Which is faster? The hare on nyquil or the tortise on crank?

January 5, 2009 2:26 PM

I have a 5400rpm SATA 3.0Gb/s & 7200rpm SATA 1.5Gb/s drive. Wondering which one to put in a laptop (which one would give better performance, if noticeable). Thanks!

The laptop will be used for 1) listening to music 2) running code and processing thousands of data files 3) the occasional photo edit.

posted by Upal to computers & internet (13 answers total)

Gah! Forgive my spelling error.
posted by Upal at 2:27 PM on January 5, 2009

What's the model and made, etc.?
posted by holloway at 2:37 PM on January 5, 2009

Unless you're constantly moving large chunks of continuous data, my inclination would be towards the 7200rpm drive because it'll probably seek quicker. Find out the seek times.
posted by hobbes at 2:41 PM on January 5, 2009

Both are Hitachi, the SATA 3.0 is 5K160 & the other is 7K200.
The 7200rpm has a 2ms quicker seek time and a 1.3ms lower latency average.
posted by Upal at 3:01 PM on January 5, 2009

The 7200 RPM drive. Better benchmark performance (lower rotational latency). SATA speed is either 150MB/sec or 300MB/sec. You may occasionally be hitting that 150MB/sec transfer speed ceiling on SATA I, but you won't be over that limit consistently for any period of time.
posted by defcom1 at 3:05 PM on January 5, 2009

7200rpm drives will use more power (in general) than a 5400rpm drive. If battery life matters to you.
posted by blue_beetle at 3:06 PM on January 5, 2009

Are the drive capacities the same? If the 7200rpm drive is higher capacity, data density will be higher, resulting in higher transfer rates, independent of the SATA speed.

Essentially, you're not saturating the SATA (I) bus, so the higher speed SATA interface is just gravy when you're moving to/from the drive cache, which is far outweighed by the decrease in rotational latency.

Of course, the 7200rpm drive may very well have higher power consumption.
posted by defcom1 at 3:09 PM on January 5, 2009

Battery life will actually stay largely the same. It takes more power to spin at 7200rpm, but you'll be done spinning the platter that much sooner. There's a very slight impact on battery life, but only very very slight. If you'll see any serious boost in performance from the faster drive, I'd suggest going for it.
posted by Tomorrowful at 3:35 PM on January 5, 2009

Figure out which has the larger cache, that would be my deciding factor. If that's the same, I'd use the 7200 rpm drive. You are unlikely to bump into the SATA limit.
posted by chairface at 3:56 PM on January 5, 2009

Not all computers are capable of operating at the 3.0 Gigabit speed, in which case 3.0 drives are actually operated at the 1.5 Gigabit speed. So I would figure out what your computer can handle. If you can only run at 1.5, I guess that would make the decision pretty easy.

Mind you, I'm not totally sure about this, and it could be heresy, so you should independently verify. I'm trying to buy a new hard drive myself and that's something I discovered about my MacBook.
posted by Sfving at 4:18 PM on January 5, 2009

I changed from the original 4800 to a more spacious 5400 in my Macbook, and it has failed twice in short time. The fans have been spinning more than previously, so even though my advice is anecdotal I'd check for heat issues with your laptop. Higher rpm means higher temperature, and that could be an issue. (YMMV)

Other than that, I notice the speed increase because of the higher rpm (and cache size) so would recommend the faster drive.
posted by monocultured at 5:09 PM on January 5, 2009

There are no rules. Read the specifications for the specific models of each drive, and compare apples to apples. The rpm number is only the way the drive makes its performance, not performance in and of itself. Quite like the MHZ of a processor- an efficient, slow processor can be faster than a fast, inefficient one.

Things to look for- latency, sustained transfer rates, how much power it uses. There is plenty of overlap in these numbers between 5400 and 7200.

(In a laptop that's being used, the hard drive is probably spinning. It doesn't spin up and down like a floppy disk or a cdrom. They do spin down, but only when the operating system tells it to in the power options.)
posted by gjc at 7:26 PM on January 5, 2009

Based on the small amount of info, I'd say the faster RPM one is better, as you said you'd be using many code files, which sounds to me like that would call for a lot of seeking.

A key aspect I don't see is the size of the drive cache. This is a bit of memory on the drive that stores data the drive will write (IIRC). It's great if you make lots of small file changes, as the drive usually can't write fast enough to keep up with most programs. The buffer, if large enough, can hold the data so that the program can still run without having to wait for the drive to finish. The operating system itself makes lots of small writes like this, so this is desirable for pretty much anyone.

I googled those drives. The 5400 one only seems to come with SATA 1.5, while the 7200 is the one with SATA 3.0. Are those model numbers correct? What about capacity?

Also, definitely check if your laptop has SATA II capacity. It's not really a big deal, because most drives can only reach the max transfer rate for a short amount of time before they run out of space in the drive cache and need to wait for the slower mechanical parts to catch up on the fly.

The 7200 drive has a larger cache, which is a pretty compelling argument for it.

Defcom1 is right that drive density can make rotational speed irrelevant. Dansdata.com just reviewed a 5400 1TB drive that went pretty fast for actual transfer, and it had similar performance to the 7200 version of the same drive.

However, from what I see, the 7200 drive is in a larger range of capacities than the 5400 drive. It's starting to look like it's the completely better option.

However, specifications tend to not add up right in the real world. Google reviews for them, hopefully from enthusisast sites. Random read and write speeds are probably best for your code, and fast sustained speeds are better for playing music and movie files. Music actually isn't that big a deal, unless you use a loseless format, so I'd worry about that less. Movies are huge, though, so keep the transfer in mind for them.
posted by mccarty.tim at 8:01 PM on January 5, 2009