2.5Gbit Ethernet for TinyMiniMicro labs

2.5Gbit Ethernet is finally at an affordable price, but modern platforms do not offer much in the way of upgrade paths. Desktop PC motherboards typically dedicate all PCIe lanes to graphics or NVMe, leaving you with tough choices to make if you want to upgrade your network card. The situation is even worse for small form factor and embedded devices.

Or so I thought, until I discovered an M.2 A+E key 2.5Gbit Ethernet card based on the Realtek RTL8125B.

This tiny M.2 2230 card can be installed in the M.2 WiFi slot present on many motherboards. If you were not already using WiFi, this means you have a “free” upgrade path to 2.5Gbit Ethernet, without sacrificing any higher bandwidth PCIe slots. Better still, M.2 A+E keyed slots are commonly available in the “TinyMiniMicro” segment of small-form-factor PCs. This allows you to install 2.5Gbit networking in the Asus PN50, or an HP T640 thin client. You can also find mini-PCIe to M.2 A+E adapters, allowing you to install the NIC in a device that predates M.2.

Also attractive is the price, I bought two for 15.70€/piece (including VAT and shipping) from AliExpress. This is only a small premium over what a full-size PCIe card with an RTL8125B costs (typically around 13€).

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller (rev 05)
        Subsystem: Realtek Semiconductor Co., Ltd. Device 0123
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- SERR- <PERR- INTx-
        Latency: 0, Cache Line Size: 64 bytes
        Interrupt: pin A routed to IRQ 50
        IOMMU group: 8
        Region 0: I/O ports at e000 [size=256]
        Region 2: Memory at fe910000 (64-bit, non-prefetchable) [size=64K]
        Region 4: Memory at fe920000 (64-bit, non-prefetchable) [size=16K]
        Expansion ROM at fe900000 [disabled] [size=64K]
        Capabilities: [40] Power Management version 3
                Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=375mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
                Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
                Address: 0000000000000000  Data: 0000
                Masking: 00000000  Pending: 00000000
        Capabilities: [70] Express (v2) Endpoint, MSI 01
                DevCap: MaxPayload 256 bytes, PhantFunc 0, Latency L0s <512ns, L1 <64us
                        ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 0W
                DevCtl: CorrErr+ NonFatalErr+ FatalErr+ UnsupReq+
                        RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop-
                        MaxPayload 128 bytes, MaxReadReq 4096 bytes
                DevSta: CorrErr+ NonFatalErr- FatalErr- UnsupReq+ AuxPwr+ TransPend-
                LnkCap: Port #0, Speed 5GT/s, Width x1, ASPM L0s L1, Exit Latency L0s unlimited, L1 <64us
                        ClockPM+ Surprise- LLActRep- BwNot- ASPMOptComp+
                LnkCtl: ASPM Disabled; RCB 64 bytes, Disabled- CommClk+
                        ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 5GT/s, Width x1
                        TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
                DevCap2: Completion Timeout: Range ABCD, TimeoutDis+ NROPrPrP- LTR+
                         10BitTagComp- 10BitTagReq- OBFF Via message/WAKE#, ExtFmt- EETLPPrefix-
                         EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
                         FRS- TPHComp+ ExtTPHComp-
                         AtomicOpsCap: 32bit- 64bit- 128bitCAS-
                DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- LTR- 10BitTagReq- OBFF Disabled,
                         AtomicOpsCtl: ReqEn-
                LnkCap2: Supported Link Speeds: 2.5-5GT/s, Crosslink- Retimer- 2Retimers- DRS-
                LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance- SpeedDis-
                         Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
                         Compliance Preset/De-emphasis: -6dB de-emphasis, 0dB preshoot
                LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete- EqualizationPhase1-
                         EqualizationPhase2- EqualizationPhase3- LinkEqualizationRequest-
                         Retimer- 2Retimers- CrosslinkRes: unsupported
        Capabilities: [b0] MSI-X: Enable+ Count=32 Masked-
                Vector table: BAR=4 offset=00000000
                PBA: BAR=4 offset=00000800
        Capabilities: [d0] Vital Product Data
                Not readable
        Capabilities: [100 v2] Advanced Error Reporting
                UESta:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
                UEMsk:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
                UESvrt: DLP+ SDES+ TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
                CESta:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
                CEMsk:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
                AERCap: First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
                        MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
                HeaderLog: 00000000 00000000 00000000 00000000
        Capabilities: [148 v1] Virtual Channel
                Caps:   LPEVC=0 RefClk=100ns PATEntryBits=1
                Arb:    Fixed- WRR32- WRR64- WRR128-
                Ctrl:   ArbSelect=Fixed
                Status: InProgress-
                VC0:    Caps:   PATOffset=00 MaxTimeSlots=1 RejSnoopTrans-
                        Arb:    Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256-
                        Ctrl:   Enable+ ID=0 ArbSelect=Fixed TC/VC=01
                        Status: NegoPending- InProgress-
        Capabilities: [168 v1] Device Serial Number 01-00-00-00-68-4c-e0-00
        Capabilities: [178 v1] Transaction Processing Hints
                No steering table available
        Capabilities: [204 v1] Latency Tolerance Reporting
                Max snoop latency: 0ns
                Max no snoop latency: 0ns
        Capabilities: [20c v1] L1 PM Substates
                L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+ L1_PM_Substates+
                          PortCommonModeRestoreTime=150us PortTPowerOnTime=150us
                L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
                           T_CommonMode=0us LTR1.2_Threshold=306176ns
                L1SubCtl2: T_PwrOn=150us
        Capabilities: [21c v1] Vendor Specific Information: ID=0002 Rev=4 Len=100 
        Kernel driver in use: r8169

iperf3 testing shows that we can achieve consistent results over 2.4Gbit/s between the RTL8125 (M.2 A+E) installed in an HP T640, and the RTL8156 (Framework USB-C module).

Accepted connection from 192.168.10.2, port 45494
[  5] local 192.168.10.1 port 5000 connected to 192.168.10.2 port 45496
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec   294 MBytes  2.47 Gbits/sec
[  5]   1.00-2.00   sec   295 MBytes  2.48 Gbits/sec
[  5]   2.00-3.00   sec   295 MBytes  2.47 Gbits/sec
[  5]   3.00-4.00   sec   295 MBytes  2.48 Gbits/sec
[  5]   4.00-5.00   sec   295 MBytes  2.47 Gbits/sec
[  5]   5.00-6.00   sec   295 MBytes  2.47 Gbits/sec
[  5]   6.00-7.00   sec   295 MBytes  2.48 Gbits/sec
[  5]   7.00-8.00   sec   295 MBytes  2.47 Gbits/sec
[  5]   8.00-9.00   sec   295 MBytes  2.48 Gbits/sec
[  5]   9.00-10.00  sec   295 MBytes  2.47 Gbits/sec
[  5]  10.00-10.00  sec   568 KBytes  2.40 Gbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.00  sec  2.88 GBytes  2.47 Gbits/sec                  receiver

Owners of the lesser powered thin clients should take note: the HP T530 (AMD GX-215JJ) can only manage around 1.6Gbit speeds in iperf3 testing.

You do not typically associate Dupont wires and high bandwidth being a good match, but somehow it works.


Realtek still has a bad reputation in some corners, so for those interested there are also sellers offering the Intel I225-V 2.5Gbit in M.2 B+M 2242 form factor.

The chip revision is SLMNG (B3) which from internet lore seems to be the revision where all the show-stopping bugs at link speeds above 1000M were resolved. I did not notice any instability in my iperf3 testing, the adapter was able to reliably maintain 2.45Gbit/s.

02:00.0 Ethernet controller: Intel Corporation Ethernet Controller I225-V (rev 03)
	Subsystem: Intel Corporation Device 0000
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- SERR- <PERR- INTx-
	Latency: 0, Cache Line Size: 64 bytes
	Interrupt: pin A routed to IRQ 50
	IOMMU group: 8
	Region 0: Memory at fe700000 (32-bit, non-prefetchable) [size=1M]
	Region 3: Memory at fe800000 (32-bit, non-prefetchable) [size=16K]
	Expansion ROM at fe600000 [disabled] [size=1M]
	Capabilities: [40] Power Management version 3
		Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=1 PME-
	Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
		Address: 0000000000000000  Data: 0000
		Masking: 00000000  Pending: 00000000
	Capabilities: [70] MSI-X: Enable+ Count=5 Masked-
		Vector table: BAR=3 offset=00000000
		PBA: BAR=3 offset=00002000
	Capabilities: [a0] Express (v2) Endpoint, MSI 00
		DevCap:	MaxPayload 512 bytes, PhantFunc 0, Latency L0s <512ns, L1 <64us
			ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset+ SlotPowerLimit 0W
		DevCtl:	CorrErr+ NonFatalErr+ FatalErr+ UnsupReq+
			RlxdOrd- ExtTag- PhantFunc- AuxPwr- NoSnoop+ FLReset-
			MaxPayload 128 bytes, MaxReadReq 512 bytes
		DevSta:	CorrErr+ NonFatalErr- FatalErr- UnsupReq+ AuxPwr+ TransPend-
		LnkCap:	Port #3, Speed 5GT/s, Width x1, ASPM L1, Exit Latency L1 <4us
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes, Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 5GT/s, Width x1
			TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Range ABCD, TimeoutDis+ NROPrPrP- LTR+
			 10BitTagComp- 10BitTagReq- OBFF Not Supported, ExtFmt- EETLPPrefix-
			 EmergencyPowerReduction Not Supported, EmergencyPowerReductionInit-
			 FRS- TPHComp- ExtTPHComp-
			 AtomicOpsCap: 32bit- 64bit- 128bitCAS-
		DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis- LTR- 10BitTagReq- OBFF Disabled,
			 AtomicOpsCtl: ReqEn-
		LnkCtl2: Target Link Speed: 5GT/s, EnterCompliance- SpeedDis-
			 Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
			 Compliance Preset/De-emphasis: -6dB de-emphasis, 0dB preshoot
		LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete- EqualizationPhase1-
			 EqualizationPhase2- EqualizationPhase3- LinkEqualizationRequest-
			 Retimer- 2Retimers- CrosslinkRes: unsupported
	Capabilities: [100 v2] Advanced Error Reporting
		UESta:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
		UEMsk:	DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
		UESvrt:	DLP+ SDES+ TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
		CESta:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr-
		CEMsk:	RxErr- BadTLP- BadDLLP- Rollover- Timeout- AdvNonFatalErr+
		AERCap:	First Error Pointer: 00, ECRCGenCap+ ECRCGenEn- ECRCChkCap+ ECRCChkEn-
			MultHdrRecCap- MultHdrRecEn- TLPPfxPres- HdrLogCap-
		HeaderLog: 00000000 00000000 00000000 00000000
	Capabilities: [140 v1] Device Serial Number 88-c9-b3-ff-ff-b5-19-bc
	Capabilities: [1c0 v1] Latency Tolerance Reporting
		Max snoop latency: 0ns
		Max no snoop latency: 0ns
	Capabilities: [1f0 v1] Precision Time Measurement
		PTMCap: Requester:+ Responder:- Root:-
		PTMClockGranularity: 4ns
		PTMControl: Enabled:- RootSelected:-
		PTMEffectiveGranularity: Unknown
	Capabilities: [1e0 v1] L1 PM Substates
		L1SubCap: PCI-PM_L1.2- PCI-PM_L1.1+ ASPM_L1.2- ASPM_L1.1+ L1_PM_Substates+
		L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
		L1SubCtl2:
	Kernel driver in use: igc

I have not been able to find anyone selling the I225-V in the M.2 A+E form factor. However, you can adapt the M.2 2242 B/M key to an A+E key with an inexpensive passive adapter.

Performance is unaffected, but you should check that you have physical clearance for such an adapter as it extends the card length from 42mm to 53mm. This prevents one from installing the I225-V in the HP T530, as there is insufficient physical clearance for the card with the M.2 A+E adapter.

Finally, the I225-V M.2 designs I have seen are using larger perpendicular headers as compared to the Realtek, meaning they are less likely to fit in small/thin devices like the HP T640 thin client. Given the choice, I would stick to the Realtek for M.2 A+E applications rather than adapting the Intel I225-V.

HP ThunderBolt 120W G4 Dock teardown

I bought an HP ThunderBolt 120W G4 dock (4J0A2AA) because the Dell TB16 I have been using for years does not work well with the Framework Laptop 13″ (13th Gen; i5-1340P).

The Dell TB16 is recognized by the Framework Laptop and does function, however only the mini-DisplayPort output works. Despite repeated attempts, I could not make multiple monitor outputs function with the Framework Laptop and the TB16, which is annoying as I had two displays (DisplayPort and mini-DisplayPort) running at 4K60 from the XPS 9570.

HP ThunderBolt 120W G4 dock, HP product image

The HP Thunderbolt G4 dock is quite new and supports USB4 on the upstream port to the host (the dock ports support USB 3.2 Gen 2). Multiple displays work with the Framework Laptop: DisplayPort and HDMI outputs both work simultaneously with my two 4K60 displays. The dock is also able to output 4K60 to both monitors from a Lenovo ThinkPad X13 Gen 2 AMD, which was a pleasant surprise given that the X13 Gen 2 does not have Thunderbolt (only DP-Alt mode over USB-C).


lspci

56:00.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge 2020] (rev 03)
57:00.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge 2020] (rev 03)
57:01.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge 2020] (rev 03)
57:02.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge 2020] (rev 03)
57:03.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge 2020] (rev 03)
57:04.0 PCI bridge: Intel Corporation Thunderbolt 4 Bridge [Goshen Ridge 2020] (rev 03)
7f:00.0 Ethernet controller: Intel Corporation Ethernet Controller (2) I225-LMvP (rev 03)

lsusb

03f0:0488 HP, Inc HP Thunderbolt Dock G4
03f0:2488 HP, Inc USB4206 Smart Hub
03f0:3488 HP, Inc USB7206 Smart Hub
03f0:4488 HP, Inc USB2734
03f0:5488 HP, Inc USB5734
1d5c:5801 Fresco Logic USB2.0 Hub
8087:0b40 Intel Corp. USB3.0 Hub

The dock also works as a USB-C docking station, with the following USB devices present in that mode:

03f0:0488 HP, Inc HP Thunderbolt Dock G4
03f0:2488 HP, Inc USB4206 Smart Hub
03f0:3488 HP, Inc USB7206 Smart Hub
03f0:4488 HP, Inc USB2734
03f0:5488 HP, Inc USB5734
0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter
1d5c:5801 Fresco Logic USB2.0 Hub
8087:0b40 Intel Corp. USB3.0 Hub

I was able to find a teardown for the HP ThunderBolt G2 dock, but I have not yet found any juicy details about the G4. So, here we go.

One Philips screw (on the base at rear) and the bottom slides off (gently lift and slide in the direction of the Thunderbolt cable).

Remove the two Philips screws securing the collar over the Thunderbolt cable and swing the collar up. You can gently pull it to remove it from the base, however this is not required.

The Thunderbolt cable may appear “fixed” however it is just secured in place, so if you ever have a dock with a ruined Thunderbolt cable, do not throw it away as the cable can be replaced!

Remove the four Philips screws securing the bottom of the dock. There are no plastic clips around the outside of the base, so you can gently lift it out.

Remove the three recessed Philips screws to remove the dock components from the plastic housing.

(Optional) If you need to release the bottom PCB (MB) from the heat spreader, remove the four Philips screws highlighted above. It is not necessary to remove these screws to remove the assembly from the plastic housing. There are several board-to-board connectors between the MB and DB PCBs inside the docking station; you need to remove the entire internal assembly from the plastic housing before you attempt to remove the bottom PCB.

Be mindful of the connector to the top power button when removing the internal component assembly.

To replace the fan (Delta Electronics NS55B00-17E11), remove the two Philips screws and unplug it from the top PCB (DB).

To remove the top PCB (DB) from the heat spreader, remove the four Philips screws highlighted above.


MB PCB bottom (full resolution PCB photo)

U3305: winbond W25Q80DVNIG (under black plastic, beside HP female power connector)

MB PCB top (full resolution PCB photo)

U2400/U2403: Infineon CYPD5236-96BZXI
U2600: Microchip USB7206
U????: Synaptics VMM5323BJGB1 (silk screen is obscured by underfill on my unit)
U3306: Pericom PI3WVR12412
U4000: Diodes Incorporated PI6C557-03BLE
U2900: Parade Tech PS8802
U2700: Intel JHL8440
U2701: winbond W25Q80DVSIG
U3500: fresco logic FL5801
U3501: winbond W25Q16JV

DB PCB bottom (full resolution PCB photo)

PCB silk screen:

HOOK20-PMV-HSB
6050A3310901-DB-A01
2021-11-02

U2550: Microchip USB5744
U453: winbond W25Q16JV
U4002: winbond W25Q64JVSIQ
CN9002: Power button header (power button PCB silk screen: 6050A3311201-PWRBUTTON-A01)

DB PCB top (full resolution PCB photo)

U451: P13L 2500ZHE 2136GG (PI3L?)
U400: Realtek RTL8153
U4003: Infineon CY7C65219-40LQXI
U5000: Diodes Incorporated PI6C557-03BLE
U450: Intel I225 (SLNNJ)
CN9001: Fan header

Fan: Delta Electronics NS55B00-17E11 (5V, 0.6A)

Power supply:
Output: 19.5V, 6.15A (120W)
Regulatory Model: TPN-DA19
HP Part No: L56786-013
HP Spare: L57117-001

Fujitsu TX1320 M3

As with many purchases, this one began with a thread on ServeTheHome. Given my previous work on the Fujitsu TX140 S2 motherboard, how could I refuse the offer of a barebones Fujitsu TX1320 M3 for only 29€?

Fujitsu TX1320 M3

The TX1320 M3 is slightly too tall to fit within 2U, measuring at 398x340x98mm. Those wishing to place it on a rack shelf, you will need to budget 2.5U for the unit.


My TX1320 M3 came with BIOS 1.19.0, which does not support Xeon v5 CPUs. Not knowing the iRMC S4 password, it was not possible to flash a newer BIOS via iRMC. But, the SOIC8 that contains the BIOS was easily located (on the front of the motherboard, near to the INTR header and internal USB3 port).

The BIOS update D3373-B1.ROM file provided by Fujitsu is exactly 8388608 bytes. So, updating the BIOS requires only a ch341a programmer and a SOIC8 chip-clip. Dump the current BIOS, replace the last 8MB with D3373-B1.ROM downloaded from Fujitsu, and reflash to have support for a Xeon v5 CPU:

$ sudo flashrom -p ch341a_spi -c "N25Q128..3E" -r TX1320.bin
$ dd if=D3373-B1.ROM of=TX1320.bin bs=1M seek=8
$ sudo flashrom -p ch341a_spi -c "N25Q128..3E" -w TX1320.bin

After booting Linux, it is easy to reset the iRMC S4 password using ipmitool.


iRMC S4 on the TX1320 M3 motherboard has the UART routed to an unpopulated header and has the same parameters as the TX140 S2: 38400n8.

The pin beside UART Tx is not a ground, it’s a GPIO from the Pilot III. Pin 3 of the INTR header (closest to the USB port) is GND and fits a 2.54mm prototype wire. The iRMC S4 bootlog is available in this gist.

UART access does not instantly make you god of iRMC S4. After booting, remmman is running on the uart, so without knowing a valid username and password, you can’t gain access. u-boot is built with the dhcp and tftpboot commands, so you could potentially boot a modified image from the network that would give you root access (untested).

The GPL components of iRMC S4 are available on GitHub.


The Fujitsu 250W power supply (Model: CPB09-045E, S26113-E564-V71-01) has the dimensions 93x71x187mm, which should allow for the installation of a TFX PSU (85x65x175mm) in the chassis with minimal modification. Being a Fujitsu workstation, the power supply pin-out is identical to the TX140 S2.

The SATA power connector on the motherboard is a Molex 5559 2×4 with the following pinout (top view, looking toward PCB):

GND* 5V GND 12V*
GND* 5V* GND* 12V*

The 2.5″ backplane (Fujitsu P/N: A3C40176096) has a Molex 5559 2×2 power connector with the following pinout (top view, looking toward PCB):

GND GND*
12V 12V*

Note that only the the conductors marked with * are populated in the Fujitsu wiring harness.


The 16 pin front-panel header has the same pinout as the TX140 S2:

As expected, we find two I2C EEPROMs (TSSOP8) and a Texas Instruments LM75 temperature sensor (VSSOP8) on the front-panel PCB (Fujitsu P/N: A3C40167342).

TX1320 M3 front-panel PCB


The TX1320 M3 noise profile is excellent, it is slightly audible during POST, but inaudible once booted into the OS (Linux).

The CPU cooler (V26898-B1003-V1/A3C40175673/A3C40175674) is a small dual heat pipe design with two towers with a fan (Delta AFB0712HHB) sandwiched between. The hot-swap 2.5″ drive bay has a single fan AVC DA07020B12M installed in a toolless plastic bracket. The design expects one fan per backplane, so if you install a second backplane to expand to eight 2.5″ drives, a second fan and bracket may be necessary.


lspci output:

00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Host Bridge/DRAM Registers (rev 07)
00:14.0 USB controller: Intel Corporation 100 Series/C230 Series Chipset Family USB 3.0 xHCI Controller (rev 31)
00:14.2 Signal processing controller: Intel Corporation 100 Series/C230 Series Chipset Family Thermal Subsystem (rev 31)
00:16.0 Communication controller: Intel Corporation 100 Series/C230 Series Chipset Family MEI Controller #1 (rev 31)
00:16.1 Communication controller: Intel Corporation 100 Series/C230 Series Chipset Family MEI Controller #2 (rev 31)
00:17.0 SATA controller: Intel Corporation Q170/Q150/B150/H170/H110/Z170/CM236 Chipset SATA Controller [AHCI Mode] (rev 31)
00:1c.0 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #5 (rev f1)
00:1c.5 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #6 (rev f1)
00:1c.6 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #7 (rev f1)
00:1f.0 ISA bridge: Intel Corporation C236 Chipset LPC/eSPI Controller (rev 31)
00:1f.2 Memory controller: Intel Corporation 100 Series/C230 Series Chipset Family Power Management Controller (rev 31)
00:1f.4 SMBus: Intel Corporation 100 Series/C230 Series Chipset Family SMBus (rev 31)
01:00.0 VGA compatible controller: Matrox Electronics Systems Ltd. MGA G200e [Pilot] ServerEngines (SEP1) (rev 05)
01:00.1 Co-processor: Emulex Corporation ServerView iRMC HTI
02:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)
03:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)

For those looking to install 32GB unbuffered DIMMs, unfortunately there is no support for that on the TX1320 M3. The capacity is recognized, and I was able to open UEFI Setup, as well as boot the Arch Linux installer, however if the CPU addresses beyond 16GB a non-maskable interrupt (NMI) is generated and the system halts.


The TX1320 M3 is not a compelling upgrade for those who already have something like the TX140 S2: performance and power consumption are quite similar between the two generations. Only if you need more bandwidth than PCIe 2.0 offers would upgrading to the TX1320 M3 (PCIe 3.0 x8/x8/x4/x1) make sense over the TX140 S2 (PCIe 3.0 x8, PCIe 2.0 x8/x4/x1).

Power consumption:

  • 4W when powered off (iRMC powered, management NIC connected at 1000MBit)
  • 16W when idle in Linux (Xeon E3-1220 v5, 2x16GB DIMMs, 16GB boot SSD, 1xEthernet, iRMC management Ethernet)

If you do not already have a Fujitsu and are interested in a low-power server, then the TX1320 M3 (or TX1330 M2 which also uses the D3373 motherboard) is a good choice. Of course, iRMC S4 is onboard, so with a little effort you can have an Advanced license 😉

Given that the D3373 motherboard is mATX compatible, I consider it a worthwhile purchase for the chassis alone. Note that the IO shield is integrated into the chassis, so you would need to remove this with a rotary saw to install another motherboard.

D3373-B1.ROM: 8cf71990597df6561b9c7c3e2c1b7e4c4b373a7a63271ba1a93bab9f50e0903f


(The following content was added in January 2024)

If you want to expand the capacity of the system to 8 drives, you will need to purchase another backplane as the one shipped in the system only supports four 2.5″ drives.

I can confirm that the Fujitsu 8 port backplane (P/N: A3C40173252) fits mechanically with zero modifications.

The 8 port backplane can be found for the same price (29€) as most sellers are asking for the 4 port model, and simplifies the cabling. You only need one power cable and one I2C cable with the 8 port backplane, although two of each cable are provided in the TX1320. You will need an additional SATA/SAS controller though, as the D3373 has only one Mini-SAS HD connector for up to 4 devices.

You can use the original Molex 5559 power cable (2×2 positions; 2 populated) from the TX1320 with the 8 port backplane without modification; below is the pinout of the original power cable (2×3 positions; 6 populated) marked on the PCB as X40:

A3C40173252 SAS backplane power receptacle (X40)

Older revisions of the backplane also have a Micro-Fit 3.0 (Molex 430450412) populated on the PCB as X17 which offers 12V and 5V voltage outputs. Note that the below pinout is for the cable, not the X17 receptacle:

A3C40173252 X17 cable pinout

Note that you still need to provide cooling for the additional drive bays, which cannot easily be done as the plastic fan duct has no official part number (as noted by Artur in the comments).