SMI300XS Sample Questions Answers

Thecorrect order for removing trays before midplane removalis:

Disengage the PCIe tray first

This tray must be removed first becauseit provides access to the underlying system components.

Remove the GPU tray

TheGPU tray sits between the PCIe and motherboard traysand must be disengaged after PCIe components are cleared.

Remove the motherboard tray last

The motherboard tray isthe final component before midplane removal.

Removing it lastensures full accessto the system componentswithout obstructing critical connections.

Why other options are incorrect?

B (Motherboard before GPU tray)→ The motherboard tray must be removedlastto avoid disconnecting system-critical connections too early.

C (Motherboard tray first)→ Removing the motherboard firstrisks damagingPCIe and GPU components.

D (GPU tray first)→ TheGPU tray is dependent on the PCIe tray being removed first, making this order incorrect.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 System Removal Guideoutlines the correct order fortray disengagement before midplane removal.

TheAOM (Add-On Module) bracketis used to mount optional components like:

RAID controllers

Additional networking interfaces

BMC/IPMI modules

In theexample system shown in the video, theright AOM bracket does not contain an AOM card. This is because:

Supermicro’s default system configurations do not always ship with optional AOM cards.

Theleft AOM bracketusually housesoptional RAID or networking expansions, but theright bracket remains unoccupiedunless a specific expansion module is installed.

Official Documentation Reference:

SupermicroHardware Deployment Guideconfirms that theright AOM bracket is optionalandnot pre-installedin base configurations.

Components Located on Top of the Motherboard in Supermicro MI300X Systems

Fans and Fan Shrouds (Option A)

These are installedabove the motherboardtodirect airflow over the components.

Fan shrouds help focus airflow, ensuringefficient cooling of CPUs and GPUs.

Support Bar and AOM Brackets (Option B)

Thesupport bar reinforces the motherboard tray, preventing flexing.

AOM bracketshold optionalnetworking or RAID expansion modules.

Heatsinks and CPUs (Option C)

Large heatsinks are mounted on top of the CPUsto dissipate heat.

These ensureoptimal thermal managementof high-performanceAMD MI300X GPUs and processors.

Why Option D (DIMM Modules) is Incorrect?

❌DIMM modules (memory sticks) are installed in slots beside the CPU, but they arenot physically above the motherboardin a way that they could be considered a top-mounted component.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 System Overviewconfirms thatfans, heatsinks, AOM brackets, and support bars are mounted on top of the motherboard.

Why Must PSUs Be Removed Before Midplane Removal? (Option A)

Power must be fully disconnectedbefore handling the midplane to avoidelectrical damage.

Themidplane is directly linked to the power distribution system, and removing it while PSUs are still connected can cause:

Short circuits

Residual electrical charge damage

Connector arcing and failure

Why Must PCIe, Motherboard, and GPU Trays Be Disengaged? (Option C)

These traysobstruct access to the midplane, meaning they must bedisengaged firstbefore midplane removal.

While they do not need to becompletely removed, they must beloosened and moved slightlyto allow for safe midplane extraction.

Why Other Options Are Incorrect?

B (Remove MCIO cables)→MCIO cables should be disengaged, but full removal is not requiredbefore midplane removal.

D (Remove fans and fan shutters)→ Fan assemblies are separate from the midplane anddo not need to be removedduring this step.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Disassembly Manualexplicitly states thatremoving PSUs and disengaging trays are necessary steps before midplane removal.

When reinstalling theNVMe backplane, several critical cables must be properlyreconnectedto ensure the system functions correctly.

Required Connections:

SATA Cable→ Some NVMe backplanesalso support SATA drives, requiring SATA connectivity.

Power Cables→ The NVMe backplanerequires direct powerto enable SSD operations.

MCIO Cables→ These cables providehigh-speed data connectivitybetween the NVMe drives and the motherboard.

54-Volt Power Cable→ Thissupplies direct powerto the NVMe backplane foroptimal performance and stability.

Why other options are incorrect?

B (Only SATA cable)→ NVMe backplanes usePCIe-based storage. While SATA connectionsmayexist,they are not the only required cables.

C (Only MCIO cables)→ While MCIO cables are necessary for PCIe-based NVMe drives,power cables must also be reconnectedfor the system to function.

D (Only power cables)→Data communication would failwithout MCIO connections, rendering the systemunable to detect NVMe drives.

Official Documentation Reference:

Supermicro NVMe Service GuideandAS-8125GS-TNMR2 Installation Manualemphasize thecorrect reinstallation of power and data cablesto avoidhardware malfunctions.

Importance of Mapping Cables Before Disconnection

TheNVMe backplaneinSupermicro MI300X systemsuseshigh-speed PCIe lanesandpower distribution linesthat must beproperly mapped before disconnection.

Why Should Cables Be Mapped?

Prevents misconnection during reassembly

The system usesmultiple identical-looking cables(MCIO, NVMe, and power cables).

Misplacing a cable in the wrong portcan causeboot failures, drive detection issues, and system instability.

Reduces downtime for troubleshooting

Without a mapped diagram or a picture, technicians may spendhours debugging misconnected cables, leading todelays in system restoration.

Ensures proper airflow and cable management

Incorrectly routed cablescanblock airflow, leading tooverheating and thermal throttling of GPUs or storage devices.

Correct Process for Cable Mapping

Take high-resolution picturesbefore disconnecting cables.

Label each cable and its corresponding portusing numbered stickers or colored tags.

Create a simple mapping diagramshowing which cable connects to which port.

Double-check the mapping before removal.

Why Other Options Are Incorrect?

B (Disconnect the power supply first)→ While powering down is important,mapping cables is the primary precaution before disconnection.

C (Randomly disconnect cables)→ Leads to confusion and potential system failures due to incorrect reconnections.

D (Shake the system to loosen cables)→NEVER shake a server, as this can damage internal components and misalign connectors.

Official Documentation Reference:

Supermicro NVMe Installation Guidestates thatproper cable mapping is required before NVMe backplane disconnectionto avoid misplacement.

Before removing theNVMe backplanein aSupermicro MI300X GPU system,all NVMe drives must be disengaged but not fully removed.

Why is this necessary?

Ensures safe backplane removal

NVMe drives are directly connected to the backplane viaMCIO or U.2 connectors.

Keeping them engaged couldput stress on the connectors, causing damage.

Prevents accidental disconnects

Removing the drives completely isnot necessary, butdisengaging them ensures they do not obstruct removal.

Avoids power damage

If the drives remain engaged during backplane removal, they may still haveresidual power, which can causeconnector damage or electrical failure.

Why other options are incorrect?

B (Disengage PSUs)→ While power should be off,removing PSUs is not required for NVMe backplane removal.

C (Disengage fans)→ Fans are independent components anddo not interfere with the NVMe backplane.

D (Disengage the field engineer)→ Not a valid answer; field engineers are not system components.

Official Documentation Reference:

Supermicro NVMe Storage Disassembly Guiderecommendsdisengaging NVMe drives but not fully removing thembefore backplane removal.

Themidplane bracket in Supermicro MI300X GPU systemsis secured with6 screwsthat must beremoved before disassembly.

Why 6 screws?

3 screws on each side of the chassishold the midplane bracket in place.

This design helps stabilize the midplaneand prevents movement.

Failure to remove all 6 screws can result in forcefully damaging the bracket.

Official Documentation Reference:

Supermicro AS-8125GS-TNMR2 Disassembly Manualspecifies that6 screws must be removed before handling the midplane bracket.

ForSupermicro MI300X GPU systems,removing the power supply unit (PSU) improperlycan lead to serious issues.

Why the red lock exists?

Thered locking mechanismensures that thePSU is properly securedin the system.

Before disengaging the PSU, thered lock must first be unlockedto avoid damage.

If you forcefully shift the release lever without unlocking the red lock:

B: The power supply unit will fail→ If the PSU is removed improperly, it can causeinternal damageto power connectors, resulting in PSUfailure or improper functioning.

C: You could permanently damage the lock on the power supply unit→ Thelocking mechanismis designed for smooth disengagement. Forcefully shifting the lever canbreak or warpthe lock, making itimpossible to secure the PSU back in place.

Incorrect Answers Explained:

A (All answers are correct)→ This is incorrect becausenot all answers are valid.

D (The PSU can no longer be secured into the tray)→ This happensonly if the lock is damaged, which is covered underoption C.

Supermicro’s official documentation clearly statesthatunlocking the red lock firstis a critical step before removing or replacing the PSU.