Before: I had 2 internal burners, 20A3P and BenQ 1625, and burns were good quality only using classic Verbs.
Today: Recently installed 2 new internal burners, 20A3P and Pioneer 115D. Moved the older internal drives to external enclosures with NEC chipset. Burned 4 diff classic verbs from diff spindles. The resulting QS was ZERO on all discs. I burned with internal drives and tested with external. Oddly, enough the QS looked similar on all scans.
Post troubleshooting: Thought it might be a PSU issue even though the external cases have their own power. I turned off both the externals and burned with the 115 and tested with 20A3P and got my 95 QS back. Furthermore, the externals scan really slow.
To Do: I currently have a 300w PSU. I planned on upgrading a long time ago, but things got in the way. I ordered an Antec 500w Earthwatt. I don't know if this will help, but it will be a good investment.
Notes: My PC randomly shut down twice in about 3 weeks. Once before I installed external cases and once after. Never happended before. I doubt I'm overloading the USB since everything has its own power supply. Might be overheating?