Question MB "X10QBL" started up but freezed at boot message "System Initializing ..." with POST code “AF”. I have Intel QEFU E7-4890 v2 processor, also tried Samsung & Qimonda memory pairs, but got the same failure. Please advise. Answer According to Intel ARK database, this CPU “QEFU” is C0 stepping engineer version, not the production processor. Our official BIOS did not support "ES" (Engineering Sample) CPU. Please switch your CPU to production version. Was this FAQ helpful? YES      NO Enter Comments Below: Note: Your comments/feedback should be limited to this FAQ only. For technical support, please send an email to support@supermicro.com.  Enter your email address below if you'd like technical support staff to reply:  Please type the Captcha (no space) V T M B FAQ Stats FAQ ID Related Category / Keyword Date Posted Code 21616 Peripherals: - CPU 09/23/15     Print Answer