Guild Wars 2

the problem arise when i change my hdd yesterday.
My HDD is at 5400RPM now.
Used to be 7400 RPM, could it be the problem?
Will RPM affect the game performance?
when i change to the old HDD and try to play guildwars2, i have no problem at all.

I have 2 GW2 account, 1 plays on a desktop(2 years old), the other on my laptop(5 years old). For the past 1 year it was fine, no problem.

Few days back i changed my desktop graphics card and internal hard disk. When i re-installed GW on the desktop and try to play, i realized i have irregular delays and lag which makes it hard to play even for PVE.

i checked the forum and realized that a lot of the people faced the same problem. (only GW2 is having delays, other games seems fine).

But the weird thing is, there is absolutely no problem with my laptop (no lag, no delays, plays perfectly fine) which is of a much lousier specs than my desktop.

my desktop does not have any antivirus software that is blocking my firewall or access for GW. I reformatted my desktop upon changing of hardware so its a fresh new computer with latest windows update.

Anyone have the same problem as me? Any advice?