PCIe 4.0 or 5.0 SSD for gaming? Check load times, capacity and slot sharing

Who this guide is for and what to prepare

People choosing a gaming SSD for a custom PC
Owners weighing the extra cost of replacing a Gen4 SSD with Gen5

What you need

Estimate current games, recordings and work files plus expected growth
Record the CPU, motherboard, M.2 slot numbers and existing SSD models

For gaming, compare capacity and measured behavior first

PCIe generation describes an interface constraint. Actual waiting time also depends on the game's processing, CPU, transfer destination, cache, drive capacity and temperature. This table organizes buying decisions; it does not rank every Gen4 and Gen5 drive.

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For gaming, compare capacity and measured behavior first
Use or constraint	Start with Gen4 when	Consider a Gen5 premium when
Game storage and launching	Capacity and game measurements meet the need	Measured benefits matter in your actual games
Repeated large-file copies	The existing source or destination limits throughput	Both ends are fast and sustained-transfer tests justify it
A large game library	It provides the required capacity within budget	The faster model does not sacrifice required capacity
An existing Gen4 board	You intend to keep it	Backward compatibility and a planned future move justify it
Thin cases or laptops	A model meets space and cooling requirements	Thickness, power and cooling requirements all fit
Several occupied slots	The layout satisfies sharing rules	You have checked effects on other devices

What a same-system gaming comparison shows

TechSpot's August 12, 2025 article measured manufacturer-supplied SSDs on one PC with a Ryzen 7 9800X3D, RTX 5090 and 32GB DDR5-6000. M.2 drives used the CPU-connected slot, with the OS on a separate drive. These are the outlet's measurements, not ours.

These observations apply to that test's models, capacities and game versions. They do not establish identical results for every SSD or every game in 2026.

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What a same-system gaming comparison shows
Test	Reported result	How to use it
F1 25 loading	The tested PCIe SSDs loaded in the same time	Do not estimate time saved from Gen5 throughput alone
The Last of Us Part II loading	No meaningful loading difference between tested PCIe NVMe drives	DirectStorage use alone does not establish a Gen5 requirement
Initial loads versus save reloads	Some reload tests reduced differences between SSDs	Compare the operation you actually wait for

For large copies, inspect sustained writes

In the same TechSpot testing, copying a 123GB game onto the Gen4 A440 took 38% less time than onto the Gen4 A440 Lite. The article discusses cache differences. Models within one generation can differ substantially, beyond their headline write speeds.

When reviewing a candidate, check speed after its write cache is exhausted, free space, temperature and tested capacity alongside short benchmarks. Do not automatically transfer a 2TB model's results to the same family's 1TB or 8TB version.

If the other end is a slower SSD, USB device or network, upgrading only the internal SSD may not reduce total transfer time proportionally. Define the source, destination, batch size and frequency first.

Check M.2 sharing rules and CPU-dependent limits

The M.2 form factor alone does not establish PCIe generation, lane width or supported drive length. Read each numbered slot's specification for your CPU and its shared connections. An empty slot may not provide the connection you expect.

For example, on the TUF GAMING X870-PLUS WIFI with a Ryzen 9000 or 7000 CPU, using M.2_2 makes the shared PCIEX16(G5) slot operate at x8. M.2_2 is unsupported with Ryzen 8000 CPUs. Using M.2_4 also disables the separate PCIEX16(G4) slot. These rules apply to this board.

A change from x16 to x8 does not by itself mean GPU frame rates halve; measuring your GPU and workload is needed to determine the effect. First consider whether another SSD placement avoids sharing while preserving required expansion cards.

Include cooling and heatsink clearance

Do not assume every Gen5 model is equally hot or needs no cooling. Check product cooling guidance, the board's heatsink, nearby GPU clearance and airflow. Use the installation instructions to determine whether the SSD's own heatsink and the board's cover can coexist.

Samsung specifies a maximum height of 8.88mm for 1–4TB 9100 PRO with Heatsink models and 11.25mm for 8TB. Fit therefore changes even within one family. Its documentation instructs owners not to remove the factory heatsink, so do not buy it planning to remove that heatsink to make it fit.

Match temperature readings to the product's specified sensor and operating range. Readouts differ between drives, so do not copy a threshold from another model. If a long transfer slows down, investigate both cooling and cache behavior.

Compare the SSD, cooling and any platform replacement

Hold required capacity constant and compare the SSD plus necessary cooling and any motherboard replacement or installation cost. Sacrificing capacity for peak speed can create different waiting time through moving or downloading games again.

A compatible Gen5 SSD in a Gen4 system does not provide a Gen5 connection. Samsung documents backward compatibility with Gen4 x4 and Gen3 x4 for the 9100 PRO. Separate today's connection from a future move, and do not pay a large premium solely because it is compatible.

This article does not claim current Japanese lowest prices or a price ranking. Quote matching capacities and new-product condition on the purchase date, including heatsink, Japanese warranty and shipping. Advertised throughput is a manufacturer's conditional specification, separate from the game measurements above.

A purchase and installation checklist

Replacing the OS drive involves more work than adding a game drive. Preserve required files and recovery information before choosing cloning or a clean installation. If initializing a disk after installation, first verify the target's model and capacity.

Estimate capacity separately for games, recordings, the OS and work files
Compare same-capacity candidates using game and sustained-write measurements
Match CPU, numbered M.2 slot, sharing rules and SSD dimensions
Check the manual for heatsink, thermal pads and mounting method
Save necessary data elsewhere, then power off before installation
Verify the detected model, capacity and connection before transferring data

After upgrading, measure the waits that matter to you

Record initial game loads, save reloads and recording-file copies separately. Keep game version, source and destination, data size, free space and background activity consistent; do not judge the upgrade from a single run.

If a Gen5 drive connects at Gen4 or below, first recheck the slot and CPU specifications. Manufacturers also identify BIOS, SSD firmware and drivers as factors. Before updating, back up data and read the changes relevant to the exact model.

Sources were checked on September 12, 2026. The gaming evidence is from an August 2025 test and does not predict future games or new SSD models.

Limitations and requirements

Do not translate advertised sequential-throughput ratios into equivalent changes in loading time, FPS or total task time.
Check sharing rules for the exact motherboard and CPU combination.
The reported measurements belong to the cited outlet; we have not physically benchmarked these SSDs.

Frequently asked questions

Is PCIe 5.0 unnecessary for gaming?

There is no universal answer. Compare capacity, price premium and your titles. Before paying a large premium for loading alone, inspect a same-capacity Gen4 alternative and consider recording or transfer workloads.

Will a Gen5 SSD be damaged by a Gen4 slot?

Documented backward-compatible models can work in an appropriate M.2 slot, at the lower connection capability. Still verify form factor, length, cooling and CPU-dependent restrictions.

Does adding an M.2 SSD halve GPU performance?

A reduction in lane count does not mean a proportional reduction in FPS. Check whether the selected slot shares bandwidth and how the connection changes, then consult measurements for the same GPU and games if the effect matters.

Sources and verification date

Sources checked: 2026-09-12. These sources support the specifications, procedures or prices discussed here. Check each source for applicable conditions and current information.

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