Side by side

PCIe x8 versus x16 card-edge connectors

Is the card-edge form x8/98-position or x16/164-position? Mechanical form does not establish generation, lane wiring or platform support.

Computer-generated illustration, not a photograph. — P297 · ConnectorPCI Express x8 98-position card-edge connector

How they differ

PCI Express x8 98-position card-edge connector Confirm the PCIe x8 card-edge form and 98-position variant, then verify generation, lane wiring and device support from the host documentation.
PCI Express x16 164-position card-edge connector Confirm the x16 card-edge form and then verify motherboard/device documentation for generation, lane wiring, bifurcation and power behavior.

At a glance

Source-scoped form facts; counts, variants and unknowns are distinct
Field	PCI Express x8 98-position card-edge connector	PCI Express x16 164-position card-edge connector
Type	Connector	Connector
Family	Storage	Storage
Shape	card edge	card edge
Nominal contacts	98S338Source-backed nominal position/contact count for identification: 98. Not a pinout or manufacturing drawing.	164S281Source-backed nominal position/contact count: 164.
Positions / cavity span	98 (Claim C297A); 98 (Claim C297B)S338 · S357Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V50 identification fact only; no wiring, protocol compatibility, installation or fabrication approval is inferred. Mechanical/contact-count context only; no PCIe generation, lane enablement, logical pin assignment or board-layout approval is inferred.	164 (Claim C261A); 164 (Claim C261B)S281 · S324Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V43 catalogue-expansion identification fact only; not independent technical approval, fabrication data, wiring instruction, protocol guarantee or end-to-end compatibility proof. V48 product-level mechanical identifier only; no universal PCIe lane assignment, generation support or motherboard implementation is inferred.
Contact rows	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Connector role	card-edge; socketS338 · S357 · S338Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. PCI Express x8 card-edge connector example Named series only, not every family part: Amphenol PCI Express Gen3 98-position family. Documented role: socket. Family source explicitly mapsx1=36,x4=64,x8=98; no exactpart or connector size derived. Standalone retention mechanism varies by product.	card-edge; socket (10146067-113A0LF)S281 · S324 · S281Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. vertical PCI Express x16 card-edge connector example 10146067-113A0LF. Documented role: socket. 164positions; vertical solder-terminated connector.1.57mm PCB thickness excluded from connector geometry. Drawing web text lacks dimensions; direct403.
Key distinction	The x8 mechanical connector form does not establish PCIe generation, active lane width, bifurcation or platform support.	The x16 mechanical form does not by itself establish PCIe generation, active lane width, power budget or platform support.

Full evidence ledger and sources ↓

Illustrations are computer-generated with prior AI visual review; independent technical and rights review pending. A comparison is not a compatibility verdict.

This comparison stays within one evidence layer.

All selected records are Connector records. Similar layer does not mean compatible, interchangeable or safe to mate.

Families represented: Storage

Look here first

Spot the difference.

Read the views →

Not a size comparison. Illustrations fit the same display boxes; their physical dimensions are not shown to a common scale. No mating or compatibility verdict follows.

PCIe x8 (98-position) slot — top-facing keyed motherboard expansion slot schematic; no pinout or measured geometry; review pending

P297 / Top-facing conceptual slot opening

PCI Express x8 98-position card-edge connector

Motherboard-side receptacle / expansion slot

Visible clue: The slot extends beyond x4 in the long section after the key.

Still check: Source-supported family key and position-class recognition. Stylized channel; hatching is not the contact arrangement, and there are no real tolerances, pins or measured dimensions.

PCIe x16 (164-position) slot — top-facing keyed motherboard expansion slot schematic; no pinout or measured geometry; review pending

P261 / Top-facing conceptual slot opening

PCI Express x16 164-position card-edge connector

Motherboard-side receptacle / expansion slot

Visible clue: Longest of these four typical keyed expansion-slot formats.

Still check: Source-supported family key and position-class recognition. Stylized channel; hatching is not the contact arrangement, and there are no real tolerances, pins or measured dimensions.

The reference ledger

Read the same question across.

2 selected records · 14 fields
No score. No compatibility verdict.

On a narrow screen, scroll the table sideways or open the field-by-field reading view below. Illustrations are not a size comparison.

Comparison of selected field notes; source links accompany each documented specification
What you are comparing	P297 / ConnectorPCI Express x8 98-position card-edge connector Identification schematic · not to scale · drawing review pending	P261 / ConnectorPCI Express x16 164-position card-edge connector Identification schematic · not to scale · drawing review pending
Layer	Connector	Connector
Key distinction	The x8 mechanical connector form does not establish PCIe generation, active lane width, bifurcation or platform support.	The x16 mechanical form does not by itself establish PCIe generation, active lane width, power budget or platform support.
Nominal contacts	98S338Source-backed nominal position/contact count for identification: 98. Not a pinout or manufacturing drawing.	164S281Source-backed nominal position/contact count: 164.
Positions / cavity span	98 (Claim C297A); 98 (Claim C297B)S338 · S357Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V50 identification fact only; no wiring, protocol compatibility, installation or fabrication approval is inferred. Mechanical/contact-count context only; no PCIe generation, lane enablement, logical pin assignment or board-layout approval is inferred.	164 (Claim C261A); 164 (Claim C261B)S281 · S324Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V43 catalogue-expansion identification fact only; not independent technical approval, fabrication data, wiring instruction, protocol guarantee or end-to-end compatibility proof. V48 product-level mechanical identifier only; no universal PCIe lane assignment, generation support or motherboard implementation is inferred.
Populated contacts	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Contact rows	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Contact pitch	1 mm Contact pitch (Recorded example component); 1 mm Source-described pitch / centerline (Claim C297B); 1 mm centerlineS357 · S338Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. example_component; PCI Express x8 card-edge connector example Mechanical/contact-count context only; no PCIe generation, lane enablement, logical pin assignment or board-layout approval is inferred. Named series only, not every family part: Amphenol PCI Express Gen3 98-position family. Documented role: socket. Family source explicitly mapsx1=36,x4=64,x8=98; no exactpart or connector size derived. Standalone retention mechanism varies by product.	1 mm Contact pitch (Recorded example component); 1 mm Source-described pitch / centerline (Claim C261B); 1 mm centerline (10146067-113A0LF)S324 · S281Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. example_component; vertical PCI Express x16 card-edge connector example V48 product-level mechanical identifier only; no universal PCIe lane assignment, generation support or motherboard implementation is inferred. 10146067-113A0LF. Documented role: socket. 164positions; vertical solder-terminated connector.1.57mm PCB thickness excluded from connector geometry. Drawing web text lacks dimensions; direct403.
Dimensions / axis	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Connector role	card-edge; socketS338 · S357 · S338Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. PCI Express x8 card-edge connector example Named series only, not every family part: Amphenol PCI Express Gen3 98-position family. Documented role: socket. Family source explicitly mapsx1=36,x4=64,x8=98; no exactpart or connector size derived. Standalone retention mechanism varies by product.	card-edge; socket (10146067-113A0LF)S281 · S324 · S281Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. vertical PCI Express x16 card-edge connector example 10146067-113A0LF. Documented role: socket. 164positions; vertical solder-terminated connector.1.57mm PCB thickness excluded from connector geometry. Drawing web text lacks dimensions; direct403.
Coupling / latch	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Keying / polarization	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.	Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
Documented identification	Amphenol identifies the standard PCI Express x8 card-edge connector form with 98 positions/contacts in its PCIe connector range.C297A	164-position/contact recognition fact in the cited implementation.C261A
Physical size versus wired lanes	Not an equivalent field	AC-HES example: one physical x16 slot has x4 mode and a documented x1 population condition.C261C
Evidence	C297A → Independent review pending	C261A,C261C → Independent review pending

Read field by field — no sideways scrolling

The same selected records, fields, values and source links as the table. Missing fields remain non-equivalent; no values are merged.

Layer

PCI Express x8 98-position card-edge connectorP297 / Connector: Connector
PCI Express x16 164-position card-edge connectorP261 / Connector: Connector

Key distinction

PCI Express x8 98-position card-edge connectorP297 / Connector: The x8 mechanical connector form does not establish PCIe generation, active lane width, bifurcation or platform support.
PCI Express x16 164-position card-edge connectorP261 / Connector: The x16 mechanical form does not by itself establish PCIe generation, active lane width, power budget or platform support.

Nominal contacts

PCI Express x8 98-position card-edge connectorP297 / Connector: 98S338Source-backed nominal position/contact count for identification: 98. Not a pinout or manufacturing drawing.
PCI Express x16 164-position card-edge connectorP261 / Connector: 164S281Source-backed nominal position/contact count: 164.

Positions / cavity span

PCI Express x8 98-position card-edge connectorP297 / Connector: 98 (Claim C297A); 98 (Claim C297B)S338 · S357Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V50 identification fact only; no wiring, protocol compatibility, installation or fabrication approval is inferred. Mechanical/contact-count context only; no PCIe generation, lane enablement, logical pin assignment or board-layout approval is inferred.
PCI Express x16 164-position card-edge connectorP261 / Connector: 164 (Claim C261A); 164 (Claim C261B)S281 · S324Recorded source-scoped values; named examples do not describe every family variant or establish compatibility. V43 catalogue-expansion identification fact only; not independent technical approval, fabrication data, wiring instruction, protocol guarantee or end-to-end compatibility proof. V48 product-level mechanical identifier only; no universal PCIe lane assignment, generation support or motherboard implementation is inferred.

Populated contacts

PCI Express x8 98-position card-edge connectorP297 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
PCI Express x16 164-position card-edge connectorP261 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Contact rows

PCI Express x8 98-position card-edge connectorP297 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
PCI Express x16 164-position card-edge connectorP261 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Contact pitch

PCI Express x8 98-position card-edge connectorP297 / Connector: 1 mm Contact pitch (Recorded example component); 1 mm Source-described pitch / centerline (Claim C297B); 1 mm centerlineS357 · S338Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. example_component; PCI Express x8 card-edge connector example Mechanical/contact-count context only; no PCIe generation, lane enablement, logical pin assignment or board-layout approval is inferred. Named series only, not every family part: Amphenol PCI Express Gen3 98-position family. Documented role: socket. Family source explicitly mapsx1=36,x4=64,x8=98; no exactpart or connector size derived. Standalone retention mechanism varies by product.
PCI Express x16 164-position card-edge connectorP261 / Connector: 1 mm Contact pitch (Recorded example component); 1 mm Source-described pitch / centerline (Claim C261B); 1 mm centerline (10146067-113A0LF)S324 · S281Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. example_component; vertical PCI Express x16 card-edge connector example V48 product-level mechanical identifier only; no universal PCIe lane assignment, generation support or motherboard implementation is inferred. 10146067-113A0LF. Documented role: socket. 164positions; vertical solder-terminated connector.1.57mm PCB thickness excluded from connector geometry. Drawing web text lacks dimensions; direct403.

Dimensions / axis

PCI Express x8 98-position card-edge connectorP297 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
PCI Express x16 164-position card-edge connectorP261 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Connector role

PCI Express x8 98-position card-edge connectorP297 / Connector: card-edge; socketS338 · S357 · S338Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. PCI Express x8 card-edge connector example Named series only, not every family part: Amphenol PCI Express Gen3 98-position family. Documented role: socket. Family source explicitly mapsx1=36,x4=64,x8=98; no exactpart or connector size derived. Standalone retention mechanism varies by product.
PCI Express x16 164-position card-edge connectorP261 / Connector: card-edge; socket (10146067-113A0LF)S281 · S324 · S281Named source examples retain separate role, part, view and axis limits; values are not a universal family specification. vertical PCI Express x16 card-edge connector example 10146067-113A0LF. Documented role: socket. 164positions; vertical solder-terminated connector.1.57mm PCB thickness excluded from connector geometry. Drawing web text lacks dimensions; direct403.

Coupling / latch

PCI Express x8 98-position card-edge connectorP297 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
PCI Express x16 164-position card-edge connectorP261 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Keying / polarization

PCI Express x8 98-position card-edge connectorP297 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.
PCI Express x16 164-position card-edge connectorP261 / Connector: Not recordedNot recorded in a normalized source-scoped field. Consult the exact part/revision; no value inferred from illustrations.

Documented identification

PCI Express x8 98-position card-edge connectorP297 / Connector: Amphenol identifies the standard PCI Express x8 card-edge connector form with 98 positions/contacts in its PCIe connector range.C297A
PCI Express x16 164-position card-edge connectorP261 / Connector: 164-position/contact recognition fact in the cited implementation.C261A

Physical size versus wired lanes

PCI Express x8 98-position card-edge connectorP297 / Connector: Not an equivalent field
PCI Express x16 164-position card-edge connectorP261 / Connector: AC-HES example: one physical x16 slot has x4 mode and a documented x1 population condition.C261C

Evidence

PCI Express x8 98-position card-edge connectorP297 / Connector: C297A →
Independent review pending
PCI Express x16 164-position card-edge connectorP261 / Connector: C261A,C261C →
Independent review pending

Your next step

Use the distinction in context.

Open the field notes Read source-linked facts and limitations.Compare another pair Start from a common confusion.Check a connection A comparison is not a compatibility verdict.

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Browse every comparison →

PCIe x16 card edge versus MCIO cabled interconnectIs the host interface a card-edge slot or an MCIO/SFF-TA-1016 cabled interconnect family? Connector-family identity is only the first layer; implementation-specific electrical and protocol requirements still need exact documentation.Mini-SAS HD vs OCuLinkMini-SAS HD and OCuLink are different connector families used in high-speed internal links. Physical resemblance is not evidence of mating or protocol compatibility.Mini-SAS HD vs SlimSASMini-SAS HD and SlimSAS are different internal high-density connector families. Match the named SFF form and system documentation, not the general SAS label.SATA data vs SATA powerSATA data and SATA power are separate connectors with different roles and contact counts. Sharing the SATA name does not make them substitutes.CFast versus CFexpress Type BSATA CFast is not PCIe/NVMe CFexpress. Check the full card and reader names before checking performance.CFexpress Type A versus Type BRecord the type letter and supported reader, not just the family name.

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Evidence behind this page

Scope first. Source second. Approval separate.

3 linked sources · 3 scoped claims · 0 sources with inspection/access flags.

Page scope: Evidence behind the compared records; the editorial comparison still needs separate review.

Assessment 2026-10-22 · earliest scheduled source review 2027-01-04. This is a recorded-date assessment, not a live source check. Page-level independent review is not established by this panel.

Inspect 3 source scopes, access limits and dates

S281 · PCI Express x16 164-position card-edge connector

Amphenol Communications Solutions · Manufacturer / product-owner domain · inspected 2026-10-06 · due 2027-01-04

Within inspection window

Scoped support: Identifies a PCI Express x16 vertical card-edge connector with 164 positions; V43 uses form and position count only.

Not established / limitations: Identification/reference scope only. V43 does not convert this source into a universal pinout, fabrication drawing, electrical approval, protocol guarantee or end-to-end compatibility verdict.

Locator: Part specification detail

S338 · Amphenol PCI Express card-edge series — x8 98-position form

Amphenol Communications Solutions · Manufacturer / product-owner domain · inspected 2026-10-06 · due 2027-01-04

Within inspection window

Scoped support: Manufacturer series reference for the PCI Express x8 mechanical/contact-count form only.

Not established / limitations: Source-backed identification does not establish universal wiring, protocol generation, device compatibility, safe installation or fabrication approval.

Locator: Product-series description and standard pin-count/lane-width summary

S429 · PRIME B550-PLUS AC-HES User’s Manual

ASUS · Manufacturer / product-owner domain · inspected 2026-10-08 · due 2027-01-06

Within inspection window

Scoped support: Selected storage and PCIe slot roles for PRIME B550-PLUS AC-HES only, with CPU, slot population and SATA-sharing conditions.

Not established / limitations: Not the ordinary PRIME B550-PLUS or every B550 motherboard. Selected internal groups only; no current BIOS verification, boot qualification, entire port inventory or hardware test. Manual conditions must not be generalized.

Locator: E18712, First Edition, July 2021; specification summary printed vi–vii and layout 1-2. PDF pages 2, 6, 7 and 12 visually inspected.

Trace 3 claims to their source records

C261A · P261

Amphenol identifies part 10146067-113A0LF as a PCI Express x16 card-edge connector with 164 positions.

Claim scope: V43 catalogue-expansion identification fact only; not independent technical approval, fabrication data, wiring instruction, protocol guarantee or end-to-end compatibility proof.

Source links: S281 · Evidence trail → (private workspace)

C261C · P261

The AC-HES manual distinguishes physical x16 slots from wired modes: the chipset PCIe 3.0 x16_4 slot supports x4 mode, falling to x1 when any of the specified x16_2, x16_3 or x16_5 slots is occupied.

Claim scope: E18712 printed vi and layout 1-2; exact board and population condition, not a universal PCIe x16 lane rule.

Source links: S429 · Evidence trail → (private workspace)

C297A · P297

Amphenol identifies the standard PCI Express x8 card-edge connector form with 98 positions/contacts in its PCIe connector range.

Claim scope: V50 identification fact only; no wiring, protocol compatibility, installation or fabrication approval is inferred.

Source links: S338 · Evidence trail → (private workspace)

Prepare this page for review →Read the evidence method →

Recorded evidence only. An inspection date, publisher label, source link or generated packet is not independent technical review, hardware testing, fabrication approval or a compatibility verdict.