Re: PostgreSQL and Ultrasparc T1

Jignesh,

On 12/19/05 6:27 AM, "Jignesh K. Shah" <J(dot)K(dot)Shah(at)Sun(dot)COM> wrote:

> Sun Fire T2000 has 3 PCI-E and 1PCI-X slot free when shipped. Using
> dual fiber channel 2G adapters you can get about 200MB x 8 = 1600MB/sec
> IO bandwidth. Plus when 4G HBAs are supported that will double up. Now I
> think generally that's good enough for 1TB raw data or 2-3 TB Database
> size. Of course typically the database size in PostgreSQL space will be
> in the 100-500GB range so a Sun Fire T2000 can be a good fit with enough
> area to grow at a very reasonable price.

The free PCI slots don't indicate the I/O speed of the machine, otherwise
I'll just go back 4 years and use a Xeon machine.

Can you educate us a bit on the T-2000, like where can we find a technical
publication that can answer the following:

Are all of the PCI-E and PCI-X independent, mastering channels? Are they
connected via a crossbar or is it using the JBus? Is the usable memory
bandwidth available to the HBAs and CPU double the 1,600MB/s, or 3,200MB/s?

> Of course like someone mentioned if all you have is 1 connection using
> postgresql which cannot spawn helper processes/threads, this will be
> limited by the single thread performance which is about 1.2Ghz compared
> on Sun Fire T2000 to AMD64 (Sun Fire X4200) which pretty much has
> similar IO Bandwidth, same size chassis, but the individual AMD64 cores
> runs at about 2.4Ghz (I believe) and max you can get is 4 cores but you
> also have to do a little trade off in terms of power consumption in lei
> of faster single thread performance. So Choices are available with both
> architecture. .However if you have a webserver driving a postgreSQL
> backend, then UltraSPARC T1 might be a better option if you suddenly
> wants to do 100s of db connections. The SunFire T2000 gives you 8 cores
> with 32 threads in all running on the system.

So - OLTP / webserver, that makes sense.

- Luke