For me RCU is performing perfectly as normal! Although recently I had a problem as described below....

My PC picked up a virus, which was not picked up by my virus check scan and automatically deleted or quantined. It was a file dumper trojan that was uploading god knows what onto the internet. It really slowed by PC down until I got rid of it. I found it by looking at the upload and download speed when the PC is idle. It was running 400kb/s upload! Found the relevant .exe files by threat checking system files (with low risk threshold) with my Virus software (Nod32 - brilliant), and manually deleting.