Samsung ViewFinity S9 (S27C900P) 5K60 DisplayPort Failure — NVIDIA Confirms Compatibility Issue

I am reporting a reproducible DisplayPort compatibility issue with the Samsung ViewFinity S9 (S27C900P) and recent NVIDIA drivers. I am requesting that Samsung moderators escalate this issue to the monitor firmware engineering team.

My configuration:

Monitor: Samsung ViewFinity S9 (S27C900P)

Firmware: 2231

GPU: MSI GeForce RTX 5090 VENTUS 3X OC

OS: Windows 11 Pro 24H2

Connection: DisplayPort to Mini DisplayPort

Native resolution: 5120 × 2880 @ 60 Hz

Confirmed driver regression:

WORKING:

NVIDIA 591.74

NVIDIA 591.86

FAILING (black screen / No Signal at 5K60):

595.79, 596.21, 596.36, 596.49

610.47, 610.62, 610.88

616.56, 616.92, 617.14, 617.42

The regression on my system was introduced after 591.86 and no later than 595.79.

With NVIDIA 617.42, the Samsung monitor loses signal during driver installation, displays a black screen, and eventually enters standby. Rebooting does not resolve the problem. Rolling back to 591.86 restores native 5K60 operation.

Lower-bandwidth modes, including 5K30, work with affected drivers.

Official response from NVIDIA
I contacted NVIDIA support under Incident 260717-000025 and received the following response:

Thank you for your feedback. We have looked into this in the past for this particular monitor and confirmed this is not a driver issue. The reason the older driver does not show this problem is that the older driver did not support or expose a new display technology used by some newer monitors such as yours and falls back to using EDID. Please reach out to Samsung for further support.

NVIDIA therefore attributes the failure to a compatibility issue involving a newer display technology or capability negotiation path. However, NVIDIA has not identified the specific feature involved.

Technical diagnostics
I performed controlled A/B testing between working and failing driver states.

Both states report:

Identical 5120 × 2880 @ 59.993 Hz timing

938.25 MHz pixel clock

RGB 8 bpc, Full Range, SDR

DisplayPort HBR3 ×4

Byte-for-byte identical 512-byte EDID

All four DP lanes reporting successful clock recovery, channel equalization and symbol lock

Interlane alignment complete

DSC and FEC disabled

One consistent DPCD difference was observed:

591.74 / 5K60 / WORKING: 0x205 = 0x07

617.14 / 5K30 / WORKING: 0x205 = 0x07

617.14 / 5K60 / NO SIGNAL: 0x205 = 0x03

This is an observed correlation, not proof of the root cause.

The available measurements suggest that the failure occurs after or above basic DisplayPort link establishment, potentially during main-stream initialization or sink-side processing.

Request to Samsung
Could a Samsung moderator or technical representative please:

Escalate this issue to the Samsung ViewFinity S9 firmware/display engineering team.

Confirm whether Samsung is already investigating this compatibility issue.

Identify the newer DisplayPort feature or capability referenced by NVIDIA.

Clarify whether a firmware update is being developed.

Provide a Samsung technical case/reference number or a channel for submitting detailed engineering logs.

I have a complete technical report with EDID comparisons, NVAPI measurements and read-only DPCD diagnostics, which I can provide to Samsung engineering.

Multiple ViewFinity S9 owners have reported similar 5K60 failures. This appears to be a broader compatibility issue rather than an isolated hardware fault.

Samsung ViewFinity S9 owners should not have to remain on outdated NVIDIA drivers to use the monitor's advertised native 5K60 mode.

Thank you.