how does drive speed affect performance

Discussion in 'Buying Tips, Advice and Discussion (archive)' started by biohazard6969, Jun 24, 2005.

  1. macrumors 6502a


    Feb 23, 2005
    toronto canada
    ok, i'm thinkin about upgrading my PB hard drive soon and i was just wondering, you see all this stuff about a 60 GB 5200rpm then there would be a 100 GB 4200 rpm for a lot less. i'm just wondering, how much will the speed of the drive affect the overall performance, and what significance is there to the drive speed anyways?
  2. Moderator emeritus


    Jul 24, 2002
    Hard drive speed effects performance in lots of obvious ways and in many more subtle ways as well. Every time you start up your Mac it has to load the OS from the harddrive. Every application of file you open is ready from the disk. But worse than that a lot of background stuff uses the disk. Say you are browsing the web. Everything you see on screen has probably been cached for faster access next time you hit the page. A slow disk not only slows down cache reads but cache writes as well! This is just an example. Your disk is being used for so many operations it makes sense to have a fast one if possible.
  3. macrumors 604


    Jan 20, 2005
    A 60GB 7200RPM hard drive would be even better. A faster HD allows programs to launch more quickly, faster disk operations, and for systems with low RAM, significantly faster performance with disk caching.

    Also depends on what you do. If you surf and email, a slow disk is perfectly acceptable. But if you work with large photoshop images, edit videos or burn discs, a faster HD is very noticeable on performance.

    I'm waiting for 7200rpm 2.5" hard drives to drop in price before I upgrade the HD in my 12" PowerBook.
  4. macrumors member

    May 16, 2005
    jsut to let you know, i read an article about hard disk speeds on identical drives,

    the diffrence in battery life, and heat is almost undetectable something like a 2% run time diffrence between 4K and 7K. the diffrence in performance between a 4K and a 5K is roughly 13% and 5K to 7K is roughly 17%

    so basicly get the fastest drive witht he amount of space you need, that you can afford.

    drive speed DRASTICLY affects start up time.
  5. macrumors 6502a


    Apr 16, 2004
    on the sofa
  6. macrumors 68000


    Jan 22, 2003
    In your head.
    Don't expect to be to portable with a 7200 drive. The draw in power is signifantly more than a 5400 or slower. I noticed a marked diffrence in bootup with my new 5400 100Gb drive. I also picked up a drive with a 16Mb buffer, most have an 8Mb, and this seems to make a diffrence.

    I only changed the drive out because I had to. My machine is better in every way. The stock 40Gb drew more power, produced more accustic noise, ran hotter, had a smaller buffer, and of course stored less. Shop around.

    The thread about my Hd replacement is here.

    A link to where I purchaced the HD is here.

    I purched the drive from Mac Sales/Other World Computing and they were competative, and for $7 dollars I had I recieved the drive in 17 hours. (Placed the order at 4pm and recieved it at 10am the next day.) Their sales staff suggested the drive I purchaced, which was less expensive and had a larger buffer than the drive I was looking at.
  7. macrumors 6502


    Apr 30, 2005
    It depends on the kind of load your system is put through. In all modern operating systems (including Mac OS X), the hard disk is used as if it were a part of your main memory (RAM). So whenever an application requests for memory (RAM) and the OS finds that there's not enough RAM available, then it would "swap" some unused data/programs from RAM to the hard disk and allocate that RAM to the application. When the "unused" part is required back in the RAM, something else could be swapped out and the previously swapped out data could be swapped in. This is completely transparent to the application (except for the delays the user might notice when the swapping happens). So if you use heavyduty applications that might potentially use a lot of RAM, in addition to getting the maximum RAM you can afford, you'd be better off getting the fastest hard disk possible so that any swapping that happens is faster.

    Although RAM by itself is still slow and is a speed bottleneck for current processors, the hard disk is several thousand times worse! So if performance with heavy duty application really matters, you need a bigger and faster hard disk.

    Note that the above is a very simple explanation of swapping/paging. The actual implementation of operating systems are usually designed to always use swap (regardless of free RAM).
  8. macrumors 68030


    May 11, 2004
    fig tree
    i read somewhere that a 100gb 5400rpm drive is about as fast in daily tasks (not benchmarks) as a 60gig 7200rpm drive due to data density being higher on the 100 so it has to move less to read some data but cant remember :confused: i have a 7200rpm drive in my notebook it doesnt drain much battery (i get 4.5-5hrs) but i have nothing to compare it against. you might want to take a look at wattage ratings for various drives. i believe a hitachi e7k60 uses something like 3 watts but i could be wrong.
    sorry for the lack of facts but meh
  9. macrumors member

    May 16, 2005
    wrong, according to MANY MANY MANY MANY diffrent sources that have done independent tests on notebook drives the toll taken in battery life equates to somewhere between3-5 minutes, hardly makes any diffrence, especially when you consider that you can do things much faster so ACTUALLY there is a gain, in a sense because productivity increases while battery life stays almost the same.

    one such test
  10. EGT
    macrumors 68000


    Sep 4, 2003
    I've been thinking about installing a new hard drive as well. I had my eye on a 100gb Toshiba drive with 16mb buffer but i'm intrigued by this 2.5" 160GB seagate drive! Anyone know when it'll be available?
  11. macrumors 68020

    Feb 12, 2005
    Not really. Look at the manufacturer's specs on various drives and you'll see 7200 rpm draw nearly the same amount of current as 4200 and 5400 rpm drives. In fact, there is one 7200 rpm drive (I don't recall the brand right now) that actually draws a tiny bit less current than a Toshiba 5400 rpm drive. Hard drive technology has come a long way since the first Seagate Barracuda 7200 rpm desktop drives that ran REALLY hot and sounded like a turbofan.

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