On Thu, 3 Jul 2008, Roger Heflin wrote:
Justin Piszcz wrote:
On Thu, 3 Jul 2008, Jeff Garzik wrote:
Justin Piszcz wrote:
Well, given that pcie x1 is max 250MB/second, and a number of pcie cards are
not native (they have a pcie to pci converter between them), "dmidecode -vvv"
will give you more details on the actual layout of things, and given that I
have seen several devices actually run slower by having the ability to
oversubscribe the bandwidth that is available and seemingly actually run
slower because of this ability, that may have some bearing, Ie 2 slower
disks may be faster than 2 fast disks on the pcie just because they don't
oversubscribe the interfere. And given that if there is a pci converter that
may lower the overall bandwidth even more, and cause the issue. If this was
old style ethernet I would have though collisions, but it must just come down
to the arbitration setups not being carefully designed for high utilization,
and high interference between devices.
Roger
I have ordered a couple 4 port boards (that are PCI-e x4), my next plan
of action to acquire > 600MiB/s is as follows:
Current:
Mobo: 6 drives (full speed)
Silicon Image (3 cards, 2 drives each)
Future:
Mobo: 6 drives (full speed)
Silicon Image (3 cards, 1 drive each)
Four Port Card in x16 slot (the 3 remaining drives)
This should in theory allow 1000 MiB/s..
--
# dmidecode -vvv
dmidecode: invalid option -- v
Assume you mean lspci:
05:00.0 RAID bus controller: Silicon Image, Inc. SiI 3132 Serial ATA Raid II Controller (rev 01)
Subsystem: Silicon Image, Inc. Device 7132
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0, Cache Line Size: 64 bytes
Interrupt: pin A routed to IRQ 16
Region 0: Memory at e0104000 (64-bit, non-prefetchable) [size=128]
Region 2: Memory at e0100000 (64-bit, non-prefetchable) [size=16K]
Region 4: I/O ports at 2000 [size=128]
Expansion ROM at e0900000 [disabled] [size=512K]
Capabilities: [54] Power Management version 2
Flags: PMEClk- DSI+ D1+ D2+ AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
Status: D0 PME-Enable- DSel=0 DScale=1 PME-
Capabilities: [5c] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
Address: 0000000000000000 Data: 0000
Capabilities: [70] Express (v1) Legacy Endpoint, MSI 00
DevCap: MaxPayload 1024 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
ExtTag- AttnBtn- AttnInd- PwrInd- RBE- FLReset-
DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
MaxPayload 128 bytes, MaxReadReq 512 bytes
DevSta: CorrErr+ UncorrErr+ FatalErr- UnsuppReq+ AuxPwr- TransPend-
LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s, Latency L0 unlimited, L1 unlimited
ClockPM- Suprise- LLActRep- BwNot-
LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
Capabilities: [100] Advanced Error Reporting <?>
Kernel driver in use: sata_sil24
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