ASUS Servers use Low Profile PCI slot (Butterfly Raiser Card) for adding RAID controllers. Based on the server model, this particular slot will be associated with either CPU 1 or CPU 2. It’s important to check the Server user manual to understand this information. Following illustrates two Server model examples
Example
1: ASUS RS700-E10-RS4U
Below is a snippet of System specifications Table from Server User manual. It’s clear that the RAID controller slot belongs to CPU 1. Hence RAID controllers can be added even in single CPU populated configuration scenarios
Document link: E22686_RS700-E10-RS4U_UM_V3_WEB.pdf (asus.com)
Example
2: ASUS RS700-E11-RS4U
As per the
system specification, RAID controller slot of this particular server model
belongs to CPU2. This means RAID controller will not supported in a single CPU
populated server configuration.
Document link: E22378_RS700-E11-RS4U_UM_V2_WEB.pdf (asus.com)
Therefore, it's always a good idea to refer the system specifications of the server you plan to configure. Alternatively, a single-socket server option can be recommended if it meets the requirements.