Possible fake transceivers for X520-DA2, hindering performance?

Question

=== Storage ===

QNAP - TS-EC1279U-RP (12 x 3TB in RAID 6)
Intel - X520-SR2 Trancsiver
AFBR-703SDZ-IN2 (SFP)
i7 Windows 10 with intel ssd 750 (2000 MB/sec)
I have changed all the setting to get the max speed out of the card via the Intel control panel

=== Issues ===

Maximum data transfer from QNAP (READ) to i7 Computer (Write) 2.7Gbps (300MBish)

=== Test ===

Using the command via SHH on the QNAP.

# hdparm -t /dev/md0

I get

Timing buffered disk reads: 3488 MB in 3.00 seconds = 1161.67 MB/sec

This is 12 x 3tb HDDs in RAID 6

I also tired a different SFP cable.

=== Cause ===

Is it possible I have fake Transceiver - AFBR-703SDZ-IN2 (SFP)? I cannot find a way to tell without spending some money on a new set of transceiver. All help is more than welcome.

score 2 · Answer 1 · answered Jun 24 '20 at 19:33

If you are able to boot the X520 on an Ubuntu machine and have the SFP+ Transceiver modules plugged in you can run the following to print out the EEPROM values of the SFP+.

ethtool --module-info ethX

It should return something like this

~$ sudo ethtool --module-info eth10
    Identifier                                : 0x03 (SFP)
    Extended identifier                       : 0x04 (GBIC/SFP defined by 2-wire interface ID)
    Connector                                 : 0x07 (LC)
    Transceiver codes                         : 0x10 0x00 0x00 0x01 0x00 0x00 0x00 0x00
    Transceiver type                          : 10G Ethernet: 10G Base-SR
    Transceiver type                          : Ethernet: 1000BASE-SX
    Encoding                                  : 0x06 (64B/66B)
    BR, Nominal                               : 10300MBd
    Rate identifier                           : 0x02 (8/4/2G Rx Rate_Select only)
    Length (SMF,km)                           : 0km
    Length (SMF)                              : 0m
    Length (50um)                             : 80m
    Length (62.5um)                           : 30m
    Length (Copper)                           : 0m
    Length (OM3)                              : 300m
    Laser wavelength                          : 850nm
    Vendor name                               : Intel Corp
    Vendor OUI                                : 00:1b:21
    Vendor PN                                 : FTLX8571D3BCV-IT
    Vendor rev                                : A
    Option values                             : 0x00 0x3a
    Option                                    : RX_LOS implemented
    Option                                    : TX_FAULT implemented
    Option                                    : TX_DISABLE implemented
    Option                                    : RATE_SELECT implemented
    BR margin, max                            : 0%
    BR margin, min                            : 0%
    Vendor SN                                 : AWB0L1R
    Date code                                 : 160825
    Optical diagnostics support               : Yes
    Laser bias current                        : 7.516 mA
    Laser output power                        : 0.6249 mW / -2.04 dBm
    Receiver signal average optical power     : 0.0008 mW / -30.97 dBm
    Module temperature                        : 26.41 degrees C / 79.55 degrees F
    Module voltage                            : 3.3174 V
    Alarm/warning flags implemented           : Yes
    Laser bias current high alarm             : Off
    Laser bias current low alarm              : Off
    Laser bias current high warning           : Off
    Laser bias current low warning            : Off
    Laser output power high alarm             : Off
    Laser output power low alarm              : Off
    Laser output power high warning           : Off
    Laser output power low warning            : Off
    Module temperature high alarm             : Off
    Module temperature low alarm              : Off
    Module temperature high warning           : Off
    Module temperature low warning            : Off
    Module voltage high alarm                 : Off
    Module voltage low alarm                  : Off
    Module voltage high warning               : Off
    Module voltage low warning                : Off
    Laser rx power high alarm                 : Off
    Laser rx power low alarm                  : On
    Laser rx power high warning               : Off
    Laser rx power low warning                : On
    Laser bias current high alarm threshold   : 13.200 mA
    Laser bias current low alarm threshold    : 4.000 mA
    Laser bias current high warning threshold : 12.600 mA
    Laser bias current low warning threshold  : 5.000 mA
    Laser output power high alarm threshold   : 1.0000 mW / 0.00 dBm
    Laser output power low alarm threshold    : 0.2512 mW / -6.00 dBm
    Laser output power high warning threshold : 0.7943 mW / -1.00 dBm
    Laser output power low warning threshold  : 0.3162 mW / -5.00 dBm
    Module temperature high alarm threshold   : 78.00 degrees C / 172.40 degrees F
    Module temperature low alarm threshold    : -13.00 degrees C / 8.60 degrees F
    Module temperature high warning threshold : 73.00 degrees C / 163.40 degrees F
    Module temperature low warning threshold  : -8.00 degrees C / 17.60 degrees F
    Module voltage high alarm threshold       : 3.7000 V
    Module voltage low alarm threshold        : 2.9000 V
    Module voltage high warning threshold     : 3.6000 V
    Module voltage low warning threshold      : 3.0000 V
    Laser rx power high alarm threshold       : 1.0000 mW / 0.00 dBm
    Laser rx power low alarm threshold        : 0.0100 mW / -20.00 dBm
    Laser rx power high warning threshold     : 0.7943 mW / -1.00 dBm
    Laser rx power low warning threshold      : 0.0158 mW / -18.01 dBm

If it's not a real Intel, it should say so in the vendor name.

I also believe there are windows tools available for Windows from Intel as well, but I'm not sure if it's what you are looking for. Link

Zac67 · Answer 2 · 2017-10-28T07:47:50.817

If the error count in the NIC's statistics doesn't count up the link is fine. You should try some network load testing (iperf or such) with the client and (as far as possible) the NAS.

One possible cause could be that the PCIe slot isn't fast enough to 10GE. The X520-SR2 supports PCIe 2.0 x8 - for 10 Gbit/s throughput you need a PCIe 2.0 x4 slot or PCIe 1.0 x8. Note that this is the number of lanes actually present, not the mechanical slot size.

In other words: no, as long as the link doesn't have - measurable - frame drops, the transceiver has absolutely no impact on throughput. It's a low-level layer 1 device that (more or less) just converts bits to light and back.

Possible fake transceivers for X520-DA2, hindering performance?

2 Answers2