The ASUS KGPE-D16 is a AMD Family 10h/15h, dual-CPU server and workstation motherboard released end of 2012. It is well supported and stable under coreboot. For some minor caveats please see information below.
A basic system diagram is available in the official manual, Appendix A.1 and has been confirmed to match the hardware shipping from ASUS. Not indicated are the PCIe lane widths for the gigabit network controller, which are both x1. All legacy PCI devices share the same bus, and partially due to this design the SP5100 has issues with bridging high-bandwidth PCI peripherals. As such, an external PCI-PCIe bridge is recommended should you need to interface a high bandwidth legacy PCI device to this system; ASMedia controllers have been verified to function correctly.
Northbridge functions are distributed between the CPU internal northbridge and the SR5690 northbridge, which is effectively a HyperTransport to ALink/PCIe translator and switch. There is a separate SP5100 southbridge device, adjacent to the northbridge and residing under the smaller heatsink of the two. This device provides all traditional southbridge services including the LPC bridge and SATA controllers. All southbridge-destined messages, including CPU-originated power state control messages over HyperTransport, pass through the CPU northbridge and are routed to the southbridge via the SR5690 northbridge device.
Incidentally, this design places the IOMMU, which is part of the SR5690, in the correct location to properly shield the main CPU from all unauthorized traffic. If the southbridge connected directly to a HyperTransport link there would be no way to prevent unauthorized DMA from legacy PCI devices connected to the southbridge, or even from the southbridge's embedded microprocessor.
- Must be operated with 1x EPS12V cable for operations with one CPU, and 2x EPS12V cables for two CPUs
- coreboot must be flashed externally when migrating from the proprietary BIOS. Alternatively the ROM chips can be easibly swapped with another ROM chip. After booting the new contents of the ROM at least once, flashrom can safely reprogram the ROM under GNU/Linux
- When migrating from the proprietary BIOS, after flashing coreboot the CMOS memory MUST be cleared. Failing to clear the CMOS will typically result in odd hangs during the boot process
- Enabling the serial console or EHCI debug console will drastically increase the time needed to boot
- Having a serial console log level above 2 will drastically increase the time required for booting
- All CPUs are split in to two NUMA nodes as they are two 2/4/6/8 core CPU's in one package, memory is divided based on NUMA nodes (1 6282SE 16 core CPU, 2 Nodes, 32GB RAM, 16GB per node) and not properly aligning NUMA RAM will result in drastically decreased performance
- Turbo 2 and power saving seems to require a tickless system to function (nohz=on in the kernel cmdline), otherwise the extra cores are always woken up and will never enter CC6
For general info regarding fancontrol please see fancontrol.
There are two ways to control fans on a KGPE-D16:
- Using openBMC with an ASUS BMC module
- Fancontrol/pwmconfig to control your fans from via your GNU/Linux operating system
Specific notes regarding fancontrol on KGPE-D16
openBMC Port on KGPE-D16
Install the OpenBMC port beta to the ASMB4-iKVM or ASMB5-iKVM modules that come with the main KGPE-D16 retail SKU, this provides fan control and a variety of other cool remote management features.
Limited thermal management with coreboot and coreboot-based BIOS replacements on KGPE-D16
The thermal management hardware of the KGPE-D16 is somewhat unusual and limited. It supports both 4-pin and 3-pin fans, however even though it contains a PWM controller with 8 hardware channels, ASUS has only wired up two PWM channels to the fan connectors. To make matters worse, PWM channel 1 is routed to all 4-pin fans while PWM channel 2 is routed to all 3-pin fans.
TL;DR: If you have two CPU HSFs installed, both fans will run at the same speed. We recommend using the thermal sensors of the warmest CPU in the system depending on your setup.
|Max RAM||256 GB||128GB normal, 192GB via special configuration, 256 for Vikings builds - See below|
|PCI-e slots||4||5 physical, 4 concurrent|
|PCI slots||1||Via PCI Bridge that also connects onboard AST graphics chip|
|Other Expansion Slots||1 PIKE||ASUS Proprietary I/O Expansion Slot, Insert PIKE RAID card for second half of the motherboard SATA/SAS ports - half of the "PIKE" connector is simply a reversed PCI-e x4 slot.|
|EEPROM Type||DIP 8 SPI Socket|
|Factory EEPROM Size||2MB|
|Max EEPROM Size||16MB tested|
|TPM||YES||Compatibility with TPM modules that fit ASUS TPM header. (Connected over LPC.) Note these modules are proprietary. Owner controlled CRTM|
|Crossfire XDMA||???||Has ACS and dual PCI-e 2.0 x16 slots, so it should work (reported working on vendor bios, need tester for coreboot)|
|Blob Free Operations||YES|
|Native GFX Init||Partial||Text Mode Only||Now features proper EDID parsing.|
|BMC||Open Source||OpenBMC - open source remote management - Available for KGPE-D16 and KCMA-D8 boards via installation to the ASUS ASMB4-iKVM or ASMB5-iKVM module.|
|IOMMU||YES||v1.26 with Interrupt Remapping|
|IOMMU for Graphics||YES||Near-Native 3D gaming graphics performance with proper software configuration|
|SR-IOV||???||Coreboot doesn't support SR-IOV|
|PCI-e ARI||???||Required for more than 8 SR-IOV VF per device, AMD's docs say the chipset supports it however there are no firmware implementations that feature it.|
OpenBMC - Open Source Remote Management
Raptor Engineering worked on porting OpenBMC to the KGPE-D16 and KCMA-D8 under a crowdfunded contract. The ASUS ASMB4-iKVM or ASMB5-iKVM modules are required to use it.
More info here: https://www.raptorengineering.com/coreboot/kgpe-d16-bmc-port-status.php
Family 10h (Opteron 6100) processors do not currently support the isochronous mode required to enable the IOMMU, Family 15h (Opteron 6200 & 6300) processors work well with the IOMMU enabled.
In addition to the 1 or 2 main CPUs, there are no less than three known secondary processors present on the mainboard. All are disabled when running under coreboot.
- There is a very poorly documented microprocessor inside the SR5690; purpose and type unknown. It is believed this processor requires a firmware upload from the main platform firmware or via JTAG in order to start execution.
- A single 8051 processor core is present inside the SB700 southbridge. It normally handles errata related to power states and may also be responsible for the blinking power LED in S3 suspend under the proprietary BIOS. It is believed accesses made by this processor are responsible for the flashrom write failure when the board is booted from the proprietary BIOS. This processor also requires a firmware upload from the main platform firmware or via JTAG in order to start execution.
- The BMC has an integrated ARM core. This is disabled by pin strap when the BMC firmware module is not installed.
Some processors may be present on or activated by add-on modules:
- The optional PIKE add-on cards use ARM cores to handle the SAS protocol, though this firmware is directly loaded from a Flash chip on the module and does not involve any non-local components (e.g. the main CPU never touches the firmware on these modules outside of a manual reflash operation). Raptor Engineering is currently unaware of any SAS controllers that operate without a secondary processor or use libre firmware; the protocol is simply too complex to handle via a mask ROM, and as there are only one or two suppliers of SAS controllers there is very little incentive to release the source code to the firmware. Writing a libre firmware to replace the existing firmware may technically be possible, however it is extremely unlikely this will ever happen due to the man-decades required.
- Installing an ASUS iKVM firmware module will activate the ARM core in the BMC, which has full system access to all peripherals and possibly memory. It is not recommended to use this module as the firmware is both highly privileged and proprietary, and is known to contain at least one critical security bug.
Non-free Software & Security Alert
Vikings recommends the Opteron 6200 CPU series for their IOMMU support and stable operation without microcode updates (non-free software) tested in in more than ~500 CPU years in-house under heavy load without incident.
Vikings does NOT recommend using Opteron 6100 series because of missing IOMMU support (security!) or the Opteron 6300 series because it requires microcode updates for stability and IOMMU to work, a gain-root-via-NMI-exploit fix and other issues that can be found in AMD's Fam15h errata.
|Processor sold by AMD||Part Number||Cores||Requires microcode updates for secure operation (ref)||Notes|
|Opteron 6328||OS6328WKT8GHK or OS6328WKT8GHKWOF||8||Yes|
|Opteron 6287SE (2nd fastest)||16||No|
The following RAM models and configurations have been tested by either Raptor Engineering or a third party and are know to work as of the stated GIT revision.
|Manufacturer||Model||Max working RAM / CPU||Size||Speed||Type||ECC||Populated Slots||CPU||Mainboard Type||Firmware|
|Vikings||Vikings||256GB||DDR3-1600||Registered||Yes||All||All 62xx/63xx Opteron CPUs||All||coreboot|
|Micron||36KSF2G72PZ-1G4E1 (N/A)||16GB||DDR3-1333||Registered||Yes||A2 / C2||Opteron 6378||coreboot 2268e0d or later|
|Micron||MT36KSF1G72PZ-1G6M1FF||32GB||8GB||DDR3-1600||Registered||Yes||All orange slots||Opteron 6262HE||1.03G||Internal development version of coreboot|
|Micron / HP||MT36JSF2G72PZ-1G6E1LG (HP: 672612-081)||32GB||16GB||DDR3-1600||Registered||Yes||A2 / C2 / E2 / G2||Opteron 6276||1.03G||Libreboot 20160907|
|Hynix/Hyundai||HMT151R7BFR4C-H9||16GB||4GB||DDR3-1333||Registered||Yes||A2 / C2 / E2 / G2
A2 / B2 / C2 / D2
|Opteron 6276||1.03G||Libreboot 20160907|
|Kingston||9965525-055.A00LF||8GB||DDR3-1600||Unbuffered||Yes||A2 / C2 / E2 / F2||Opteron 6328||coreboot 9fba481|
|Kingston||KVR16R11D4/16 (9965516-483.A00LF)||64GB||16GB||DDR3-1600||Registered||Yes||All orange slots (128GB)||Opteron 6278/6262HE||Libreboot 20160907|
|Kingston||KVR16R11D4K4/64I (9965516-477.A00LF)||64GB||16GB||DDR3-1600||Registered||Yes||All orange slots (128GB)||Opteron 6278/6262HE/6284SE||Libreboot 20160907|
|crucial ("crucial by Micron")||CT16G3ERSLD4160B (MT36KSF2G72PZ-1G6P1NE)||64GB||16GB||DDR3-1600||Registered||Yes||All orange slots (128GB)||Opteron 6278/6282SE/6284SE/6287SE||1.03G, 1.04||Libreboot 20160907|
|Micron||MT36KSF2G72PZ-1G6E1FE||64GB||16GB||DDR3-1600||Registered||Yes||All orange slots||Opteron 6378||1.04||Internal development version of coreboot (2017)|
|Micron||MT36KSF2G72PZ-1G6N1KG||64GB||16GB||DDR3-1600||Registered||Yes||All orange slots||Opteron 6378||1.04||Internal development version of coreboot (2017)|
|crucial ("crucial by Micron")||CT16G3ERSLD4160B (MT36KSF2G72PZ-1G6P1NE)||192GB||16GB||DDR3-1600||Registered||Yes||Leave H1, H2, G1, G2 empty (see page 2-16 in the ASUS manual), LVDDR3_SEL1 can be set to "Force 1.35V"||Opteron 6278/6282SE/6284SE/6287SE||1.03G, 1.04||coreboot d6735b0|
Max. RAM Limitations
192 GB RAM limitation, up to 256 GB RAM with Vikings builds
It has been reported that the KGPE-D16 doesn't work with more than 192 GB RAM, or at least is very picky about the specific model. To make more DIMMs work on the KGPE-D16 this would need further work by coreboot developers, which is unlikely going to be funded at this point given the status on coreboot and the age of the mainboard.
CPU0 can be fully populated, however CPU1 has marginal routing. In order to use 192 GB of RAM it's necessary to either leave the two DIMM slots next to the CPUs unpopulated or the 4 closest on CPU1 unpopulated. In each case RAM training may work well, but system can be unstable. Stress-testing recommended. Behavior may be contingent on the boards PCB revision.
Vikings can build your KGPE-D16 based workstation or server with 256 GB of ECC RAM by using carefully selected and tested DIMMs. Let us know if you're interested in such a build.
Although these are standard DIMMs that you can normally get on the free market, we use them to finance our expensive DIMM tests that we performed for the KGPE-D16. We therefore ask for your understanding that we cannot publish this at the moment. We will do this as soon as the costs are recovered. With the current rate of sales we expect this to be the case in late 2024
Miscellaneous Known Issues and Workarounds
No Boot Menu with Petitboot
If your KGPE-D16 server or workstation is equipped with a discrete graphics processor, the on-board VGA is disabled. Petitboot builds of Vikings do not have drivers for most discrete graphics processors, so there is no boot screen on which to select boot media, for example. Your display should start working as soon as Linux from an installed drive has been loaded.
A workaround for this is to enable the VGA jumper and connect a screen to the on-board VGA output because Petitboot has the required drivers for the on-board GPU (Aspeed AST2050) included. This is useful when installing a new operating system for example. The jumper settings can be reverted afterwards.
EHCI Debug Console
The EHCI debug console causes severe USB problems under both Libreboot and coreboot. This typically manifests as very slow boot / slow typing on USB keyboards. This issue appears to extend to the KCMA-D8 and KFSN4-DRE boards as well.
MMIO Resources Limit
The coreboot 32bit MMIO space limits the use of large amounts of PCI-e devices, such as more than a few network interfaces or graphics cards with the limit coming up sooner for older multi-port NIC's that have a switched design (ex: 82576), vs the newer style native multi-port pci-e setup (i350)
This is the reason for the "Not enough MMIO resources for SR-IOV" error when you attempt to enable SR-IOV on a system with both a quad port NIC and the onboard interfaces.
PIKE 2008 Libreboot Issues
Libreboot 20160818, 20160902 and 20160907 all have a bug: in SeaBIOS, PCI options ROMs are loaded when available, by default. Technically speaking this isn't a problem, because an option ROM can be free or non-free. Loading the option ROM from the PIKE2008 module on the KGPE-D16 causes the system to hang at boot. It's possible to use this in the payload (if you use Linux as payload, or the Petitboot bootloader), or to boot (with SeaGRUB and/or SeaBIOS) from regular SATA and then use it in GNU/Linux. Linux is capable of using the PIKE2008 module without loading the option ROM.
Libreboot-unstable (or Libreboot git master) now disables loading PCI option ROMs, but previous releases with SeaGRUB (20160818-20160907) do not. You can work around this by running the following command:
$ ./cbfstool yourrom.rom add-int -i 0 -n etc/pci-optionrom-exec
You can find cbfstool in the Libreboot util archive with the libreboot release that you are using.
The 4 total PCI-e slots may be limiting, but as the board has PCI-e ACS you may be able to use an external ACS supporting PCI-e expansion system - you would still have IOMMU security and performance as ACS support means that the devices beyond the external switch will be placed in separate IOMMU groups and thus you will maintain security and not have to use the unsafe attachment override for attaching devices to virtual machines.
NOTE: MMIO space limit dependent.
MCM/NUMA notes - Read if you play video games
NOTE: All G34 CPU's are dual-MCM thus with two NUMA nodes, if you play video games or need a single task with many threads the socket C32 single MCM/NUMA node KCMA-D8 with a 4386 might have improved performance although it is also possible to play games with a dual node CPU without stuttering.
The correct way to do this is to create a VM with properly pinned CPU's including iothread/emulator with all of the RAM on one node which is the same one that your interrupts for assigned devices such as graphics usb etc are being processed on.
Turbo Examples: If you have a 16 core CPU to obtain Turbo 2 you would select 2 modules and thus 4 cores from each MCM/NUMA node - then you allocate all of the hugepages/VM RAM on node 0 where the interrupts are assigned - this will provide the best gaming performance with a 16 core CPU. If you have dual 8 core 6328 CPU's the best VM gaming performance is gained by using both node zeros from both CPU's and hugepages RAM on the first node (zero) of the first CPU - this obtains 8 cores at 3.8ghz. You would also need to isolate the CPU's not in use by using the isolcpus kernel command line option and moving away interrupts if they somehow migrate to an isol'ed cpu.
Free Software Foundations "Respects Your Privacy" (RYF) certification
The Vikings D16 (a relabelled KGPE-D16) board is being sold with coreboot/Libreboot pre-installed. It is the first workstation/server mainboard that has been "RYF - Respects Your Freedom" certified by the Free Software Foundation on March 6th, 2017.