Hard Drive Speeds Alum 12" Powerbook G4 7200rpm vs 5400rpm

[Cottonsworth]

I'm looking to upgrade the hard drive on a 12" alum Powerbook G4 I have.

I'm looking at a 100gb Seagate ST910021A 7200rpm drive vs a Western Digital Scorpio 250gb 5400rpm drive.

Both have a 8mb buffer but the 5400rpm WD has faster read seek times and average latency compared to the Seagate (12 vs 10.5) and (5.5 vs 4.2). Am I missing something here? The 5400rpm drive is faster than a 7200rpm drive? Please fill me in. Thanks.

 

[Hellhammer]

Yeah, the 5400rpm is faster as it's bigger, it's 2.5 times denser

 

[Cottonsworth]

So speed literally has to do with the physical dimensions of the platter? Are you saying that since both the 100gb and 250gb platters are the same physical size, but the 250gb one would be faster because the 250gb cover less real estate than the 100gb? Thus making the 250gb one faster? I'm trying to educate myself on the technical nature of this issue, so any further clarification would be greatly appreciated. Thanks.

 

[Hellhammer]

So speed literally has to do with the physical dimensions of the platter? Are you saying that since both the 100gb and 250gb platters are the same physical size, but the 250gb one would be faster because the 250gb cover less real estate than the 100gb? Thus making the 250gb one faster? I'm trying to educate myself on the technical nature of this issue, so any further clarification would be greatly appreciated. Thanks.

Yes. They both are made of two platters, I guess (most 2.5" are) so the 100GB is made of two 50GB and the 250GB is made of two 125GB. I'm not 100% sure but it has something to do with the density as the data is more "tightly packed"

As you see there, the 500GB 5400rpm is faster than 320GB 7200rpm drive

 

[Cottonsworth]

It's confusing because the fastest drive from that chart is a Samsung 250gb. Are manufacturer specs to be trusted? If that is the case, I'm going to go with the Western Digital 250gb 5400rpm drive.

 

[Hellhammer]

It's confusing because the fastest drive from that chart is a Samsung 250gb. Are manufacturer specs to be trusted? If that is the case, I'm going to go with the Western Digital 250gb 5400rpm drive.

Yea, it is, but look at WD's 5400rpm vs 7200rpm.

5400rpm is anyway better as it's bigger and 7200rpm could cause vibrating, heat and battery issues

 

[DoFoT9]

So speed literally has to do with the physical dimensions of the platter? Are you saying that since both the 100gb and 250gb platters are the same physical size, but the 250gb one would be faster because the 250gb cover less real estate than the 100gb? Thus making the 250gb one faster? I'm trying to educate myself on the technical nature of this issue, so any further clarification would be greatly appreciated. Thanks.

yes - speed does literally have a direct correlation to how fast the data can be written/read.

on the 100GB, in any certain area it might be able to fit in 1 1 1 1 1 1, but on the 250GB they may be able to fit in 111111111111, they both take up the same space however the 250GB can store more. the 5400RPM is indeed much much slower in reality (i think roughly 70% slower) - but the density differences clearly make ALOT more improvements to performance.

we are seeing the same thing now with VelociRapter drives vs 2TB 7200rpm drives - performance is nearly the same now!

from the benchmarks i say go with the 5400RPM - more HDD space for not roughly better performance! battery life isnt really an issues - maybe 10mins different in battery life.