Expected Speed/Throughput on APM SSL VPN

Anyone have vpn configured with APM? I can't find anything on throughput speed limitations. I am seeing terrible speeds in relation to actual link speed when going through the VPN. We have a 1GB network wire. When transferring files via WinScp over the VPN on the LOCAL network I am seeing client to server speeds around 600 to 900 KiBs. When I bypass the VPN Im getting 900Mbits/sec. Now I know that there is overhead but is there that much overhead? Is this expected performance? I have tried everything including stripping down the VIP to no auth, performance profiles, DTLS...etc. I have checked license limitations as well. I have tried tweaking the TCP profiles to up the windows and buffers but this doesnt seem to make any difference. The capture doesnt show the tcp sliding window factor but it seems like the F5 is choking on the data when transferring or its telling the client not to dump so much data on the wire. If this is the case then fine but I cant find any explanation out there. What do your speeds look like? I have tested internally from client>switch>firewall>bigip>switch>server on a local lan and the speeds are around 6-9Mbits.