My question could be silly, but I haven't found confirmations on the topic
Does using a TPM improve Windows BitLocker's performance than relying only on PIN/USB/token authentication?
In my case I need to change motherboard to get TPM support, but I won't change the CPU, which is an AMD Phenom II.
To my recollection the answer should be a plain NO because the TPM acts only as cryptographic storage of keys and cryptographic operations on the disk's data is done by the CPU with performance based on hardware encryption acceleration.
That would mean the performance downgrade depends on the ability of the Phenom (or any other CPU) to perform ciphering fast.
This question is not obviously about security. And pre-boot authentication delay (e.g. the time to type the PIN) does not count as performance to me.