diff --git a/hardware.md b/hardware.md
index 0609b6f..53688dd 100644
--- a/hardware.md
+++ b/hardware.md
@@ -23,6 +23,18 @@
 - Boot storage/media
     - If you are using USB stick, make sure it is geniune/not fake. You can check that by: ValiDrive https://www.grc.com/validrive.htm , best one is H2testw https://h2testw.org/
 
+## HP Gen9 servers bug (single core only)
+
+Some HP servers might not detect all CPU cores, and show only one, then you need to do changes in BIOS:
+
+1. F9 to enter the BIOS
+2. Go to System Configuration
+3. Go to BIOS/Platform Configuration (RBSU)
+4. Go to Processor Options
+5. Go to Processor x2APIC Support
+6. Select Disable
+
+
 ## How to verify PCIe slot
 
 If you install card in 4x lane PCIe slot, while card designed for 8x PCIe, most likely your card wont be able to reach max bandwidth and will drop packets due PCIe bus bandwidth limit.