​If opera is running slow on PC try doing this on the systems (will need done on every PC if it works)

Open Network and sharing centre
click on 'Change adapter settings'
Right click on NIC and select 'Properties'
Select 'Configure' for NIC and click on the Advanced tab
Disabled the following;
Interrupt Moderation
IPv4 Checksum Offload
Large Send Offload V2 (IPv4)
Large Send Offload V2 (IPv6)
TCP Checksum Offload (IPv4)
TCP Checksum Offload (IPv6)
UDP Checksum Offload (IPv4)
UDP Checksum Offload (IPv6)

If you can not find these you can edit via regedit;
"HKLM\System\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}\00<Index>

Run Command Prompt as Administrator
Run "netsh int tcp set global chimney=disabled"
Restart computer