What RigSync Checks Before You Buy

What RigSync Checks Before You Buy

Most compatibility checkers answer one question: do the sockets match? That's the right starting point — it's not the complete picture.

RigSync runs two separate layers of checks on every build in the Component Browser. The first layer is compatibility — things that prevent a build from working or working well. The second layer is topology — things that affect how well components communicate electrically, which only becomes visible when you look at lane assignments, bandwidth, and slot sharing together.

Here's exactly what both layers check.

Compatibility Checks

These run automatically as you add components in any builder path. Errors block problematic combinations; warnings flag things that work but not optimally.

Core Compatibility

Socket and chipset — The CPU socket must match the motherboard socket. Beyond that, RigSync enforces chipset compatibility explicitly for platforms where it matters — Threadripper Non-Pro and Pro CPUs require different chipsets (TRX50 vs WRX90), and that distinction is checked separately from socket match.

Memory type — Memory type (DDR4 vs DDR5) is checked against both the CPU and the motherboard independently.

Case form factor — The motherboard form factor (ATX, mATX, ITX) must be supported by the selected case.

BIOS update requirement — For newer CPUs on older motherboard revisions, RigSync flags if the board may require a BIOS update before the CPU will POST.

Physical Fit

GPU length — Compared against the case's maximum GPU clearance. A warning fires at 95% of the limit; an error fires if the GPU is too long to fit.

PSU length and form factor — PSU length is compared against case clearance. Cases that require SFX form factor get an error if an ATX PSU is selected.

CPU cooler height — Estimated or measured cooler height is compared against case clearance. Cases under 150mm clearance get an additional warning regardless of the cooler selected.

AIO radiator length — For liquid coolers, the radiator size is checked against the case's maximum radiator support.

PCIe slot physical fit — Multi-GPU and expansion card configurations run a placement simulation that checks whether cards fit given their physical slot widths — not just whether an electrical slot is available on paper.

Board edge extension — When a GPU or expansion card is assigned to a slot where its physical body extends past the last slot on the board, RigSync flags it by name with the specific slot the card landed in. This matters most on boards where a wide GPU ends up in a lower slot after a second card claims the primary one. The check runs from the slot placement simulation and fires before you look at the topology panel.

Power

Wattage — Estimated system power draw is calculated from all selected components. If PSU wattage falls below the estimate, an error fires.

GPU power connector compatibility — The PSU's available power connectors are checked against what the GPU requires. A PSU that's sufficient in wattage but missing the right connectors gets a separate error.

PSU efficiency recommendation — High-tier builds get an advisory if the PSU efficiency rating doesn't match the component tier.

Storage

M.2 slot type — M.2 drives are matched against available M.2 slot form factors (2230, 2242, 2260, 2280, 22110). A drive that doesn't fit the board's slots gets an error before you buy.

SATA port availability — SATA drives verify the motherboard has SATA ports available.

Multi-drive slot count — Adding multiple M.2 drives checks total slot availability and verifies all form factors are supported simultaneously.

NVMe generation — NVMe drives are checked against the motherboard's M.2 PCIe generation. A Gen 5 drive on a board that only supports Gen 3 gets an info note on the speed reduction.

Memory

Capacity limits — Total memory capacity is checked against both the CPU maximum and the motherboard maximum.

ECC compatibility — Workstation CPUs that support ECC flag a recommendation when non-ECC memory is selected. Non-ECC platforms flag registered or ECC memory (the system won't POST).

Registered/buffered memory — RDIMM and LRDIMM memory is blocked on consumer platforms that require UDIMM. This is a hard error.

Speed compatibility — Memory speed is checked against the motherboard's native supported speeds and the CPU's maximum. When XMP/EXPO is needed to reach rated speed, the warning explains which profile to enable and what the fallback JEDEC speed will be.

Multi-kit warnings — Builds with multiple memory kits get additional checks: speed mismatch between kits, CAS latency mismatch, and whether the kits are identical or different product lines. Each scenario produces a specific warning with the actual impact (all modules running at the slowest speed, for example).

Channel optimization — Dual-channel and quad-channel platforms flag when the module count won't fill the available memory channels, with the expected bandwidth impact noted.

Performance

CPU/GPU balance — Normalized performance scores for CPU and GPU are compared. Three severity levels apply depending on the ratio: moderate (info), significant (warning), or severe (warning). For AI-generated builds, the optimizer intentionally targets GPU performance, so GPU bottleneck warnings are suppressed there.

PCIe version mismatch — GPU and CPU PCIe generation compatibility is checked. High-end GPUs get a bandwidth impact estimate. Budget and mid-range GPUs get a note that the performance impact is negligible. The motherboard is only mentioned when it's the actual bottleneck.

Connectivity

Monitor port compatibility — The monitor's input connections are checked against outputs available from the GPU, CPU integrated graphics, and motherboard video outputs.

Graphics output availability — If no GPU is selected and the CPU has no integrated graphics, an error fires to prevent a build with no display output.

CPU cooler socket compatibility — The cooler's supported socket list is checked against the CPU socket.

Front panel USB-C — If the case has a front panel USB-C port, the motherboard is checked for a compatible internal USB-C header.

Topology Warnings

Topology warnings are a second layer that runs after basic compatibility. These aren't about components that don't work — they're about components that work, but share electrical resources in ways that affect real-world bandwidth or slot availability.

The topology layer currently supports AM5, LGA1851, and sTR5 platforms. Support for additional platforms is in progress.

Physical Slot Blocking

Wide GPUs — 2.5-slot, 3-slot, 3.5-slot coolers — cover the slot openings physically below them on the board. The topology panel marks those slots as BLOCKED, distinct from DISABLED (which means a lane conflict). A blocked slot has its lanes fully available; the problem is purely physical — another card is sitting on top of it.

If a component is assigned to a blocked slot, the warning identifies what's blocking it and which card caused it. This is tracked separately from lane conflicts because the cause and the fix are different: a lane conflict is resolved by removing a device; a physical block is resolved by choosing a narrower card or a different slot arrangement.

No other PC building tool models card footprint on the board. Most assume that if a slot has electrical lanes, it's usable.

GPU PCIe Bandwidth

When a GPU runs at fewer lanes or a lower PCIe generation than it was designed for, the warning calculates actual bandwidth in GB/s and compares it against the GPU's optimal bandwidth. Severity is based on where the effective bandwidth lands:

• Above ~16 GB/s (PCIe 4.0 ×8): info — real-world impact under 3% for most workloads
• Between ~8–16 GB/s: info — most workloads unaffected; compute and high-framerate scenarios may see a 5–10% reduction
• Below ~8 GB/s: warning — measurable performance loss in GPU-intensive workloads

The warning identifies whether the CPU, the motherboard, or both are the limiting factor.

M.2 Downshift

Some CPUs reduce the PCIe generation available to specific M.2 slots below the board's native spec. When an NVMe drive is installed in an affected slot, the warning shows the effective speed versus the rated speed and notes that a CPU with full lane support would unlock the full throughput.

Some CPUs also restrict which M.2 form factors a slot accepts. Slots that accept all sizes under most CPUs may be limited to specific form factors with others — this fires as a warning when an incompatible drive is installed.

Slot Conflicts

PCIe and M.2 slots frequently share electrical lanes. Installing a component in one slot can disable or reduce another:

• Disabled — The slot's lanes are fully committed to another device. If a component is installed there, it gets a warning that it cannot operate. If the slot is empty, it gets an info note that it's unavailable while the other device is occupied.
• Downgraded — The slot still functions but at reduced lanes or generation due to lane sharing. The warning shows the native configuration, the effective configuration, and the throughput at the reduced level.
• SATA ports — Some PCIe expansion cards take SATA ports offline when occupied. This is tracked and surfaced the same way as PCIe conflicts.

Chipset Uplink Saturation

The chipset connects to the CPU through a fixed-bandwidth link called the DMI. When the combined theoretical throughput of all chipset-routed devices significantly exceeds the DMI bandwidth, a warning appears. Severity is based on the ratio: above 120% of DMI capacity triggers an info note; above 175% triggers a warning that simultaneous heavy I/O will cause throughput drops.

Bifurcation

NVMe expansion cards that support multiple M.2 drives without a PLX switch require the host PCIe slot to support bifurcation — splitting one physical connection into independent channels, one per drive. The check covers:

• Whether the slot supports the required bifurcation mode at all
• Whether it supports only a partial mode (some drives accessible, not all)
• Whether the mode requires a BIOS setting to be enabled first
• Whether the installed CPU family supports the bifurcation mode on that specific slot

Cards with a PLX switch chip handle lane splitting internally and don't require bifurcation from the motherboard — the system accounts for this automatically.

Expansion Card Bandwidth

Expansion cards running at reduced bandwidth get their own downshift warning separate from GPUs. For multi-slot NVMe adapters, the warning calculates per-slot bandwidth at the reduced lane count so the actual storage impact is clear, not just the raw percentage loss.

How the Two Layers Work Together

Compatibility checks are fast and definitive — a socket mismatch is a hard stop that fires immediately. Topology warnings require a complete build state: the motherboard's lane routing data, the installed components, and their assigned slots.

That's why the Component Browser has a topology panel alongside the compatibility tab. The panel shows lane assignments visually; the warnings translate those assignments into plain-language descriptions of the actual impact. Both update in real time as you add or change components.

The goal for both layers is the same: issues that would only surface after assembly should surface before you buy anything.

See both layers in the Component Browser →

New to PCIe topology? Understanding PCIe Topology Warnings covers the concepts in plain language.