Is 320Gb 5400rpm HD = 200GB 7200rpm HD in terms of speed?

I was surprised when I read this in someones post a while back. Is this true? This does not make sense to me. I was looking to upgrade my internal harddrive in my T61p with a Hitachi 200GB 7200rpm drive. Any advice and explanation would be helpful. Thanks.

 

Well... from what I understand from a few people's posts if the drive is denser (more Gb's) it can read/write more data.

 

I'm not sure of the exact spec but the idea is platter density. The more you can fit on a single platter the less the hard drive's head needs to move to find the data. Because of this, the 320GB drive, though it may be slower, the data is quicker to find because of this higher density. So the difference is almost nil when comparing these 2 drives, so if you can, get the 320GB monster to save money and get more space while keeping speed almost equivalent.

 

The idea is that the 320/5400rpm is more dense so will get to the specific information faster ore equally fast as the 200gb 7200 rpm one,whereas random searches will still be faster than the 5400 rpm one.
An HDtune of the 320/5400 rpm test here : http://forum.notebookreview.com/showpost.php?p=3259030&postcount=44

 

In general, large 5400rpm drives will have transfer rates comparable to smaller 7200rpm drives, but the seek times on the 7200rpm drives will almost always be faster. Practically, this means that large file transfers will run about the same speed on both drives, but heavy I/O operations, like an XP startup will still be a bit faster on the 7200rpm drive.

Obligatory Tom's Hardware HDD charts: http://www.tomshardware.com/charts/hard-disks/average-read-transfer-performance,675.html

 

Pretty much on the ball, thats how it works.

I personally would go for the "slower" 5400rpm drive, it has the higher value of storage and value for your dollar and I find myself out of space much easier than I find myself worried about a few seconds difference in performance.

Then factors that you can guarantee but are possible is that the 5400rpm drive could be better on battery power since it uses less power and has to do less movement to get to data, and it should produce less heat. Those points are arguable tho and vary depending on the model you choose so thats why I just put them in as "possible but not guaranteed"

 

The correct term is "Areal density" when talking about this. Or, in laymen's terms bits / square inch.

If we assume all else is identical we have a 33% rotational advantage for a 7200 RPM drive over a 5400 RPM drive (from the 5400RPM perspective).

To offset the rotational advantage, you need to increase areal density by at least 1/3 to break even. Areal density more than 1/3 larger on the 5400 RPM means that on extended transfers the 5400RPM could outperform the 7200RPM drive.

However, as others have pointed out, you do pay a penalty for seeks and random access.

Cheers,

 

There is a benchmark of my WD 320GB very close in performance to the 7200 200gb hard drive, it is about 2ms slower or so in access times, but I don't notice any slow down at all, and i've used 7200 drives in laptops for a while.