I just bought this Epyc Cpu equivalent to a Epyc 9775. AMD EPYC 9B45 Series 128-Cores 2.7GHz base clock, boost to3.7GHz SP5 512MB 500W | eBay
New to server cpu, I want to know which motherboard to get for a single slot SP5 or dual if possible because I only bought one cpu, and best ram kit, anything I need to know before hand! Thank you!
Never buy a dual-socket Motherboard unless you need the additional PCIe lanes or memory capacity that the second socket provides. The PCIe slots are distributed across the two sockets in a dual-socket system. If you only install one CPU, you can only use half of them.
I have 2 options right here which one is a better choice:
It all depends on what you want to do, the two boards are quite different in their functional design.
I usually go with Supermicro and have only had one Tyan board so far, but that was 15 years ago, no idea if the current boards are any good
Your CPU has 12 memory channels, get something like this, but look for revision 2.x
Some things to keep in mind:
Memory configuration.
SP5 Epycs, beside a few semi-custom SKUs (9D64), have 12-channel memory controllers. SP5 motherboards however can come in a variety of configurations, most commonly 8-/12-/24-DIMM.
Unless you know exactly what you want, you should avoid 8- and 24-DIMM boards. 8-DIMM boards mean you give up 1/3 of your processor’s potential memory bandwidth. 24-DIMM boards may seem attractive, but keep in mind that 2DIMM/ch SP5 boards take a hit on memory frequency, even if you only populate 1DIMM/ch. Read the motherboards spec sheet for details.
Power delivery.
Not all SP5 boards are born equal. Previous gen boards predating Zen5 can only support 400W TDP CPUs. Newer boards designed with Zen5 in mind can support the full 500W. I’m not sure what would happen if you put a 500W CPU in a 400W board, presumably the board would set the cTDP to 400W. Again, motherboard spec sheet will have that detail.
Supermicro.
Supermicro H13 generation boards are in a weird situation when it comes to Epyc 9005. The spec sheet reads “AMD EPYC™ 9005 series drop-in support requires board revision 2.x”, which sounds like rev 1.x boards can support Epyc 9005 with a BIOS update. But BIOS update page reads “For AMD EPYC™ 9005 Series Processor support, please ensure your motherboard revision is R2.0 or higher.”
It’s unclear whether rev 1.x boards support Epyc 9005 at all. I hope someone can clear this up, but if you do decide on one, make sure that you’re getting a rev 2.x.
DP boards.
AMD Epyc is not Intel Xeon, they do IO differently.
Xeon’s inter-socket UPI links are statically configured, meaning that a Xeon will always have a certain amount of PCIe lanes available, regardless of what configuration you run it with.
Epyc’s inter-socket xGMI links are field configurable. An Epyc has 4 G-link groups (G for xGMI) and 4 P-link groups (P for peripheral), each x16 wide, for a total of 128 lanes.
On a SP boards, you can use all 128 lanes as PCIe.
On a “regular” DP board, all 4 G-link groups will be repurposed as xGMI links, leaving the processor with 4x16 P-link groups for peripherals. Which totals 128 PCIe lanes per system.
There’s also an IO-intensive 3 link DP configuration, which gives you 160 lanes per system. But you only see the benefits of such a configuration on one of those GPU racks with a proprietary motherboard form-factor.
So unless you need that extra compute, don’t bother with DP boards.
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And a couple of tips that are not SP5-specific.
Board layout.
This one is fairly obvious. A memory slot, even if unpopulated, will physically interfere with a PCIe add-on card. Some motherboards put PCIe slots behind memory slots (e.g. Gigabyte MZ33-AR1), those PCIe slots will not accept full-length add-on cards. Important if you want to build a GPU system.
Firmware.
Firmware quality can vary wildly between different OEMs. This will be important if you want certain features like NVMe hot-swap.
I haven’t had enough experience with these OEMs to give you a conclusive recommendation, but ASRock Rack is notorious for their firmware support policy. They rarely (if ever) patch vulnerabilities and update microcode. You usually only get firmware updates when a new processor generation comes out.
Fans.
This is a weird one, but you should avoid PWM fans with low minimum RPMs. Fans dropping below a certain RPM will trigger a BMC panic, ramping the fans up to max before dropping back down. This cycle will repeat frequently, very annoying if your system is expected to be around people.
what board do you suggest for SP5 with 12 dimms, 500W Cpu, and no interference with pcie slot? I struggle to find one with all that options.
The perfect SP5 motherboard doesn’t exist. You’ll have to decide what your priorities are, and weigh each option against your needs.
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ATX/SSI-CEB options:
Supermicro H13SSL
ATX / 400W / 12-DIMM@6000 / ??
This generic looking motherboard should be your starting point. It does everything fairly well, but there are usually better options if you want to prioritize one particular use case.
See my previous post for details on Epyc 9005 compatibility.
Tyan S8050
CEB / 400W / 8-DIMM@6000 / 9005
This one looks a lot like Supermicro’s H13SSL, but has an 8-DIMM memory configuration. Unless you are short on your budget, this one should be avoided.
Advantech ASMB-831
ATX / 210W / 6-DIMM@4800* / NA
I don’t know why this board even exists.
Lacks Epyc 9005 enablement.
ASUS K14PA-U12
ATX / 400W / 12-DIMM@4800* / NA
This is the first specialized board on this list. Has 8 MCIO-8I ports for NVMe storage, plus an onboard 2x 25GbE NIC.
Lacks Epyc 9005 enablement.
ASRock Rack TURIND8UD/GENOAD8UD
M-ATX / 400W / 8-DIMM@6400 / 9005
This 10.4"*10.5" board is one of those boards that ASRock Rack makes for their own amusement.
ASRock Rack TURIND8QM3/GENOAD8QM3
ATX / 400W / 8-DIMM@6400 / 9005
This board shouldn’t even be in this category. It has an OCP 3.0 slot where PCIe slots should go. It probably fits a standard case, but your IO will be rather limited.
ASRock Rack TURIND8/BERGAMOD8
ATX / 400W / 8-DIMM@6400or4800* / ??
This is a fairly standard ATX board. Trades 4 DIMM slots for some extra PCIe slots.
BERGAMOD8 lacks Epyc 9005 enablement, but will likely get it in the near future.
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E-ATX/SSE-EEB options:
Gigabyte MZ33 family
SSI-EEB
-AR0 400W / 24-DIMM@4800-4000-3600 / 9005
-AR1 500W / 24-DIMM@5200-4400-4000 / 9005
-CP0 400W / 16-DIMM@4800-4000-3600 / 9005
-CP1 500W / 12-DIMM@6400 / 9005
This family of boards have impressive IO, and contains AFAIK the only standard form-factor boards with 500W capabilities. The two bottom slots on -CP support full length cards, so you can run a single full-sized GPU on this board.
ASRock Rack GENOAD8X
SSI-EEB / 400W / 8-DIMM@4800 / 9005
A workstation board with more PCIe slots than you’d ever need. Gives up 4 DIMM slots for this capability, and surprisingly only supports 4800MT/s.
Epyc 9005 enablement in Beta firmware.
GENOAD24QM32/GENOAD24QM3
SSI-EEB/ 400W / 24-DIMM@5200-4400-4000 / 9005
A larger version of the TURIND8QM3, this one has an extensive array of MCIO-8I slots for storage.
I like MZ33-CP1, but what is the empty space on the board for? u2 storage? also why the m2 slot doesn’t support pcie 4 x4 but only gen 3 x4 such disappointing. I already bought Tyan S8050GM4NE-2T from amazon because of prime free return, might do MZ33-AR1. Since Supermicro H13SSL doesnt have enough pcie slot clearance for first slot, and a lot of boards dont have native 9005 supported.
So here are my top choices:
Should I return 2 and get 1?
If by empty space you meant the cut out near the rear IO, that’s an OCP 3.0 slot. Usually you’d fit a network adapter in there.
That 3.0x4 M.2 comes from a WAFL link. Besides the 128 PCIe 5.0 lanes, an SP5 Epyc also has 3.0x8 lanes (referred to as WAFL for some reason) for basic onboard IO: usually BMC and management NIC. You can use the M.2 for a simple boot drive.
MZ33-CP1 has already used up EVERY high speed link group available. 3 groups go to the 6 MCIO-8I ports (each can run x8 PCIe, you’d use them for NVMe drive back plane). 4 groups go to PCIe slots, and 1 group go to the OCP 3.0 slot (x16, NIC). Besides the bottommost slot being rated for 4.0 (I assume due to signal integrity issues), this is the absolute maximum amount of IO an SP5 Epyc can do.
MZ33-AR1 is a 24-DIMM board, and can’t support full length add-on cards. Your Epyc 9005 can do 6400MT/s with a decent 12-DIMM board, but on MZ33-AR1 it will only do 5200MT/s.
$1k for S8050 is insane. It’s available on Newegg for ~$600.
H13SSL doesn’t have PCIe/memory interference issues AFAIK, you can install full length cards on any of the x16 PCIe slots.
This motherboard has clearance issue between the ram module and the first pcie slot, unless u have a Ada 4500 SFF. Yes, it will fit. But I’m talking about 3090, 4090, 5090 they are not gonna fit in that first slot with the ram module installed. And is it supported 9005, from all the boards u mentioned. Its also one of the boards almost filled all my needs. Thank you so much your time again!
Ah… Didn’t think of consumer GPUs and their back plate, I thought you had data center GPUs in mind.
Finding the right SP5 board really is painful. The old ATX/SSI specification isn’t fit for purpose any more. It’s well past time the industry reexamine and update these specifications. Allegedly next gen server platforms will have 16-ch/socket variants. Without a new specification, it will probably be the end of homebuilt high-end servers.
Okay so I just finished my build with SuperMicro H13SSL-N Rev 2.0 and Epyc 9b45 with 1 stick of ram and I couldn’t get it to boot with my gtx 1080ti. U got any ideas?
check your manual and use DIMM Slot A1 and maybe set the PCIe Slot for the 1080 to PCIe3
edit:
Your EPYC 9B45 is a real special edition, is it definitely unlocked?
Check your System Event Log via IPMI if not done already
I’m having trouble connecting it using IPMI, can you help me with that? Thank you.
Connect the IPMI network port to a switch and look in the LOG of your DHCP server to see which IP has been assigned.
If you don’t have DHCP, go to the UEFI and set the IP address there.
Use your browser to connect to the address, username is admin or ADMIN and on your mainboard next to the CPU socket is a sticker with the password
Edit: Very important! Did you install the CPU exactly according to the instructions?
Yes, I used the Threadripper tool to tighten it to the click
if something is not working with the IPMI access, sometimes it is better to set a new user and ip address with ipmitool
edit: well forget that, that works only when your system is running 
it would also help, to remove the 1080 and connect a VGA monitor, if you still have one
I just took a look at my server with the Supermicro H12SSL-i, and it looks exactly like yours. The LED is green and everything is working.
Is it possible that you’re just not getting a signal from your 1080?
My system doesn’t beep during initialization, and I only know it’s running because the fans are spinning and the LED is green.
I have all fans running, no beep, blinking green led on the left, solid green on bottom of the board. I tried with another gpu and still no output on pcie slot 1 or 3, been trying to connect it with ipmi and got no luck. I will find a VGA monitor now.
yes I think your board and CPU is Ok, the VGA will show it
In the UEFI you will find settings to fix your GPU problem
BMC Heartbeat LED (LEDBMC)
A BMC Heartbeat LED is located at LEDBMC on the motherboard. When LEDBMC is blinking,
the BMC is functioning normally. See the table below for more informationOnboard Power OK LED (LED9)
LED9 is an onboard power OK LED. When this LED9 is lit, it means the system is turned
on, and all the system power rails are ready. When the system is turned off, or any one of
the system power rails fail, this LED will turn off. Turn off the system, and unplug the power
cable before removing or installing any component(s)
