hard drive speed versus size

[Anonymous]

I am shopping for a mac book pro and wanted to get opinions on the hard drive I choose. The standard is a 160 GB 5400 rpm. I noticed on my current desktop system I am using in excess of the 160 GB now, but I have not been diligent to keep things tidy. I would like to increase the size to 250 GB, but this drive is slower (4700 rpm). How much will the drive speed effect performance? Should I consider the 160 GB 7200 rpm drive?

[Anonymous]

I have found that hard drive speed has little effect on ArchiCAD performance. I once tried putting the temporary folder on a RAM drive and the performance gain was negligible. I haven't used a 4200rpm drive so I can't say for sure but I doubt you would notice the difference. AFAIK fast drives are mainly an issue for video editing.

Capacity, on the other hand, is a big eal. I upgraded my MacBook Pro from 120GB (the largest they had at the time) to 160GB only a couple of months after I bought it. I am constantly struggling to keep free space on it. I recently moved all my photos and music to an external drive as a quick fix.

I would go for the 250GB.

[Karl Ottenstein]

Hi Mike,

Data Transfer Rate (actual, not theoretical) is the key factor, not rotational speed. Unfortunately, few manufacturers/vendors post actual DTR info.

All things being equal...faster RPM 'usually' is better, but all things work together, and all things are rarely equal. 😉

As you increase the drive capacity - for a drive with the same physical dimensions and design [your case I believe] - the density of the data on the surface increases, and thus bits 'fly' by the read/write head faster simply because of density...so, a slower RPM higher capacity drive may very well have the same DTR (or better) than a higher RPM lower capacity drive [assuming the same physical read/write head / platter configuration].

The amount of on-drive memory cache, and the entire controller hieararchy (on-drive circuitry, computer bus design, OS, etc.) also impact DTR greatly. (A high speed drive that cannot read the next sector on the same revolution because controller hierarchy cannot process the data fast enough will have to skip a revolution - making the high RPM irrelevant.)

As consumers, it is really frustrating for us because we want to know DTR of a particular drive in a particular system...and the retailers, whether Apple, Dell or whoever, do not share this info. Lots of Googling and finding users who have run benchmarks seems to be the only solution that I know of today.


Cheers,
Karl

PS Later this year, drives with HUGE disk caches are supposed to start appearing. So, rather than 8 MB as a typical on-board disk cache, it will be in the GB's. These should improve performance dramatically, but I believe the first drives will only be in desktop sized units.

[Anonymous]

Thank you both so much for the advice.