First off, yes your video card should handle the visualizer better than you see it in the videos.
Secondly, I was referring to your version of Vista, not your processor. On the Vista DVD, you are supplied the 32 bit and 64 bit versions, you get to choose which one to install (since you have a 64 bit processor). I'm not sure which version they would preload on your computer, you should check with Dell on that point. Here is a third party explanation of the issue, point number 2 is the problem I was referring to earlier:
Taken From
http://www.tech-recipes.com/rx/1426/vista_64_bit_or_32_bit_version_x64_vs_x86 Deciding which Vista version to install can be a difficult decision and can really limit what you can do with your system. Here are practical hints which should help a user decide which version to install. I decided to write this guide after installing 64-bit and 32-bit vista systems on several test boxes.
With the gaining popularity of 64-bit chipsets/processors, many users now have the ability to run either 64-bit versions (x64) or 32-bit versions (x86) of software and operating systems. However, if you only have a 32-bit processor, your choice is easy...
You can only install the x64 version of Vista if you have a 64-bit processor.
For those with 64-bit processors, it seems obvious that installing the x64 version of vista would be ideal. The x64 version has increased security based around the 64-bit structure and programs compiled for 64-bit processors will likely run faster.
What's the problem with installing Vista x64 on a 64-bit system?
1. Most hardware does not currently have 64-bit drivers.
Out of all the boxes that I have installed x64 Vista on, I could always get it to boot up. However, the lack of 64-bit drivers for many hardware devices typically left me without any chance of burning DVDs or listening to audio. Networking devices and card readers were frequently not supported as well. Vista x64 is pretty but it's not very fun without network access or audio.
2. In Vista x64, any driver that is not properly signed will not be able to enter the kernel and will fail to load.
Think how many times you have ignored that warning that a certain hardware driver is not properly signed. With vista x64, if your driver has not be blessed by Microsoft, it will not work. Forget about it.
I have tired to get around this by booting with the F8 option Disable Driver Signature. It doesn't make a difference.
3. Vista x64 currently does not backward support most x86 (32-bit) drivers.
For the most part 64-bit systems run 32-bit applications very well. However, vista x64 doesn't run x86 drivers... at least at this stage.
4. Vista x64 does not support 16-bit software.
You may think that you never, ever run 16-bit software. However, XP actually handles this legacy fairly well.
5. Very little x64 software currently exists.
x64 software runs better on a x64 system with an x64 OS. Currently, however, there is very little x64 software out there. If you have that magical combination, you do get a nice performance boost. Currently, however, this combination is way to far ahead of the curve.
Conclusion:
Most users with 64-bit hardware should install the 32-bit (x86) version of Vista.
Vista x64 is the turning point for operating systems as they transition to 64-bit. Currently, however, the majority of users will be very disappointed by installing Vista x64. The lack of 64-bit drivers for most current hardware will be very disappointing and frustrating to most users. Why push for 64-bit now anyway? The performance gains promised by 64-bit will not be seen for years until 64-bit compiled versions of software is the norm.