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SUPERCOMPUTERS
Skip to the 91 checks

The packageWhat arrives on the invoice is one part number.

The layersWhat decides whether it works is everything inside it.

The silicon91 checks run over that detail before we quote.

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Everything we check before we quote

91 checks across eight areas. A blocking check means we will not quote the configuration as it stands, because it will not work. A warning means it will work but you should know about it, and you may well have good reason. Notes and suggestions are there so nothing about the machine surprises you after it arrives.

Try it on a configuration

Processor and board

Does the processor fit the board, and does the board fit the case. Simple in theory, and still the most common thing people get wrong on machines with more than one processor.

Socket mismatch

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The processor and board are different sockets. The chip will not seat.

More processors than sockets

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Quantity exceeds what the board physically has.

Mixed processor models

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Multi-socket systems need identical stepping, core count and TDP. Mismatched CPUs halt at POST.

Part is single-socket only

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The P-series parts are locked at the factory to refuse working in pairs, even though they look identical.

Second socket empty

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Half the DIMM slots and several PCIe slots are wired to CPU2 and will not function.

Board will not mount

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The chassis has standoffs for other form factors.

Tower or open frame in a rack deployment

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No rails, no ears, no enclosed airflow path. It cannot go in a cabinet.

Rack chassis chosen for a desk

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40mm fans at high static pressure are 60 dBA and up under load, exhausting into whoever sits behind.

Rack node without out-of-band management

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Every failed boot becomes a site visit.

Cooling

Whether the cooler can actually shift the heat the processor makes when it is working hard, rather than the number printed on the box.

No cooler

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None of the selected processors ships with a heatsink.

Fewer coolers than sockets

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Every populated socket needs its own.

No mounting for this socket

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Server sockets in particular have almost no aftermarket bracket options.

Cooler undersized

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Rated below the processor's sustained peak. Escalates from warning to blocking past 25% short.

Too tall for the chassis

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The panel or lid will not close.

Radiator will not mount

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Larger than the chassis accepts.

Passive heatsink in a chassis without forced airflow

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Rack heatsinks have no fan and do nothing in a tower.

Memory

The right type, in the right slots, in the right quantity. Filling the slots unevenly is the one that quietly costs you a third of your memory speed and gives no warning.

DDR4 module in a DDR5 board or vice versa

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Different keying, it cannot be inserted.

Board does not accept this module type

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Registered memory will not train on a consumer controller, and unbuffered will not initialise on a server one.

More modules than slots

Above the board's qualified ceiling

Above the processor's addressable ceiling

Processor memory controller is the limit

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The modules are rated faster than this processor will clock them. Not a fault, but you are paying for speed the machine cannot use.

Uneven channel population

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The controller falls back to a slower interleave. On a 12-channel EPYC, eight modules costs roughly a third of memory bandwidth.

ECC modules in a board without ECC support

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They run, but correction stays off and single-bit errors pass silently.

Processor does not support ECC

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Intel restricts ECC to Xeon and W-series.

Tall modules under a wide air cooler

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Anything over about 40mm fouls the cooler's front fan.

Modules will clock down

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You are paying for speed the platform cannot use.

Accelerators

Will the card physically go in, will it get air, and will it actually run at full speed once it is in there.

SXM or OAM module in a parts build

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These mount to a vendor baseboard sold as a complete system. There is no PCIe edge connector.

Card longer than the chassis clearance

Passive card without chassis airflow

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Datacenter accelerators have no fans and throttle within a minute in a tower.

More accelerators than the chassis supports

Not enough rear slot positions

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Triple-slot coolers consume neighbouring positions even though they use one PCIe connector.

More cards than x16 slots

A card will land in an electrically narrow slot

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It works, but host bandwidth is halved. Visible in multi-GPU training, not in gaming.

Lane budget oversubscribed

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GPUs, network and NVMe together exceed what the processor provides.

Mixed accelerator models

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Data-parallel training runs at the pace of the slowest card and is bounded by its VRAM.

Card negotiates down a PCIe generation

Odd number of NVLink-capable cards

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Bridges pair cards two at a time; one ends up unbridged.

NVLink unused with a single card

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A second identical card and a bridge gives one pooled memory space.

Storage

Which drives the bays in your case will take. Some drive types fit one way round but not the other, which catches people out.

Drive type the backplane cannot speak

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U.3 backplanes accept U.2, SATA and SAS. U.2 backplanes accept U.2 only, the connector mates but a U.3 drive will not enumerate.

More enterprise drives than bays

More M.2 drives than slots

More SATA devices than ports

Consumer NVMe in a server build

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Without power-loss protection an outage can lose already-acknowledged writes.

110mm M.2 module

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30mm longer than 2280. Many desktop boards have no standoff for it.

Hot-swap drives without a chassis

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U.2, U.3 and EDSFF drives need a backplane. The bay count cannot be checked until the chassis is chosen.

QLC in a training build

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Right for the read-heavy dataset tier, wrong for checkpoints and scratch.

Power

Enough power for the worst moment, not the average, and the right cables to deliver it. Adapters are where most burnt connectors start.

No supply in the build

Capacity below peak draw

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The unit shuts down under load, usually mid-job.

Not enough native 12VHPWR leads

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Running a 450W-plus card off a four-way 8-pin adapter is the most common cause of melted connectors.

Not enough PCIe cables

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Daisy-chaining two GPU connectors onto one cable exceeds its 150W rating.

Not enough EPS connectors for the board

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An empty header causes shutdowns under all-core load, it passes a quick test and fails a real job.

Supply will not mount in the chassis

Requires more than 230V

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Pakistani single-phase mains is 230V/50Hz.

Under 20% headroom

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Running near the ceiling shortens life, maxes the fan and leaves nothing for expansion.

ATX 2.4 supply feeding a 12VHPWR card

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Pre-3.0 units trip their over-current protection on the transients these cards produce.

Single non-redundant supply in a rack build

Over a single 230V circuit's continuous rating

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A 16A Pakistani domestic circuit is 3.68kW; continuous load should stay under about 2.9kW.

Accelerator uses a CPU-style power lead

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Keyed differently from PCIe 8-pin. Plugging a PCIe cable in damages the card.

Requires 200-240V

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Suits Pakistani mains; will not start on 110V.

Fabric

The network cards, the switch and the cables between them all have to agree. Two of those three can disagree without telling you anything is wrong.

InfiniBand-only adapters with an Ethernet switch

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The cable is identical and the connectors mate, but the protocols are unrelated.

Ethernet-only adapters with an InfiniBand switch

Cable does not fit any adapter

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Cage sizes are not interchangeable.

Cable does not fit the switch

No slot wide enough

Full-height card in a 1U chassis

Cable coded for a different vendor

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Most switches read the module EEPROM and refuse to bring the port up. Electrically fine, firmware says no.

Adapter cannot reach line rate on this board

Adapters and switch with no cabling

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Ports ship empty; optics are a meaningful share of the fabric budget.

VPI adapters will run in Ethernet mode

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You keep RoCE and GPUDirect, you lose in-network reduction.

Multi-GPU node without a GPUDirect adapter

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Every gradient exchange bounces through host memory.

Facility

The things outside the machine: will it fit the rack, can the rack get air, is there enough power on the circuit, and what happens when the power goes out.

Equipment exceeds rack height

Chassis too deep

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You need roughly 150mm behind the equipment for cable bend radius and the vertical PDU.

Load exceeds distribution capacity

UPS smaller than the load

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An overloaded UPS drops to bypass, doing nothing at the moment it is needed.

Door perforation below 65% with GPU nodes

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The doors become the thermal restriction.

Over 8kW on single-phase

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Beyond about 7.4kW a single-phase 32A feed is exhausted.

Line-interactive UPS on a multi-GPU load

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Given local grid behaviour, double-conversion is the safer specification.

No UPS

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Load-shedding will otherwise cut a running job and risk the filesystem.

Rack equipment with no rack selected

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Depth, load and power distribution cannot be validated until there is a cabinet to put it in.

No power distribution in the build

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The rack needs the load delivered to it. Worth pricing before the quotation rather than after.

Physical layout

The check that is hardest to do on paper and easiest to get wrong: laying every part out to scale inside the actual case and seeing whether it all physically goes. This is what the 3D viewport in the configurator is drawing.

Part does not fit inside the chassis

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Laid out to scale it sits outside the shell — too long, too tall or too deep for the space available. The viewport draws it in red where it breaks out.

Two parts want the same space

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They overlap in the arrangement drawn. The layout shown is one sensible way to fit the parts in rather than the only one, so this may come down to which bay or slot each ends up in — but it is worth resolving before it is built.

The build as a whole

Checks that are about the configuration rather than any one part in it: what is still missing, and the two decisions that are defensible on a desk and not in a rack.

No chassis

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Nothing can be checked for fit, airflow or drive bays until there is a case to check it against.

No motherboard

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The board decides socket, memory type, slot count and form factor. Almost every other check depends on it.

No processor

No memory

No storage

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The machine will build and post. It will not boot an operating system.

Parts still to choose

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Says which, and which checks are being skipped until they are there. An empty slot is not an error while you are still building.

Non-ECC memory in a server build

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Fine on a workstation somebody is sitting at. On a machine running unattended for days, a silently flipped bit produces a result nobody can tell is wrong.

Tested-pull or Grade B parts in the build

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Names the lines and their grade, so a mixed-condition machine is a decision rather than a surprise on delivery.

What these checks cannot tell you

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They tell you the machine will go together, switch on, and not cook itself or trip a breaker. They cannot tell you it is the right machine for your work. Four small graphics cards and one big one both pass every check on this page, but only one of them will hold the model you are trying to train. That is what the conversation about your quote is for.