Even though server have 3 PCIe slot on 2 of the slot support NVMe PCIe SSD. If you refer the link I provided NVMe HHHL card are supported only in slot 1 and 3 in "Riser configurations: 1A + 2A"
Hello I have rack server power edge R640 with the below specifications Chassis with Up to 10x2.5in HDD and 3 PCIe Slots PCIe Riser Config 4, 2 x16 Low Profile 240GB SSD SATA M.2 512e 6Gbps Drive My question, How many NVMe PCIe device I can add? Please note that server is running in production and I cannot access it since it is abroad, so I have to take the correct decision 
How many NVMe PCIe can I install