Re: Reboot? Slow First Run
Re: Reboot? Slow First Run
- Subject: Re: Reboot? Slow First Run
- From: "gMail.com" <email@hidden>
- Date: Thu, 03 Dec 2009 18:55:13 +0100
- Thread-topic: Reboot? Slow First Run
Thank you Bill,
I can't really know whether I can modify that schema and unify those 10,000
files in one. I will ask the supervisor. Those files contain UT8 text and
other data like images... I know spotlight is fast enough, but here we need
to read the content of the files and process it.
As far as the speed at listing a folder content, I mean that despite to the
various improvements in the technology, I can't yet see the speed I expect
from a machine today when I open a folder. I can quite play a 3D game at
1200 fps with shaders and such (thanks to the GPU) but I have to wait
minutes or hours when I need to copy some GB between 2 disks. I know SSD is
much faster than old disk technology. However, since the old disk technology
is still largely used on Mac and this technology is still slow, I shouldn't
have designed the Finder that way. The machine looks unbalanced: you go like
a rocket when playing a game then you go like a turtle when displaying a
simple list of files in the Finder. It's just a personal opinion. Nothing so
damn important anyway.
--
Leonardo
> Da: Bill Bumgarner <email@hidden>
> Data: Thu, 03 Dec 2009 08:30:37 -0800
> A: "gMail.com" <email@hidden>
> Cc: Shawn Erickson <email@hidden>, <email@hidden>
> Oggetto: Re: Reboot? Slow First Run
>
>
> On Dec 3, 2009, at 8:10 AM, gMail.com wrote:
>
>> Thanks. I supposed that I was loading from the cache. It's a pity.
>> It was too nice to load 10,000 files x 4KB each, in only 1.2 secs.
>> Maybe one day, when I will be not longer on this planet :-)
>> Just to mention I run MacOSX 10.6.2 and I build against 10.5 (32 bit).
>
> Well.... 10,000 x 4KB files sounds like an excellent design for the benefit of
> spotlight [which needs individual files for each data item it indexes] but is
> a very poor design for reading all that data at once. Prior to the disk cache
> being warmed up, reading those 10,000 files requires a boatload of I/O of the
> worst kind in that the data is unlikely to be contiguous.
>
> If you want to speed up the initial read, cache the contents of the 10,000
> files into a single file. Even those 10,000 files laid out contiguously and
> memory mapped is going to be faster, but you can do much better by effectively
> 'compiling' the data into some form that is much more convenient to read.
>
> This is *exactly* what Address Book, Mail and other applications do. In the
> case of AB and Mail, they are using CoreData and SQLite directly respectively
> to store the data into a single file. Perhaps CoreData would fit your needs
> as well (you haven't said what the 10,000 files contain).
>
>> Anyway I would like to say a thing that I wanted to say for years.
>> Despite to the faster and faster processors and machines, the better and
>> better OSs... still today with a Core 2 Duo Intel 2.4GHz and MacOS X 10.6.2
>> at 64 bits (which is considered mainly as an improvement of the stability
>> and speed), when I open my /Applications folder, I have to wait for 3, 4 or
>> 5 seconds to see the contents of the folder. I recall that my Mac II with
>> the System Mac 1.0 (in 1988) was faster. Think over ;-)
>
> Yes, but the one thing that *hasn't* changed in all those years is that hard
> drives have *not* gotten ~150x faster [CPU speed] and zillions of times faster
> on the memory speed front.
>
> Hard drives are slow, slow, slow. Yet, the metadata being read to -- say --
> display that folder full o' applications is considerably larger. Heck; The
> recommended icon size on Mac OS X Snow Leopard -- 512x512x4 -- is *larger than
> the total resolution of the original Macintosh's screen*. Even more amusing;
> a modern icon fully decompressed will take up 1MB of RAM -- it wasn't until
> the Mac II that a Macintosh had enough memory to even load such a beast!
>
> And that is just the icons. You also have the full blown localization support
> and permissions metadata, too. The first read is several orders of magnitude
> more data, all spread around the disk, than that Mac II and from a device--
> the hard drive-- that is *not* several orders of magnitude.
>
> Now, if you want an eye opener, test your 10,000 x 4KB file read w/cold disk
> cache on a decent SSD drive...
>
> b.bum
>
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