rp5430 & and A7173A Utltra320 SCSI HBA

[David Nixon]

Hello,

I will, shortly, be installing an A7173A
dual channel, U320 SCSI, HBA on one of the
"turbo" slots of an rp5430 host.
An external RAID controller, with dual U320 host ports, will then be attached.

As I understand things my (66Mhz) PCI slot won't support U320 speeds.

Should I proactively limit the maximum data transfer rate of the A7173A to 160 MB/s, or leave everything to auto. negotiation ?

Thanks DaveN.

[Sameer_Nirmal · Accepted solution]

Hi David,

The maximum data transfer rate setting is only applicable between the HBA ports and the connected devices. It is nothing to do with underline PCI bus speed. Thus setting it to autonegotiate (default) or 320MB/s are two options in your case. Since you are sure about connecting to U320 array ports, then setting U320 would be more approppriate. Autonegotiate setting would be prefer when the setup is going to change often etc.

The PCI bus speed of the Turbo PCI slot is
250MB/s and it will work at that speed only. In fact, the PCI bus communication from the HBA perspective would be at 250MB/s.

I guess you don't have option to use "Twin Turbo" slots (11&12) right? . If possible, use those slots for better performance.

[David Nixon]

Ta Sameer, for clarifying about HBA data xfer
rate viz a viz the underlying PCI Bus.

There are no "twin turbo" slots on the L1000
so that 250MB/s PCI channel will be the bottleneck
for my set-up - unless I open a
second PCI channel; via an additional HBA..

[Sameer_Nirmal]

David,

Let me understand your question.
You are now referring L1000 (rp5400) server.
Yes, this server doesn't have "twin turbo" slots and the PCI bus bandwidth would be only 250MB/s per slot.

On rp5430 (L1500), each twin turbo PCI slot provides 500MB/s.

A7173A is PCI-X card capable of 133MHz, 64 bit data trnasfer. It is based on PCI-X 1.0 standard. For this card, the max bandwidth/data transfer rate is 1GB/s with 64 bit device.

[David Nixon]

Yes, in my description, I have used a wrong old/new nomenclature mapping for my L1000.

After installing this A7173A card, one of
the rp5400's six turbo slots will be left
for expansion.

[David Nixon]

Only lower the max data transfer rate of an A7173A
HBA if this is required by the external device.