Re: SSD performance

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.

- Luke

----- Original Message -----
From: pgsql-performance-owner(at)postgresql(dot)org <pgsql-performance-owner(at)postgresql(dot)org>
To: Glyn Astill <glynastill(at)yahoo(dot)co(dot)uk>
Cc: pgsql-performance(at)postgresql(dot)org <pgsql-performance(at)postgresql(dot)org>
Sent: Fri Jan 23 04:39:07 2009
Subject: Re: [PERFORM] 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

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