[geeks] Flash drive questions

Lionel Peterson lionel4287 at verizon.net
Sun Aug 6 19:57:18 CDT 2006


>From: Phil Stracchino <phil.stracchino at speakeasy.net>
>Date: 2006/08/06 Sun PM 04:09:36 CDT
>To: The Geeks List <geeks at sunhelp.org>
>Subject: Re: [geeks] Flash drive questions

>Mike Meredith wrote:
>> On Sun, 6 Aug 2006 15:33:27 -0400, James Fogg wrote:
>>> devices can only be written/erased a certain number of times before
>>> they die.
>> 
>> Certainly, but the problem is over-rated. Firstly, flash devices spread
>> the write load across the whole device when they can. Secondly modern
>> flash devices are reliable up to around a million write cycles.
>
>Well, yeah.  But system memory gets written how often?  I'd 100% believe
>any given location in system memory on a hard-working machine might get
>written a million times in a year.

But if you only stored executables that are written once, and not altered, you could go a long time before you hit a million writes.

The idea is not to use the flash drive for scratch pad/temporary files, but nearly static files that take up a lot of space and are used infrequently (relatively speaking - like DLL files)...

Also, once written they can be read infinitely without damage (as I understand it)...

>>> Fixed disks aren't as fast as system memory, true, but are faster than
>>> flash memory. As for read speed, USB devices cannot read as fast as a
>>> fixed disk due to the faster interface for disks.
>> 
>> Firstly flash memory isn't *that* slow ... I've seen a comparison
>> benchmark of a flash-based laptop hd replacement that at worst is half
>> the speed of fixed disks. It's also getting quicker faster than fixed
>> disks, and that's just the consumer end of the market. 
>
>So, at worst, hitting the flash-based portion of system RAM incurs only
>about twice the performance hit of paging to disk.
>
>Ummm..........  Dunno about you, but I'd consider that a problem.
>Especially if the flash was the majority of my RAM.

Power conservation is a factor, but half as fast is slower...



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