[arch-general] Installed 3Com 3c595 rate dropped from 11.59MB/s to 3.27MB/s -- howto fix?

David C. Rankin drankinatty at suddenlinkmail.com
Tue Jul 26 14:19:02 EDT 2011


Guys,

   This is a new one on me. I have been using the onboard LAN 
(RTL-8139/8139C/8139C+ (rev 10)) for several years and always got great 
transfer rates:

01:0b.0 Ethernet controller: Realtek Semiconductor Co., Ltd. 
RTL-8139/8139C/8139C+ (rev 10)
         Subsystem: Giga-byte Technology GA-7VM400M/7VT600 Motherboard
         Flags: bus master, medium devsel, latency 32, IRQ 16
         I/O ports at 8000 [size=256]
         Memory at e8000000 (32-bit, non-prefetchable) [size=256]
         Capabilities: [50] Power Management version 2
         Kernel driver in use: 8139too
         Kernel modules: 8139too, 8139cp

10:02 providence:~/arch/pkg/new-110718/virtualbox_bin> rsync -uav --progress 
virtualbox_bin-4.0.12-1-i686.pkg.tar.xz phoenix:/srv/http/dl/arch/i686
sending incremental file list
virtualbox_bin-4.0.12-1-i686.pkg.tar.xz
     55685508 100%   11.59MB/s    0:00:04 (xfer#1, to-check=0/1)

sent 55692427 bytes  received 31 bytes  10125901.45 bytes/sec
total size is 55685508  speedup is 1.00

   I was having intermittent lockups during large file transfers (memtest is 
fine), so I thought I would change the NIC. I installed a 3Com Corporation 
3c595 100BaseTX [Vortex] card and tested the throughput. The throughput is 1/3 
what I was getting with the Realtek card:

01:07.0 Ethernet controller: 3Com Corporation 3c595 100BaseTX [Vortex]
         Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- 
Stepping- SERR- FastB2B- DisINTx-
         Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- 
<TAbort- <MAbort- >SERR- <PERR- INTx-
         Latency: 248 (750ns min, 2000ns max)
         Interrupt: pin A routed to IRQ 19
         Region 0: I/O ports at 8000 [size=32]
         [virtual] Expansion ROM at 80000000 [disabled] [size=64K]
         Kernel driver in use: 3c59x
         Kernel modules: 3c59x

12:47 providence:~/arch/pkg/new-110718/virtualbox_bin> rsync -uav --progress 
virtualbox_bin-4.0.12-1-i686.pkg.tar.xz phoenix:~/tmp
sending incremental file list
virtualbox_bin-4.0.12-1-i686.pkg.tar.xz
     55685508 100%    3.27MB/s    0:00:16 (xfer#1, to-check=0/1)

sent 55692427 bytes  received 31 bytes  3182426.17 bytes/sec
total size is 55685508  speedup is 1.00


   I searched the forums and I've tried ethtool in setting speed, duplex and 
autoneg, but it makes no difference. i.e.:

ethtool -s eth0 speed 100 duplex full autoneg off

   What else can I try to get this card working correctly?  All light 
indications on the card and the switch it is connected to show a 100TX 
connection is being made. What say the gurus?

-- 
David C. Rankin, J.D.,P.E.


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