HD tune problem with new Seagate harddrive need help ASAP!

I need someone to explain my HD tune results on my new hard drive its a Seagate Momentus Thin ST500LT012 500GB 5400 RPM 16MB Cache SATA II 3.0Gb/s 2.5" on a ASUS eee 1000h netbook(yes i know its old but i really like this netbook) with 2GB ram.
I already returned one harddrive because i thought it was damaged and got a new one its exactly the same harddrive and I still got the same result again im running HD tune on a new installed Win XP home 32 bit and all drivers are updated incl BIOS and no programs in the background I have checked task manager and there is no activity when im running the test and I let the let computer idle 15 min before i start but still got this big drop in the beginning and my transfer rate is really low and my burst rate is also really low. Ive tried in Safe mode and tried HD tune on a usb stick and a external harddrive all the same result. Checked the harddrive and there is no damaged blocks on it. Anyone got any idea why its acting like this? Is the harddrive to good for this netbook or am I missing something some adjustment? I tried HD Tach too but its not the same result.

First picture is the first harddrive i returned second picture is the one i got now.

 

they look fine to me.
5400rpm drives are the slowest you can get now.
then you have 7200rpm followed by hybrid or whatever they are called and then finally SSD's

these are my 2 drives. one a western digital 7200rpm which is about 3 years old and running slow. the laptop is only used for emails now so not really cleaned up in a couple of years.
and my 2 year old SSD.

 

That is perfectly normal, all HDDs running HDtune from Windows will show that. The only time you won't get variance is when you run HDtune on the HDD externally (i.e. from another Windows installation on another HDD).
The reason for the dip is usually because of Windows, it basically means, the OS interrupted the HDD while it was doing the sequential read (i.e. forcing it to reposition the head on to a different track briefly). If you are really paranoid, get another Windows machine and run HDtune from that on this HDD.

 

Agreed, it's normal. If you ever want to know if there is something wrong with your drive, you can run the error check on HD Tune, in which damaged sectors will show up red.

 

Thank you guys for the information. Still not satisfied with my new harddrive the overall performance is really slow shutdown xp takes like 5 min and just to empty the recycle bin with just 2-3 mb takes minutes my old harddrive was a Samsung spinpoint 320gb 5.300 8mb was much faster and never slow like this one. Maybe some setting? I did change from AVG free antivirus to AVAST on this one could be that. :-/

 

I'm sure the problem isn't with the drive itself but the Windows / software installation.

You've mentioned a change in the AV software and that could well be a reason. Possibly not the software itself but a default configuration scanning everything that gets accessed. With a netbook CPU such scanning takes a lot more time than on a machine with a more powerful CPU. So I would suggest you look through the configuration options and slim down to scanning files that come into the computer (from internet, flash drive, etc) and not when they are accessed on the computer.

John