BitLocker encrypts the entire hard drive. I run Visual Studio and build projects much of my day. How much will BitLocker slow me down (dual core laptop with 3 GB of RAM)?
MaximumPC ran a few tests:
However, when we busted out the hard-drive-intensive benches, we immediately saw as much as a 20 percent hit on the encrypted system. We're not sure the PCMark06 slowdown represents real-world performance, but our Photoshop script, which includes tons of hard-drive-intensive reverts, showed a 10 percent hit as well.
What's the bottom line? We're not going to enable BitLocker on systems that don't hold crucial, mission-critical data.
Benchmark (Unencrypted Drive; Encrypted Drive):
FEAR (FPS); 56; 57
3dMark06; 8071; 8082
PCMark06 Hard Drive Suite; 6133; 4948
Photoshop CS Script (Sec); 303; 330
Sure, running 3D benchmarks doesn't really make sense as you're hardly going to encrypt a gaming rig, but in the end it's simple trade-off: performance for security.