Re: File Systems Compared

From: "Luke Lonergan" <llonergan(at)greenplum(dot)com>
To: "Brian Hurt" <bhurt(at)janestcapital(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: File Systems Compared
Date: 2006-12-06 17:40:25
Message-ID: C19C4089.14E0D%llonergan@greenplum.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

Brian,

On 12/6/06 8:40 AM, "Brian Hurt" <bhurt(at)janestcapital(dot)com> wrote:

> But actually looking things up, I see that PCI-Express has a theoretical 8
> Gbit/sec, or about 800Mbyte/sec. It's PCI-X that's 533 MByte/sec. So there's
> still some headroom available there.

See here for the official specifications of both:
http://www.pcisig.com/specifications/pcix_20/

Note that PCI-X version 1.0 at 133MHz runs at 1GB/s. It's a parallel bus,
64 bits wide (8 bytes) and runs at 133MHz, so 8 x 133 ~= 1 gigabyte/second.

PCI Express with 16 lanes (PCIe x16) can transfer data at 4GB/s. The Arecas
use (PCIe x8, see here:
http://www.areca.com.tw/products/html/pcie-sata.htm), so they can do 2GB/s.

- Luke

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Markus Schiltknecht 2006-12-06 17:45:56 Re: File Systems Compared
Previous Message Scott Marlowe 2006-12-06 17:20:43 Re: VACUUM FULL does not works.......