Which drive is faster? A sata II 7200rpm or a sata III 5900rpm?

[TheDarkKnight]

Just as examples:
http://www.newegg.com/Product/Produc..._-22148725-L0C

versus

http://www.newegg.com/Product/Produc...82E16822152181

It seems that 5900rpm Sata III drives can be as fast or faster than Sata II 7200rpm drives. Which is the best drive to purchase for speed?

 

[Turbonium]

I'd go with a 7,200rpm drive, but I haven't really researched it at all.

 

[lehtv]

Even 7200RPM hard drives don't saturate the SATA II bandwidth, so the 7200RPM 3gb/s drive is going to be faster than a 5900RPM 6gb/s drive. There are also other factors to speed than RPM and bandwidth... in particular, platter size. New drives with large platters have highly concentrated sectors which improves performance because the spindle has to move less between sectors (at least that's how I think it works... correct me if I'm wrong.)

Since you're comparing a 90 dollar 1.5TB drive to an 80 dollar 500GB drive, I'd highly recommend the bigger drive even if it was a bit slower. But in my opiinion these are all better deals than the ones you linked:

Samsung/Seagate 1TB 7200RPM HD103SJ $80 after promo - dual 500GB platters
Seagate 1TB 7200RPM ST1000DM003 $100 - single 1TB platter, it's very fast
WD Caviar Black 1TB 7200RPM WD1002FAEX $120 - dual 500GB platters, but awesome FIVE year warranty

 

[npaladin-2000]

If it's not an SSD I generally only buy Western Digital's Black series. Though Seagate's Momentus XT is a nice drive also.

 

[TheDarkKnight]

Why do hard drive manufacturers even sell a SATA-III hard disk drive with an RPM of 5900 if it can never reach it's maximum potential speed? More marketing deception?

You yourself stated that its possible for a 5900rpm drive to be faster than a 7200rpm drive "if" the platters are bigger.

But it seems the form factor is still the same so I am not sure how that could be possible.

I tend to go with the best bang for the buck. Newegg is selling the 1.5TB Seagate drive for $89.99 on the memorial day sale. Its the slower rpms but that is a great deal for somebody who just wants to store data or watch movies. The extra speed wouldn't matter.

 

[Turbonium]

Why do hard drive manufacturers even sell a SATA-III hard disk drive with an RPM of 5900 if it can never reach it's maximum potential speed? More marketing deception?

It's probably just a product- and supply-line sort of thing. They got a bunch of SATA-3 controllers/interfaces in a product-line, for example, and that product-line has drives at different rpm speeds. They're likely not going to determine if a given controller/interface is "too fast" for a given drive's internals, as that would take time, effort, and ultimately, money.

That, and marketing a drive as being SATA-3 helps it to sell.

Someone correct me if I'm wrong on this.

 

[Elixer]

Yeah, one big marketing ploy to use SATA III instead of SATA II. (Heck, even SATA I)

For the OP, it depends on the drive, some 5900 RPM drives are faster than some 7200 drives. It just depends on platter density.