[Beowulf] lspci, PCI-X 133, Mellanox

[Mikhail Kuzminsky]

   I just installed Mellanox InfiniHost MHXL-CF128-T (former 
MTLP23108) NICs into Tyan S2880-based nodes (the location is 1st PCI-X 
133 slot).
lspci -v says about 66 Mhz:

01:03.0 PCI bridge: Mellanox Technology: Unknown device 5a46 (rev a1) 
(prog-if 00 [Normal decode])
	Flags: bus master, 66Mhz, medium devsel, latency 64
	Bus: primary=01, secondary=02, subordinate=02, sec-latency=64
	Memory behind bridge: fc500000-fc7fffff
	Prefetchable memory behind bridge: 00000000eb000000-00000000fc000000
	Capabilities: [70] PCI-X bridge device.

02:00.0 InfiniBand: Mellanox Technology: Unknown device 5a44 (rev a1)
	Subsystem: Mellanox Technology: Unknown device 5a44
	Flags: bus master, 66Mhz, medium devsel, latency 64, IRQ 28
	Memory at fc700000 (64-bit, non-prefetchable) [size=1M]
	Memory at fb800000 (64-bit, prefetchable) [size=8M]
	Memory at f0000000 (64-bit, prefetchable) [size=128M]
	Capabilities: [40] #11 [001f]
	Capabilities: [50] Vital Product Data
	Capabilities: [60] Message Signalled Interrupts: 64bit+ Queue=0/5 
Enable-
	Capabilities: [70] PCI-X non-bridge device.

I found that /usr/include/linux/pci.h knows about 133 Mhz PCI-X.

lspci -vv says:

01:03.0 PCI bridge: Mellanox Technology: Unknown device 5a46 (rev a1) 
(prog-if 00 [Normal decode])
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop- ParErr- 
Stepping- SERR+ FastB2B-
	Status: Cap+ 66Mhz+ UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- 
<TAbort- <MAbort- >SERR- <PERR-
	Latency: 64, cache line size 10
	Bus: primary=01, secondary=02, subordinate=02, sec-latency=64
	Memory behind bridge: fc500000-fc7fffff
	Prefetchable memory behind bridge: 00000000eb000000-00000000fc000000
	BridgeCtl: Parity+ SERR+ NoISA- VGA- MAbort- >Reset- FastB2B-
	Capabilities: [70] PCI-X bridge device.
		Secondary Status: 64bit+, 133MHz+, SCD-, USC-, SCO-, SRD- Freq=3
		Status: Bus=0 Dev=0 Func=0 64bit- 133MHz- SCD- USC-, SCO-, SRD-
		: Upstream: Capacity=0, Commitment Limit=0
		: Downstream: Capacity=0, Commitment Limit=0

and 02:00.0 says also about 66+ Mhz. Sorry, does it means that lspci 
-v output is wrong (has 2 digits only, for example), but lspci -vv is 
correct ?

BTW, is there some reasons to decrease PCI latency in BIOS setup from 
64 (see lspci above) to some more low level ?

Yours
Mikhail Kuzminsky
Zelinsky Institute of Organic Chemistry
Moscow