Question How does the bios not see ram but windows does

[geoiii]

I just put one stick 8gb ddr3 ram on on a m2n68-la narra6 mobo some would argue you cant do that but my pc is kinda working.
The bios says memory not installed but it gives no error.
Windows and Linux boot just fine.
Recognize the 8 g but at slower clock speed than should be. 535 instead of 1333.
What's going on?

 

[rgd1101]

because it not supported

 

[Calvin7]

• Dual channel memory architecture
• Two DDR3 DIMM (240-pin) sockets
• Supported DIMM types:
  • PC3-8500 (DDR3-1066)
  • PC3-10600 (DDR3-1333)
• Non-ECC memory only, unbuffered
• Supports 2GB DDR2 DIMMs
• Supports up to 4 GB* on 32 bit PCs

https://support.hp.com/us-en/document/c01925534

Installing the wrong parts can give mixed results.