to run AH is it better a 2,5 or 3,5 inches hard disk ?

[Rob52240]

Physical size doesn't matter.  The speed that the platter rotates does matter.

[MrRiplEy[H]]

Physical size doesn't matter.  The speed that the platter rotates does matter.

No, both the capacity and rotational speed matters due to the platter density. Physical dimensions of the drive do not mean anything.

[Torquila]

Don't be delusional, size allows more platters.

[MrRiplEy[H]]

Don't be delusional, size allows more platters.

There are already 1Tb 2,5" drives so that's hardly a problem. Regardless of the fact I wouldn't recommend to anyone to get a regular HDD in 2,5" form factor, they're best in 3,5" form. Just the mounting brackets are good reason to get the 3,5" model. SSD:s are however different, the 3,5" size drives are rare and generally overpriced compared to the regular 2,5" models.

[Torquila]

I have yet to see a retail 3.5 SSD as well, I think they are only reserved for enterprise applications.

[Denniss]

Physical size doesn't matter.  The speed that the platter rotates does matter.

Using your example: a 2-liter 4-cylinder engine generates more power than an 4-liter 8-cylinder engine just because it runs at up to 6000rpm vs the 4000 of the 8-cylinder.
Do you see the problem with your argument?

[lulu]

TY

[lulu]

TY


 


P.S.

Sorry, a mistake have made me to duplicate the post.

[Bizman]

No, both the capacity and rotational speed matters due to the platter density.

I agree, that is totally logical. A faster spinning speed brings a required disk sector faster under the read/write head, whereas more capacity means more tracks and sectors to bypass while searching for the required one. Wikipedia has a nice short article about hdd performance characteristics

]Physical dimensions of the drive do not mean anything.

I disagree with that: Logically, if all other values are identical, the actuator arm needs to make smaller movements on the smaller platter. A smaller distance takes less time to travel if the speed is the same.

[Skuzzy]

Hard drive performance is all about areal density and rotational latency, regardless of the form factor.

Take a 2.5" 100GB drive versus a 3.5" 200GB drive.  The areal density is higher with the 3.5" drive and if both have the same rotational latency, then the 3.5" drive is faster.

Take a 2.5" 100GB drive rotating ay 15,000 RPM, versus a 3.5" 200GB drive rotating at 5400RPM, the and the 2.5" drive will be faster due to a significantly lower rotational latency.

[MrRiplEy[H]]

I disagree with that: Logically, if all other values are identical, the actuator arm needs to make smaller movements on the smaller platter. A smaller distance takes less time to travel if the speed is the same.

Yet it has nothing to do with the drive form factor. Take for example WD Velociraptor which is 3,5" form factor but has 2,5" platters.

[Bizman]

Yet it has nothing to do with the drive form factor. Take for example WD Velociraptor which is 3,5" form factor but has 2,5" platters.

Sorry, my bad. I mismatched form factor and platter diameter.

[Spikes]

Except SSD disks where 2,5" is the norm. The 3,5" drives are an oddity in that field - so if it's going to be SSD go for 2,5" - more selection and lower prices in that category.

I was under the assumption he was not asking about SSDs since he said hard disk (drive).

[MrRiplEy[H]]

I was under the assumption he was not asking about SSDs since he said hard disk (drive).

There is reasonable doubt considering he was asking about SSDs in the parallel thread.