You can run BitLocker without a TPM chip. The TPM basically functions as a unique hardware key so that "secured" data/drives cannot be decrypted on other platforms. It's not really of much use to most consumers because chances are you'll lose your BitLocked data one of two ways:
1) the computer is physically destroyed or stolen - along with all your encrypted data and the TPM key needed to decrypt it. You may have off-site backups somewhere (in the cloud, discs, flash drives, etc) but they cannot be decrypted/recovered without the TPM key.
2) the BitLocker drives/volumes/data somehow crash or get corrupted. You can only attempt recovery/decryption on the computer with the TPM installed, not any other machine (with or without the TPM), and this might be a catastrophic pain if your computer just won't work. (Normally, one can always attempt data recovery by transferring the drive into another machine and working off cloned images.)
From what I've read, not all ASUS ROG motherboards have "proper" TPM support in BIOS. I can't confirm this, I've only used a TPM in an R5E as a unique "hardware identity dongle" for running certain professional software packages. I just cold booted and found some TPM options suddenly listed in BIOS settings, I don't bother to use it for BitLocker because (as mentioned above) being locked onto a single (and likely malfunctional) computer makes data recovery a serious pain - also, "my" sensitive data is in fact "my employer's" sensitive data, it does me and my employer no good while sitting at my home and BitLocker is "secure" enough and constant decrypt/encrypt cycles involving my TPM key add up to a serious waste of time.
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[/Korth]