I was debating setting up encryption on my computer and was wondering if anyone has had any experience with this hindering performance? My machine is built almost completely around gaming, graphic design, and working with schematics and such, so I prefer not to have any degrade in performance.

If BitLocker does cause some performance issues, are there any alternatives out there that don't work against performance?

Personal data, yes by all means.
Other than that it will hamper performance and it's not really needed..

Depending on your machine, Microsoft says Bitlocker can take a few percentage points hit in performance.
[http://technet.microsoft.com/en-us/library/ee449438%28WS.10%29.aspx#BKMK_Performance]

Based on a few benchmarks, (easily searchable), there is a variation between 10~20% in synthetic benchmarking. (this could translate to a slightly slower machine in some intensive operations, such as Photoshop).

There are other encryption suits out there, notably TrueCrypt. (I've read anywhere between them saying it is slower than BitLocker to being faster).

Thanks for the feedback, both of you.

I know I could search for what others experience, but I'm looking for some feedback from users on this forum.

There's a few reasons I'm looking into encryption, but the main one is that I'm paranoid. Haha. I'm interested in setting it up so that if I lose my password/passphrase, the data is lost as well and completely unrecoverable (even with known-plaintext attacks).