Windows 8 and wmc 32 or 64 bit does it matter?

I would say these days it doesn't really matter. There's a gradual move to x64 (many were surprised Windows 8 had a 32-bit version at all), and 64-bit driver support has now matured enough that there shouldn't be any issues. My Windows 7 HTPC is still x86, but if I was to rebuild again at the moment, I'd probably go x64.

I just rebuilt my computer and installed Windows 7 64 bit. Windows 7 sets up two program files directories, one for 64 bit programs and one for 32 bit programs. I don't know about Windows 8.

X64 if using more than 4 gb memory, other wise no real diff.

Ceton recommends 4GB of ram, so if you are using their card, it may make sense to go x64. I didn't see any difference between running x86 with 2GB vs x64 with 4GB in terms of recording or watching live TV.

the software has to be native x64 code to see improvements and it's only a 10-15% improvement. otherwise, it just let's you use more of your RAM. With x86 (32-bit), you're limited to 4GB of address space. that means a TOTAL of 4 GB for everything you own. That means if you have a 1 GB graphics card and 4 GB of RAM, you'll only see 3 GB of RAM because 32-bit can only recognize 4 GB total. There are ways around the 32-bit limitation (read: PAE) but it's just easier and better to go to a 64-bit OS.

then you factor how software factors into this address space and 32-bit because a real problem. On 32-bit Windows, in normal configurations, each program only has a usable address space of about 2GB, half of the total memory that can be addressed with 32-bit addresses. This means that the amount of RAM that the program can manipulate directly is limited to 2GB. If the program needs to work on a larger chunk of data, it has to move that data in and out of RAM a piece at a time, usually storing it on disk when it's not in RAM. This 2GB limit is regardless of the amount of physical memory installed; if you run multiple programs, they each get a 2GB block of their own, so they can use many gigabytes in total, but any individual program can't readily break through this limit.

another thing is 64-bit code is more secure. there's malicious code that's designed to fill up the address space and execute. that's many times easier to fill up the space of a 32-bit system due to the very very small address space. unfortunately, as long as you're running 32-bit software on your system, as long as the exploit can take advantage of that particular software, you have a vulnerability there. but it's a 1-to-1 exploit. so if some malware guy writes something to target 32-bit Adobe Acrobat Reader but you don't have that program, it doesn't matter.

most software is still 32-bit, including most TV software. If you move on to more complicated software like video editors, many of them like Adobe Premiere ONLY have a 64-bit version.

there's really no point in installing a 32-bit OS at this point, especially since the 64-bit version can run 32-bit software. the only time you need a 32-bit OS is if there's a particular hardware device you own that has no driver in the 64-bit OS and it's such a legacy device that the company has not made a driver for it. that said, a lot of old devices still have drivers that'll work.
Edited by onlysublime - 12/25/12 at 10:59am

I've been using 64-bit for years, and never did have a problem that I could trace to it. Now that all new CPUs are 64-bit and 2 x 4gb memory stick pairs can be had for $40 or less, I don't see a point in using 32-bit for a new build.

At this point I think you'll encounter more issues going with 32-bit, mainly upgrading the ram of course.

FWIW, I'm using a pair of AverMedia Duet cards with Windows 7 64 bit & WMC7 and they are working great.