Selling an open-box Corsair Vengeance DDR5 128GB kit (2 x 64GB), model CMK128GX5M2B6400C42.

Opened only to validate operation, run MemTest86, and photograph the kit. Use has been limited to this testing and documentation.

Per Corsair specifications, this kit features DDR5-6400 (PC5-51200), 128GB capacity across two 64GB modules, CL42, 1.35V tested voltage, and Intel XMP 3.0 support. These are black 288-pin DDR5 UDIMMs with aluminum heatspreaders. The XMP profile shown in the attached validation screenshots is 6400 MT/s at 42-52-52-104; the default SPD specification is 4800 MT/s CL40 at 1.1V.

Condition

Functional: Validated on an Intel Core Ultra 9 285K / ASUS ROG Maximus Z890 Hero system. The attached MemTest86 V11.7 Pro report generated October 30, 2026 shows PASS, with 60/60 tests passed and zero errors. Each listed test completed 4/4 passes, with a total elapsed time of 10 hours, 24 minutes, 12 seconds. Testing began on October 29, 2026, and the report records operation at 6400 MT/s with 42-52-52-104 timings.

The accompanying CPU-Z, HWiNFO, and Windows Task Manager screenshot shows 128GB detected, two memory slots occupied, and operation at 6400 MT/s. These results document this kit on the Intel test system shown.

Cosmetic: Open box, opened only for validation, testing, and photographs. Please review the listing photos for the exact physical condition.

Included

• One Corsair Vengeance 128GB (2 x 64GB) DDR5-6400 CL42 kit, model CMK128GX5M2B6400C42
• Original retail packaging (opened for validation testing and photography)

Compatibility / Technical Notes

This is an Intel XMP kit; Corsair lists Intel 700-series and 800-series compatibility. Confirm that your specific motherboard, CPU, and BIOS support 64GB DDR5 UDIMMs and this kit's total capacity. Check the motherboard's memory QVL before purchasing.

The rated 6400 MT/s setting requires XMP or appropriate BIOS configuration. Maximum attainable speed and stability depend on the CPU memory controller, motherboard, BIOS, and memory configuration. The Intel validation shown does not guarantee the same settings on every system. At default BIOS settings, the kit uses its SPD profile.

These are desktop UDIMMs. They are not laptop SO-DIMMs or registered workstation/server RDIMMs.

Buyer Notes

• Sold exactly as pictured and described.
• This listing is for one 128GB kit containing two 64GB modules.
• Please confirm motherboard and CPU memory compatibility before purchasing.
• For fraud prevention and shipment verification, all item serial numbers are recorded and logged prior to shipment.
• Item condition and packaging are photographed/recorded before shipment to help prevent shipping or return disputes.

References

• Corsair product page
• PCPartPicker listing
• Amazon product page

Tags

Corsair, Vengeance, DDR5, 128GB, 2x64GB, DDR5-6400, 6400 MT/s, CL42, CMK128GX5M2B6400C42, Intel XMP 3.0, desktop memory, workstation RAM, open box, MemTest86