanding how SuperFetch uses RAM to enhance system performance…
Understand how SuperFetch uses RAM to enhance system performance | Microsoft Windows | TechRepublic.com
High RAM will be especially helpful for those people who like to leave all their windows open and use Vista’s “S3 sleep mode” (2 watts) so they can resume where they left off almost immediately after they turn their computers on. Your apps are pre-opened where you left them and your RAM cache is loaded too, just as if you just walked away and came back.
Vista Home Premium and Ultimate has Windows Media Center, where with a TV card/USB adapter (if not integrated) of the type that fits your TV/Cable, acts similar to TiVo. You can play your videos, schedule recordings, etc. You can get a wireless keyboard / mouse or gyro-mouse and it will be sort of like remote control. If you do this, get a big Hard Disk.
[/FONT] [FONT="]If this is any indication that 64-bit is the wave of the future and 32-bit will be “obsolete”…
There appears to be a shift taking place in the PC industry: the move from 32-bit to 64-bit PCs. [/FONT]
[FONT="]We've been tracking the change by looking at the percentage of 64-bit PCs connecting to Windows Update, and have seen a dramatic increase in recent months. The installed base of 64-bit Windows Vista PCs, as a percentage of all Windows Vista systems, has more than tripled in the U.S. in the last three months, while worldwide adoption has more than doubled during the same period. Another view shows that 20% of new Windows Vista PCs in the U.S. connecting to Windows Update in June were 64-bit PCs, up from just 3% in March. Put more simply, usage of 64-bit Windows Vista is growing much more rapidly than 32-bit. Based on current trends, this growth will accelerate as the retail channel shifts to supplying a rapidly increasing assortment of 64-bit desktops and laptops… PC Accelerators built into Windows Vista, such as Windows SuperFetch, improve performance by keeping commonly used programs in memory, even when the program is closed. More memory capacity on 64-bit PCs allows SuperFetch to do its job more efficiently.
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[FONT="]http://windowsvistablog.com/blogs/windowsvista/archive/2008/07/30/windows-vista-64-bit-today.aspx[/FONT][/FONT]
Some interesting 64-bit info:
...all 64-bit versions of Microsoft operating systems currently impose a 16 TB limit on address space and allow no more than 128 GB of physical memory due to the impracticality of having 16 TB of RAM. Processes created on Windows Vista x64 Edition are allotted 8 TB in virtual memory for user processes and 8 TB for kernel processes to create a virtual memory of 16 TB.
http://zone.ni.com/devzone/cda/tut/p/id/5709
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[/FONT] Adobe Photoshop® Extended and Acrobat® Pro natively support 64-bit editions of Windows Vista. Adobe Premiere® Pro, After Effects®, Soundbooth®, Encore®, and Adobe OnLocation™ are certified on 64-bit Windows Vista.
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[/FONT]Adobe - Adobe Creative Suite 4 Master Collection: System requirements
Adobe CS4 will be 64-bit, but only on Windows
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[/FONT]BetaNews | Adobe CS4 will be 64-bit, but only on Windows
Adobe CS4 is 64-bit only on Vista. OSX have to wait for CS5 or something like that when they catch up.
To put things in perspective, this is what 64-bit does...
What are the advantages of 64-bit computing?
In early testing of 64-bit support in Photoshop for Windows®, overall performance gains ranged from 8% to 12%. Those who work with extremely large files may realize noticeably greater gains in performance, in some cases as dramatic as ten times the previous speed. This is because 64-bit applications can address larger amounts of memory and thus result in less file swapping — one of the biggest factors that can affect data processing speed.
Adobe Photoshop CS4: FAQ
) and as Geezer mentioned, OEM is cheaper. Split the difference and go for an OEM Ultimate 
