RX2620 difference between PCIX Slot1 and Slot3 , more bandwith ?

[Leonard C.]

Dear All,
There is a rx2620 (hp-ux 11iv2) including Data Protector connected to MSL6030 through as Fiber Connection.
The HBA card is PCI-X 2-channel 2-Gb/s Fibre Channel installed on PCIX Slot 3.
I think if I change the place of HBA Fiber card to PCIX Slot1 , I will have more performance and more data transfer rate.
Any idea?

[TTr]

Slot1 has 2 i/o chammels dedicated to it whereas slots 2,3,4 have only 1. All 4 slots are rated at 133MHz, 64 bit so all of them have the same i/o bandwith but with slot1 the i/o will travel faster inside the bus.
So yes it is a good idea to move the 2port FC HBA to slot 1.
However you may or may not notice any difference in the perfromance.
The real question is, is there enough i/o on the dual port FC HBA now, in slot 3, so that the single i/o bus of slot 3 can not handle?

[Steven E. Protter]

Shalom,

All the specs you need to know and then some.

http://docs.hp.com/en/hw.html#HP%20Integrity%20rx2620%20Server

SEP

[Duncan Edmonstone · Accepted solution]

Will you see any difference?

Each "rope" to the PCI slots is rated at 0.5GB/s

Slots 2, 3 and 4 have only one rope, but slot 1 has 2 so is capable of 1GB/s sustained throughput.

But your card has 2 x 2Gb ports. If these were operating at max throughput that translates into 0.5GB/s:

2Gb/s = 250MB/s

(watch for the translation of bits to bytes)

So it would be likely that your card can't take advantage of the additional bandwidth anyway.

Also don't forget that when writing data to tape, you have to *pull* it from somewhere - where is the data coming from? It's generally more typical to find bottlenecks in backups on the read side of the process rather than the write side...

HTH

Duncan

[Michael Steele_2]

Hi Leaonard C.

I think this is what you want. The slot numbers are indicated by column at the top of the chart. The higher the MHz the faster the I/O throughput.

http://www.docs.hp.com/en/SSM3-EL/slotmatrix.htm

rx2600 TYPE PCI-X 64-bit
133, 66 or 33 MHz PCI-X 64-bit
133, 66 or 33 MHz PCI-X 64-bit
133, 66 or 33 MHz PCI-X 64-bit
133, 66 or 33 MHz
SIZE Full Length Full Length Full Length Full Length
BANDWIDTH
(ROPE #s) Dual 1 GB/s
(4 & 5) Single .5 GB/s
(3) Single .5 GB/s
(2) Single .5 GB/s
(6)
WAKE ON LAN CAPABLE No No No No