640gb 5400rpm>320gb 7200rpm?

[m3ta1head]

So I got my new 2.5" storage drive in-the WD Blue 640gb. I'm currently using it in an ultrabay HDD caddy in my T400 (see sig).

Imagine my surprise when I fired up HDTune only to find that my tried and trusted Scorpio Black 320gb was outpaced by this new drive!

The 5400rpm drive has a slightly slower access time as expected, but WTF why is it reading faster than my 7200rpm drive? The 640gb has 8m cache, vs 16m for the 320gb. Are these values in line? I know the 640gb is a dual 320gb platter drive-is the higher density of the platter contributing to faster speeds?

 

[0ptional]

It's the crazy density, this has been posted quite a few times, I did the same upgrade in my MBP, great upgrade.

 

[m3ta1head]

It's the crazy density, this has been posted quite a few times, I did the same upgrade in my MBP, great upgrade.

I think I'm going to retire the WD 320gb and replace it with a X-18m. X-18m+640gb storage drive in a 14.1" notebook...awesome? Hell yes.

 

[0ptional]

I'd probably do the same in my laptop if I didn't wanna give up my optical drive and if OS X had trim support, which seems like an odd omission considering they ship laptops with SSD's...