Hard Drive Questions (Raid 0 & RPM)

1) Raid-0 is stripping which separates the data on both drives. If one breaks, you lose everything. But stripping is way faster than having no raid at all

No raid compared to raid-0 is slower data transfers and compared to raid-1 is less secure.

NB: Raid-1 is mirroring, in that case the second drive is an identical copy of the first. If one of the drives break the other will still have the data in it.

2) High RPM drives are faster at transfering data but... the faster you go, the hotter it gets.

There are almost no cases where RAID0 is "way faster". In almost all desktop performance cases, RAID0 nets you a few percent at most. Apps that require long contiguous reads from disk benefit from RAID0, but there are very few desktop applications that perform a lot of the reads where RAID0 excels. For disk accesses that are scattered around the platters, RAID0 does nothing for you, and in some select cases, can even hurt performance. And RAID0 does absolutely nothing for access latency. A higher RPM disk will help reduce access latency, though. And 7200 rpm drives don't produce that much more heat than 5400s.

In laptop drives it is not entirely nessary unless you have some specific purpose or benefit from RAID1 (backup.) However, you would definitely benefit from the higher 7200RPM drive with lower read/seek times, faster map loading for gamers, and etc. The extra heat with along with the RPMs is negligible in modern drives vs 5400RPMs.

non-raid 5400RPM for the win

as far as i am informed, it is practically impossible to tell the difference on everyday computing (music/dvd/word/internet) between 7200RPM and 5400.

with 5400 u can go as big as 160GB...but with 7200 only 100GB

The differences are noticeable for things that are disk intensive. Things like loading applications and starting Windows will improve measurably. Loading Photoshop and Illustrator on a 5400 rpm drive is painful (I know, I do it all the time). Once they're open, though, the disk doesn't make a difference to how they perform, though. Likewise, opening large files will also benefit. AirForceElite pointed out that 5400s can be had in larger capacities. Higher data densities improve performance (the data is packed closer together, so the disk head travels over and reads more bits per uinit time). So if sustained reads are important to you (like you frequently open a lot of large files), then a higher density 5400 can give you better performance (and more room to store stuff too). You aren't always disk-limited, though. For example, if you're looking to improve gaming performance, a faster disk isn't going to do a damn thing (other than for stuff like loading levels as Charles noted), and you may want to choose on the basis of cost/megabyte or some other determinant.

Native command queing isn't that big a deal. Pretty much all SATA disk support it now, but it rarely helps much for desktop apps. IDE drives don't support it, but it's really not a big deal. Disk write performance is just about a complete non-issue for desktop systems. Read performance matters more, but NCQ doesn't help all that much with the big killer of disk performance for desktop stuff--latency. NCQ can re-order reads and writes to minimize head travel, but re-ordering a read from ABC to BCA doesn't help if the application really needs A first.

Woland hit the nail on the head concerning the difference between 5200rpm and 7200rpm drives ...data density plays a large role and can cause a lower rpm drive to actually be faster than a higher rpm drive.

The one thing he touched on is in the situation where you might have too little memory for the applications you are running/multitasking causing significant and often disk swapping. Someone running 2GB may not notice the difference as much as someone with only 1GB.

In a two-disk environment, I'm not sure I'd go with 2 7200rpm drives ...probably get slightly better bang for your buck to go with a lower volume/higher rpm drive for the OS (and swap file) and a higher volume/lower rpm second drive for storage. At least, that would be my strategy ...

RAID 0 is more of a gaming thing really. It's nice when playing Battlefield 2142 on the Straferight servers because I'm one of the first people to load the map, so I get my kits configured and I get first dibs on vehicles. My RAID 0 array with two 16MB cache 7200RPM drives is a bit faster than a single 10,000 RPM Raptor. It has no other real advantage otherwise.

Woland is right though, Areal density trumps spindle speed.

Here's an article that may be of interest regarding the Raptor drives vs 7200 RPM drives : http://www.tomshardware.com/2007/03/...tor/index.html


Back to the OP's topic: I've had notebooks with a) one 100GB 7200 RPM Drive, 2) one 160GB 5400 RPM drive, and 3) two 160GB 5400 RPM drives in Raid 0.

To be honest, I don't really see a noticeable difference in performance between them. I'm sure this is because I'm not doing particularly disk-intensive work on my notebooks. Right now, I think the 160GB 5400 RPM drives are the sweet spot for people who use their notebooks for gaming and normal productivity apps, because you get lots of storage and good speed with the disk density.