Hard Disk Drives' Speed and Density

[Umang Goel]

What are differences between 5400 rpm and 7200 rpm hard disk drives and how does density affect these ?

 

For what purpose is 7200 rpm better and for what purpose is 5400 rpm better ?

 

I read at many places that 7200 rpm is better for loading applications, etc but 5400 rpm is better for file transfers. Is that because 5400 rpm HDDs have better densities than 7200 rpm ones ? 

 

Do all 5400 rpm HDDs have greater densities than 7200 rpm ?

 

I even read that a HDD with great densities can be faster than SSDs with file transfers. Is it so ?

 

But WD doesn't mention the densities of its HDDs, so how can we differentiate their performances just on the basis of rpm ?

 

And finally, what are 2.5" and 3.5" form factors ? Do they also affects the performance of an HDD ?

[lh99]

So the king of the hill´s are 7200rpm 3.5"

closley followed by 7200rpm 2.5" (due to waver size,and acces times)

 

5400rpm´s are  always slower bc  of rotation speed

there it is the sam first 3.5" and then 2.5"

 

ssds are faster at everything bc of acces times ande pure seq write, u can´t match this even not with 10000rpm ones (they are for servers, but getting replaced by ssd´s)

[Moonzy]

9 minutes ago, Umang Goel said:

What are differences between 5400 rpm and 7200 rpm hard disk drives and how does density affect these ?

RPM difference doesnt cause much difference in speed,

a speed of the drive relies on many more factors, like how fragmented are the data you're trying to access, and how dense are the data packed together etc etc

higher data density + lower fragmentation + higher rpm = theoretically faster speed

but in real life both drives will almost be similar performing, while the 7200rpm might be slightly faster

9 minutes ago, Umang Goel said:

For what purpose is 7200 rpm better and for what purpose is 5400 rpm better ?

depends on the use case, but i'd say the 7200rpm can access data slightly faster

but if you're into speedy storage then you might wanna get an SSD

9 minutes ago, Umang Goel said:

I read at many places that 7200 rpm is better for loading applications, etc but 5400 rpm is better for file transfers. Is that because 5400 rpm HDDs have better densities than 7200 rpm ones ? 

no, it depends on the model and other factors like i stated above

9 minutes ago, Umang Goel said:

Do all 5400 rpm HDDs have greater densities than 7200 rpm ?

nope

9 minutes ago, Umang Goel said:

I even read that a HDD with great densities can be faster than SSDs with file transfers. Is it so ?

no, SSD are way faster at read/writes because they dont have to wait for the data to arrive at the read/write head, they just access all data simultanously

9 minutes ago, Umang Goel said:

But WD doesn't mention the densities of its HDDs, so how can we differentiate their performances just on the basis of rpm ?

benchmarks, but it doesnt matter tbh, HDD are just for mass storage nowadays,

for speedy tasks, SSD are the way to go

9 minutes ago, Umang Goel said:

And finally, what are 2.5" and 3.5" form factors ? Do they also affects the performance of an HDD ?

2.5inch hard disk are smaller hard disks, typically used in portable devices such as laptop

3.5inch HDD are those thick and big hard disk typically used in desktops

 

as for speed, the 3.5inch can be faster then the 2.5inch, but this also have to depend on few factors

but in general, they are faster

[Senzelian]

A faster spnning drive will be able to read and write data quicker. The density just determines the capacity. 

Slower drives are usually more quiet, power efficient and more reliable, which makes them better for servers, where speed doesn't really matter.

A HDD could theoratically be faster than a SSD, but you would have to stack a ton of platters over each other to get to such high speeds. SSDs are generally much faster in every aspect.

We can differentiate their performances by simply doing benchmarks and tests. The same thing we do with every other piece of hardware. You'll find performance tests on pretty much any HDD.

Yes, the form factor impacts the performance of a HDD, because a smaller form factor means less platters, and therefor less performance.
But these days they're still pretty quick.

[vanished]

8 minutes ago, Umang Goel said:

I read at many places that 7200 rpm is better for loading applications, etc but 5400 rpm is better for file transfers. Is that because 5400 rpm HDDs have better densities than 7200 rpm ones ? 

where did you hear that?  It's not like different speeds are specialized for different types of use.

 

Basically, a faster (7200 RPM) drive will be faster than a 5400 RPM drive, if everything else is the same.  Generally though you will find that larger drives (like 2 or 3 TB+) are running slower (5900 RPM) because they can get the same bandwidth as a lower capacity drive (1 TB for example) running at a higher speed, since the higher speed and lower density "cancel out" so to speak, since they will result in similar amounts of info passing under the head in any given amount of time.

[Umang Goel]

10 minutes ago, Senzelian said:

A faster spnning drive will be able to read and write data quicker. The density just determines the capacity. 

Slower drives are usually more quiet, power efficient and more reliable, which makes them better for servers, where speed doesn't really matter.

A HDD could theoratically be faster than a SSD, but you would have to stack a ton of platters over each other to get to such high speeds. SSDs are generally much faster in every aspect.

We can differentiate their performances by simply doing benchmarks and tests. The same thing we do with every other piece of hardware. You'll find performance tests on pretty much any HDD.

Yes, the form factor impacts the performance of a HDD, because a smaller form factor means less platters, and therefor less performance.
But these days they're still pretty quick.

Is density simply what we call capacity? 2 TB, 4TB ?

[vanished]

Just now, Umang Goel said:

Is density simply what we call capacity? 2 TB, 4TB ?

no, density is the capacity divided by the total surface area of the platters.  Like, GB per square inch.

[Umang Goel]

Thank you everyone

[Godlygamer23]

In addition to the above, firmware also makes a big difference, and performance can also be improved by using technology such as Native Command Queuing.