Slow performance on FlashBackup Windows restore

Hello Everybody!!

I am running backups on a physical server windows client server with a lot of little files on three filesystem drive. The backup is configured as flashbackup because the backup window is restricted and the amount of information is 3TB per filesystem.

The backup is running with multistream. During backup the throughput is 45MB/sec. 

When restoring the throughput is 3MB/s. I have setted up the NUMBER_DATA_BUFFERS, NUMBER_DATA_BUFFERS_RESTORE,  SIZE_DATA_BUFFERS, NET_BUFFER_SZ. There is no performance improvement.

Also the activity monitor does not reflect any change. The bptm log shows io_init: buffer size for read is 262144.