SSD drives

[Dan Shimshoni]

Thanks!

Which File System  do you have on your SSD, if I may ask ?

DS

On Sun, Dec 30, 2012 at 8:46 AM, shimi <linux-il at shimi.net> wrote:
>
>
>
> On Sun, Dec 30, 2012 at 6:26 AM, Dan Shimshoni <danshimsh at gmail.com> wrote:
>>
>> Hi,
>>
>> 2 Questions about SSD drives:
>>
>> First, I would appreciate of someone who has SSD disk will
>> run
>> hdparm -t /dev/sda
>> and post the results here. (In the spirit of the recent thread about
>> HW for linux).
>>
>> I have
>> /dev/sda:
>>  Timing buffered disk reads: 586 MB in  3.01 seconds = 194.68 MB/sec
>> And it interests me to compare results
>>
>>
>
> An almost two years old Intel X25-E :
>
> # hdparm -t /dev/sda
>
> /dev/sda:
>  Timing buffered disk reads: 714 MB in  3.01 seconds = 237.40 MB/sec
>
> # uname -a
> Linux matrix 3.6.2-gentoo #1 SMP PREEMPT Sun Oct 21 22:49:01 IST 2012 x86_64
> AMD Phenom(tm) II X4 955 Processor AuthenticAMD GNU/Linux
>
>
>>
>> Does a result of, let's say, 400  MB/sec, which is double speed comparing
>> the
>> above result, will boost a task of building a linux kernel (on a dual
>> core machine)
>> in about 1.5 or 2?
>>
>
> I really don't think so. SSDs (IMHO) makes computer much faster due to the
> VERY low seek time - the time it takes you to get a block. Compare 10-20ms
> with ~0.1ms. A regular hard drive simply wastes a lost of time seeking the
> data, instead of... reading it :) When you work with a lot of files, getting
> to the file fast makes a tremendous difference. This is similar to the
> reason why browsing websites which are close to you network-wise is much
> faster - even though the bandwidth you have is the same - the client/server
> latency due to the network affects the time it takes you to negotiate
> (compare to 'seek') with the server the content you want. The more objects
> you want, the higher the latency, the slower the site will load. This is why
> using CDNs and reducing the number of HTTP requests (e.g. by using CSS
> Sprites) - help a lot in speeding websites.
>
>>
>> Second question:
>> I must admit that I am a newbie with SSD, so this question might seem
>> obvoious to others:
>> I saw that inner SSD disks, which are sold in stores like KSP/Ivory,
>> are in laptop form factor (2.5'').
>>
>> Is there some reason that there are no inner 3.5'' disks for Desktops
>> (there
>>         are extenal SSD which can be , so I believe, used with desktops) ?
>
>
> Hard Drives have a reason to be large - they have a platter that occupies
> space. If you reduce the platter size, you need to enlarge the density, or
> add more platters - which adds thickness, noise, heat, and lowers your MTBF.
> Electronics nowdays are small and doesn't need all that... There's no point
> in making a large chassis just for the purpose of a large chassis...
>
>
>>
>> Is there something which prevent us from connecting 2.5'' inner SSD to
>> a desktop (I mean STAT2- based or SATA3-based)  ?
>>
>
> Not really. The SATA is the same. Your only issue is fixating the drive to
> your PC chassis. Some computer cases have a special place for 2.5" drives
> for SSD (like my Antec 1200). Alternatively there are 3.5"->2.5" adapters.
> But learn from someone who made a mistake (me ;)) - check before you buy
> that they're compatible with the screws location of the SSD.
>
> HTH,
>
> -- Shimi
>