Re: SSD performance

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hmm - I wonder what OS it runs ;-)

- Luke

----- Original Message -----
From: david@xxxxxxx <david@xxxxxxx>
To: Luke Lonergan
Cc: glynastill@xxxxxxxxxxx <glynastill@xxxxxxxxxxx>; pgsql-performance@xxxxxxxxxxxxxx <pgsql-performance@xxxxxxxxxxxxxx>
Sent: Fri Jan 23 04:52:27 2009
Subject: Re:  SSD performance

On Fri, 23 Jan 2009, Luke Lonergan wrote:

> Why not simply plug your server into a UPS and get 10-20x the
> performance using the same approach (with OS IO cache)?
>
> In fact, with the server it's more robust, as you don't have to transit
> several intervening physical devices to get to the RAM.
>
> If you want a file interface, declare a RAMDISK.
>
> Cheaper/faster/improved reliability.

you can also disable fsync to not wait for your disks if you trust your
system to never go down. personally I don't trust any system to not go
down.

if you have a system crash or reboot your RAMDISK will loose it's content,
this device won't.

also you are limited to how many DIMMS you can put on your motherboard
(for the dual-socket systems I am buying nowdays, I'm limited to 32G of
ram) going to a different motherboard that can support additional ram can
be quite expensive.

this isn't for everyone, but for people who need the performance, data
reliability, this looks like a very interesting option.

David Lang

> - Luke
>
> ----- Original Message -----
> From: pgsql-performance-owner@xxxxxxxxxxxxxx <pgsql-performance-owner@xxxxxxxxxxxxxx>
> To: Glyn Astill <glynastill@xxxxxxxxxxx>
> Cc: pgsql-performance@xxxxxxxxxxxxxx <pgsql-performance@xxxxxxxxxxxxxx>
> Sent: Fri Jan 23 04:39:07 2009
> Subject: Re:  SSD performance
>
> On Fri, 23 Jan 2009, Glyn Astill wrote:
>
>>> I spotted a new interesting SSD review. it's a $379
>>> 5.25" drive bay device that holds up to 8 DDR2 DIMMS
>>> (up to 8G per DIMM) and appears to the system as a SATA
>>> drive (or a pair of SATA drives that you can RAID-0 to get
>>> past the 300MB/s SATA bottleneck)
>>>
>>
>> Sounds very similar to the Gigabyte iRam drives of a few years ago
>>
>> http://en.wikipedia.org/wiki/I-RAM
>
> similar concept, but there are some significant differences
>
> the iRam was limited to 4G, used DDR ram, and used a PCI slot for power
> (which can be in
> short supply nowdays)
>
> this new drive can go to 64G, uses DDR2 ram (cheaper than DDR nowdays),
> gets powered like a normal SATA drive, can use two SATA channels (to be
> able to get past the throughput limits of a single SATA interface), and
> has a CF card slot to backup the data to if the system powers down.
>
> plus the performance appears to be significantly better (even without
> using the second SATA interface)
>
> David Lang
>
>
> --
> Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-performance
>

-- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)To make changes to your subscription:http://www.postgresql.org/mailpref/pgsql-performance

[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux