Quick Specs Summary
| Spec | Details |
|---|---|
| Display | 14″ 3K OLED |
| CPU | Intel Core Ultra 200V (Lunar Lake) — on-package memory |
| RAM Type | DDR5-8533 (on-package, fused to CPU die) |
| RAM Slots | On-package (inside CPU) |
| Max RAM | 32GB |
| SSD Type | M.2 2280 PCIe Gen 4 NVMe |
| SSD Slots | 1 |
| Charger | 65W USB-C PD |
| Thunderbolt | Thunderbolt 4 |
| Upgradeability | ★★☆☆☆ |
Can You Upgrade the ZenBook S 14?
The ASUS ZenBook S 14 UX5406SA is limited — on-package ram (cannot be upgraded), ssd only. Intel Lunar Lake puts memory INSIDE the CPU package — absolutely zero chance of RAM upgrade. SSD is still replaceable. This is the most locked-down memory design in laptop history, but incredibly fast.
This guide covers exactly which components you can and can’t replace, what compatible upgrades cost, and how to do it safely. We’ll walk through RAM, SSD, charger options, and break down your upgradeability score at the end.
RAM Compatibility
The ASUS ZenBook S 14 UX5406SA uses DDR5-8533 (on-package, fused to CPU die) RAM that is soldered directly to the motherboard. This means you cannot upgrade the RAM after purchase.
When you buy this model, it ships with 16GB / 32GB RAM. If you need more than the configuration available, you’ll need to buy a model with higher RAM spec — there’s no way to upgrade it later. This is unfortunately common in thin-and-light business laptops where Lenovo prioritises minimalism over repairability.
Learn more about soldered vs upgradeable RAM on our RAM compatibility hub.
What RAM Configuration Should I Buy?
Since you can’t upgrade, think carefully about your workflow:
- Light use (web, Office, email): 8GB is adequate but tight by 2026 standards.
- Office work & multitasking: 16GB is the sweet spot for most users.
- Development, virtualisation, creative work: 32GB is strongly recommended.
Buy the configuration you’ll need for the next 3–4 years — you won’t be able to add more later.
SSD/Storage Compatibility
The ASUS ZenBook S 14 UX5406SA has 1 × M.2 2280 PCIe Gen 4 NVMe slot. You can replace the SSD with a faster or larger model.
Compatible SSD Drives
| Drive | Spec | Price |
|---|---|---|
| Samsung 990 Pro 1TB | M.2 2280 PCIe Gen 4 | £85 |
| WD Black SN850X 1TB | M.2 2280 PCIe Gen 4 | £75 |
| Crucial P5 Plus 1TB | M.2 2280 PCIe Gen 4 | £60 |
Charger Compatibility
The ASUS ZenBook S 14 UX5406SA charges via USB-C Power Delivery at 65W. This is excellent news — you can use compatible third-party chargers, charge from power banks, and simplify your cable collection.
Compatible USB-C Chargers
| Charger | Spec | Price |
|---|---|---|
| Anker Prime 67W GaN | USB-C PD 67W | £32 |
| Ugreen Nexode 65W | USB-C PD 65W | £28 |
Browse USB-C chargers on Amazon UK
Dock & Peripheral Compatibility
The ASUS ZenBook S 14 UX5406SA features Thunderbolt 4, which means you can use premium docking stations and achieve blazing-fast data transfers (up to 40 Gbps).
Top dock choices for Thunderbolt 4 machines:
- CalDigit TS4 — 98W charging, 6 × USB-A, Ethernet, SD card (£320)
- Anker 568 Dock — 65W charging, 3 × USB-A, HDMI (£45)
View our full dock compatibility guide.
Upgradeability Score Breakdown
| Component | Score | Notes |
|---|---|---|
| RAM | ☆☆☆☆☆ | Soldered — no upgrade |
| SSD | ★★★★★ | Replaceable M.2 |
| Charger | ★★★★☆ | USB-C PD — use any compatible charger |
| Overall | ★★☆☆☆ | Composite score across all upgradeable components |
How to Upgrade
Upgrading RAM or SSD in the ASUS ZenBook S 14 UX5406SA is straightforward and doesn’t require special tools beyond a Phillips #0 screwdriver.
RAM upgrade: Open the access panel on the underside, push the retention clips on the SO-DIMM slot, and slide in your new module at a 45° angle. Power off first!
SSD upgrade: Remove the M.2 cover, unscrew the drive retention screw, and slide in your new NVMe at the same 45° angle.
Check iFixit for a detailed ZenBook S 14 teardown guide before you start — it’s always good to see exactly what you’re working with.
Return to the ASUS laptop upgrade hub.
Frequently Asked Questions
What RAM does the ASUS ZenBook S 14 UX5406SA use?
The ASUS ZenBook S 14 UX5406SA uses DDR5-8533 (on-package, fused to CPU die) in On-package (inside CPU) slots (soldered to the motherboard). Maximum capacity is 32GB.
Can I upgrade the RAM in the ASUS ZenBook S 14 UX5406SA?
No — the RAM is soldered to the motherboard and cannot be upgraded. Choose your RAM configuration carefully at purchase.
What SSD fits the ASUS ZenBook S 14 UX5406SA?
An M.2 2280 PCIe Gen 4 NVMe SSD fits the ASUS ZenBook S 14 UX5406SA. Current options include the Samsung 990 Pro, WD Black SN850X, and Crucial P5 Plus.
What charger does the ASUS ZenBook S 14 UX5406SA need?
The ASUS ZenBook S 14 UX5406SA requires a 65W USB-C PD charger. Any compatible USB-C PD charger rated for this wattage will work.
Is the ASUS ZenBook S 14 UX5406SA good for upgrading?
Limited — on-package ram (cannot be upgraded), ssd only. Intel Lunar Lake puts memory INSIDE the CPU package — absolutely zero chance of RAM upgrade. SSD is still replaceable. This is the most locked-down memory design in laptop history, but incredibly fast.
Recommended Products
These are the products we recommend based on this guide. All links go to Amazon UK where you can check current prices and availability.
| Product | Why We Recommend It | Amazon UK |
|---|---|---|
| Corsair Vengeance DDR5 SO-DIMM 32GB (2×16GB) 5600MHz | Top-rated DDR5 kit for gaming & productivity | View on Amazon UK |
| Kingston Fury Impact DDR5 SO-DIMM 32GB (2×16GB) 5600MHz | Excellent DDR5 alternative with XMP support | View on Amazon UK |
| Crucial DDR5 SO-DIMM 16GB 5600MHz | Affordable single-stick DDR5 | View on Amazon UK |
| G.Skill Ripjaws DDR5 SO-DIMM 32GB 5600MHz | High performance DDR5 for enthusiasts | View on Amazon UK |
| Samsung 990 Pro 2TB NVMe M.2 2280 | Fastest consumer NVMe — ideal for gaming & editing | View on Amazon UK |
| WD Black SN850X 2TB NVMe | Excellent Gen4 speed with heatsink option | View on Amazon UK |
| Crucial P5 Plus 1TB NVMe | Great value Gen4 SSD | View on Amazon UK |
| Kingston NV2 1TB NVMe | Budget-friendly with solid reliability | View on Amazon UK |
Prices and availability may vary. As an Amazon Associate, we earn from qualifying purchases.
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