Hello, before you can actually determine that the problem is the chipset, I recommend you to try with a different DVD burner.
For the problem with the transfer rates, how are you measuring them?
To be able to assist you better, we will need more information regarding your system like the power supply and RAM memory.
I installed another dvd burner sony DRU-870 ,but it also does the same some time burns some time not.i finally found the the solution
1-unistall intel desktop utils
2-unistall both IDE ATA?ATAPI CONTROLLER
and install windows standard controller and now my hp burner start burning dvds and hard drive to hard drive copying process is fast now.