LG GSA-H10A can't burn faster than 2x

i got a LG GSA-H10A on my system which is:

AMD Sempron 2800+ 64-bit
Asrock K8-Upgrade VM800
Seagate SATA-150 (80GB)
512 GB Memory

it took like 15 min to burn a 1.5 GB DVD iso Image. can someone please help me. :o

Enable DMA. Provide more info about the media, the burnspeed and software used.

DMA is Enabled, i am trying to burn at 8x, and i am using windows xp x64 and nero

Using Nero CD Speed (http://www.cdspeed2000.com or if you already have Nero installed on your system, CD speed will be installed already as part of it), place a DVD disc which you have already written to (non-blank) and run a burst rate test. Post the results here.

How is your H10A connected to your system? As in which IDE cable, primary or secondary; is there any other device sharing the cable with your H10A? And if so, what is that device?