minimum requirement for F5 LTM VE to run

It says 2G there, so it should work with LTM only and 2G memory.

"BIG-IP

Version: 12.1.x and later Supported platforms: VMware ESXi, Linux KVM, Community Xen, Microsoft Hyper-V, Citrix XenServer, Amazon Web Services, Microsoft Azure, OpenStack Maximum Throughput: 1 Mbps Minimum disk space required: 10 GB Minimum memory required: 2 GB per vCPU Minimum processor required: 1 vCPU (up to 4 vCPUs) Max. SSL VPN Users: 10 DNS: 1000 qps"