New Harddisk I bought..how to differentiate?

[ghosty]

Hi all
I just got myself a new harddisk...I told the guy that the shop that I want one with 8mb buffer for my new harddisk. He gave me a Western Digital Carvier SATA and told me all SATA harddisk have 8mb buffers. But I went to look around and found there are those with non 8mb buffers..

erm how can I check if my is the right one with 8mb buffers? is there really a big difference in the speed in the difference of the buffers?
I went to check on my computer(in device manager) and all the model number of the harddisk is WDC WD2000JD-00GBB0 SCSI disk device

 

[airiox]

I think it probably says on the label. And also check the model number. If there is a 2 then its prob only 2 mb. if 8 well yeah.