iFixit iMac Intel 27" Mid 2010 Dual Hard Drive Kit Brand_Cleanwirth x4 configuration RAM kit is

x4 configuration RAM kit is for use in DDR4 compatible systems and operates at 2933 MT/s with an overall transfer rate of PC4-23400

pre-X99 systems

then you can still use this hub

State-of-the-art seeking algorithms and advanced power management features ensure low power consumption and long battery life

iFixit iMac Intel 27" Mid 2010 Dual Hard Drive Kit Brand_Cleanwirth x4 configuration RAM kit isiFixit iMac Intel 27" Mid 2010 Dual Hard Drive Kit Key Specifications Form Factor: Dual Hard Drive Kit Warranty: 12 months Condition: New Hack a second Hard Drive into your 27" iMac The complete kit includes all the tools and cables you need to install a second drive. Just add an iMac and new hard drive or SSD of your choice. Compatible with all processor speeds, regardless of whether or not Apple offers the additional SSD option for your machine.