G.SKILL
G.SKILL Ripjaws S5 Series DDR5 RAM (Intel XMP 3.0) 64GB (2x32GB) 6400MT/s CL32-39-39-102 1.40V Desktop Computer Memory U-DIMM - Matte Black (F5-6400J3239G32GX2-RS5K)
Bottom line: The G.SKILL Ripjaws S5 Series DDR5 RAM: 64GB delivered as 2x32GB, leaving two slots free on a four-slot board; main trade-off: intel XMP 3.0 only, with no AMD EXPO profile listed for AM5 boards.
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Pros & Cons
Pros
- ✓ 64GB delivered as 2x32GB, leaving two slots free on a four-slot board
- ✓ Rated DDR5-6400 CL32-39-39-102 profile enables from a single Intel XMP 3.0 BIOS toggle
- ✓ Hits its 6400MT/s rating at 1.40V per G.SKILL's published spec
- ✓ JEDEC default SPD profile boots at stock BIOS settings before any tuning
Cons
- ✗ Intel XMP 3.0 only, with no AMD EXPO profile listed for AM5 boards
- ✗ Non-ECC modules, so ECC-required workstation and server builds are out
- ✗ 6400MT/s depends on your motherboard and CPU memory controller, not guaranteed
- ✗ Cannot be combined with a second kit for 128GB; G.SKILL warns of instability
Manufacturer description
The G.SKILL Ripjaws S5 DDR5 kit (F5-6400J3239G32GX2-RS5K) puts 64GB into two 32GB U-DIMMs, so a four-slot board keeps half its slots open and a two-slot micro-ATX or mini-ITX build still reaches the full 64GB. The rated profile is DDR5-6400 at CL32-39-39-102 and 1.40V, delivered through Intel XMP 3.0, and G.SKILL lists validation for Intel Z890, Z790 and B760 platforms with per-board detail in its QVL and RAM Configurator tool. Out of the box the modules boot at their JEDEC default SPD speed on compatible hardware, so you get a stable system first and the 6400MT/s profile second: enabling…
SpecPicks Verdict
SpecPicks scored G.SKILL Ripjaws S5 Series DDR5 RAM (Intel XMP 3.0) 64GB (2x32GB)… using a rating × review-volume × price-fit model applied to published specs and reviews across the memory (ram) category. G.SKILL's memory (ram) lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.
Common buyer scenarios for memory (ram) of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.
Frequently Asked Questions
Will this kit run at 6400MT/s on an AMD Ryzen board?
G.SKILL lists this kit for Intel Z890, Z790 and B760 platforms and includes only a JEDEC default profile plus an Intel XMP 3.0 overclock profile, not EXPO. Check the G.SKILL QVL or RAM Configurator for your specific board before buying.
Do I have to change BIOS settings to get the advertised speed?
Yes. The modules boot at their JEDEC default SPD speed at default BIOS settings. To reach DDR5-6400 CL32-39-39-102 you must enable the XMP profile in BIOS, which is an act of overclocking.
Can I buy two of these kits to get 128GB?
G.SKILL advises against it. The 2x32GB modules are sold as a matched kit designed to run together as a set, and mixing kits can cause stability issues or system failure. Buy the capacity you need in one kit.
What are the exact timings, voltage and module type?
CL32-39-39-102 at 1.40V for the rated DDR5-6400 XMP profile. The modules are non-ECC 288-pin DDR5 U-DIMMs for desktop and gaming PCs, two 32GB sticks for 64GB total, in a matte black finish.
Key Features
- G.SKILL Ripjaws S5 Series DDR5 U-DIMM Memory Kit, Model: F5-6400J3239G32GX2-RS5K
- 64GB total capacity kit containing 2x32GB modules, rated for up to DDR5-6400 CL32-39-39-102 at 1.40V
- Non-ECC, DDR5 U-DIMM, 288-pin, for Desktop PC & Gaming
- Includes JEDEC default profile, and Intel XMP 3.0 memory overclock profile
- Do not mix memory kits. Memory kits are sold in matched kits that are designed to run together as a set. Mixing memory kits will result in stability issues or system failure.
- For Intel Z890, Intel Z790, Intel B760 platforms. Refer to G.SKILL memory QVL or RAM Configurator tool on the G.SKILL website for more details on validated motherboard and hardware.
Full Specifications
| Brand | G.SKILL |
|---|---|
| Voltage | 1.4 volts |
| RAM Size | 64 GB |
| Model Name | RipJaws S5 |
| Form Factor | DIMM |
| Memory Speed | 6400 mt_s |
| Model Number | F5-6400J3239G32GX2-RS5K |
| Compatibility | PC |
| Item Type Name | DDR5 SDRAM Intel XMP |
| Number of Pins | 288 |
| Mfr Part Number | F5-6400J3239G32GX2-RS5K |
| Memory Generation | DDR5 |
| Compatible Devices | Desktop |
| Data Transfer Rate | 6400 MHz |
| Memory Form Factor | UDIMM |
| Additional Features | Intel XMP 3.0 |
| Computer Memory Size | 64 GB |
| Warranty Description | Limited Lifetime Manufacturer |
| RAM Memory Technology | DDR5 |
| Column Address Strobe Latency | 32 |
Ready to buy?
G.SKILL Ripjaws S5 Series DDR5 RAM (Intel XMP 3.0) 64GB (2x32GB) 6400MT/s CL32-39-39-102 1.40V Desktop Computer Memory U-DIMM - Matte Black (F5-6400J3239G32GX2-RS5K) is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
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