PCIe Gen4 vs Gen5: Which SSD Should You Choose?

A Complete Technical Guide for 2026

In 2017, PCIe Gen4 arrived, doubling the bandwidth of Gen3 and promising unprecedented storage performance. Just two years later, in 2019, PCIe Gen5 was released—yet another doubling of speed. This rapid evolution left many users wondering: Do I really need Gen5, or is Gen4 still the sweet spot? With Gen4 SSDs now mature and affordable, while Gen5 commands a premium price, the choice isn't just about raw speed—it's about real-world value. Let's break down what actually matters for your setup.

The Speed Dilemma: Why You're Confused

Ever found yourself stuck in this situation?

You just built a gaming PC with the latest CPU and GPU. Maybe it's a Ryzen 7 7800X3D or an Intel Core i9-14900K. You dropped serious cash on an RTX 4090. But when you get to the storage selection, you freeze.

ON2000PRO claims 13,000 MB/s. ON1000X does 7,400 MB/s. The price difference isn't even that huge. Your motherboard has "PCIe 5.0 M.2" printed right on the box.

But then you start second-guessing. Will you actually notice the difference? Is Gen5 worth the extra cost? What if your motherboard only supports one Gen5 slot and you want to run multiple drives? Are you buying into technology you can't fully use yet?

Or maybe you're on the other side. You bought a Gen4 drive last year, and now you're wondering if you missed out. Should you upgrade? Is your storage already obsolete?

The frustration is real. The marketing numbers sound impressive—75% faster sounds massive. But what does that actually mean for your daily use?

The question isn't which is faster—it's which is right for YOU.

Let's cut through the noise and look at what actually matters.

Technical Deep Dive: What Actually Changed Between Gen4 and Gen5

PCIe Protocol Evolution

PCIe (Peripheral Component Interconnect Express) is the highway data travels between your SSD and the rest of your system. Each generation doubles the bandwidth:

Generation	Release Year	Bandwidth (per lane)	Real-World Speed
PCIe Gen3	2010	8 GT/s	3,500 MB/s
PCIe Gen4	2017	16 GT/s	7,400 MB/s
PCIe Gen5	2019	32 GT/s	13,000 MB/s

Notice the pattern: each generation doubles the theoretical bandwidth. But theoretical maximum isn't the same as real-world performance.

Real-World Performance Testing Data

Here's what you can actually expect from Oscoo drives:

CrystalDiskMark Sequential Read (Q8T1):

• ON2000PRO (PCIe Gen5): 13,000 MB/s

• ON1000X (PCIe Gen4): 7,400 MB/s

• ON900 (PCIe Gen3): 3,500 MB/s

On paper, Gen5 looks 75% faster. But sequential reads don't tell the whole story.

4K Random Read (IOPS) - The Metric That Actually Matters:

Most daily operations—booting Windows, loading games, launching applications—depend on random read performance, not sequential.

Here's what industry testing actually shows:

Metric	Gen4 (Samsung 990 Pro)	Gen5 (Crucial T700)	Improvement
Sequential Read	7,000 MB/s	12,400 MB/s	~75% faster
4K Random Read (QD1)	80.6 MB/s (~20K IOPS)	73.8 MB/s (~19K IOPS)	Actually slower
4K Random Read (Q32T1)	327K IOPS	1.2M IOPS*	~265% faster

*Q32T1 = Queue Depth 32, Thread 1 (synthetic benchmark, not real-world)

The critical insight: Random 4K performance at QD1 (Queue Depth 1)—which represents real-world desktop usage—shows virtually NO improvement from Gen4 to Gen5. In some cases, Gen5 drives are actually slightly slower due to thermal throttling.

As Tom's Hardware notes in their 2025 SSD benchmarks:

"It should be immediately obvious that there's not much difference between the various PCIe 3.0, 4.0, and 5.0 drives when it comes to QD1 random I/O... Even the fastest drives are less than twice the random I/O performance of the slowest drives."

The 75% improvement figure only applies to sequential transfers (large file copies). For the snappy, responsive feel you notice daily, Gen4 and Gen5 are nearly identical.

File Transfer Examples - Where Gen5 Actually Shines:

This is where you'll feel the difference most:

• 100GB video file: ON2000PRO (~79 seconds) vs ON1000X (~139 seconds) = 43% faster

• Steam game copy (50GB): ON2000PRO (~40 seconds) vs ON1000X (~70 seconds)

• 500GB photo backup: ON2000PRO saves ~5 minutes vs Gen4

If you regularly move hundreds of gigabytes, Gen5 is legitimately useful. If you don't, you might never notice.

Compatibility Check: Will Your Motherboard Actually Support Gen5?

Before getting excited about Gen5 speeds, you need to verify your system can actually deliver them.

Intel Platform Support

Intel introduced PCIe 5.0 support with their 12th Gen Alder Lake platform:

Chipset	PCIe 5.0 Support	Notes
Z690/Z790	Yes	Usually CPU slot 1 only
Z590 and older	No	PCIe 4.0 maximum
B660/B760	No	PCIe 4.0 only
H670/H770	No	PCIe 4.0 only

Important: Even on Z690/Z790 boards, only the M.2 slot connected directly to the CPU (usually slot 1) supports PCIe 5.0. Other slots are PCIe 4.0 or 3.0.

CPU Requirement: You need a 12th, 13th, or 14th Gen Intel CPU. 11th Gen and older don't support PCIe 5.0.

AMD Platform Support

AMD brought PCIe 5.0 with the AM5 platform (Ryzen 7000 series):

Chipset	PCIe 5.0 Support	Notes
X670E/X670	Yes	Usually first M.2 slot
B650E	Yes	Typically one Gen5 slot
B650	No	PCIe 4.0 only
AM4 (older)	No	PCIe 4.0 maximum

CPU Requirement: Ryzen 7000 series or newer (Ryzen 9000 when available).

Backward Compatibility Explained

This is crucial: PCIe is fully backward compatible.

• A Gen5 SSD in a Gen4 slot works fine, but runs at Gen4 speeds

• A Gen4 SSD in a Gen5 slot runs at Gen4 speeds (doesn't magically get faster)

• A Gen4 SSD in a Gen3 slot runs at Gen3 speeds

What this means for you: You CAN buy an ON2000PRO (Gen5) today even if your current motherboard only has Gen4 slots. It'll run at Gen4 speeds now, but if you upgrade your motherboard later, you'll unlock full Gen5 performance.

This is a valid future-proofing strategy—but only if you actually plan to upgrade within the drive's warranty period.

PS5 Special Note

PS5 storage expansion has specific requirements:

• Must be PCIe Gen4 (Gen3 too slow, Gen5 wastes money)

• Must read at least 5,500 MB/s

• Must have a heatsink

The reality: PS5 caps at PCIe Gen4 speeds. A Gen5 drive will work, but you're paying for performance you can't use.

Recommendation: ON1000PRO is the PS5 sweet spot. It hits 7,500 MB/s (well above Sony's 5,500 MB/s requirement) and comes with a built-in heatsink.

Who Actually Needs Gen5? User Group Analysis

Let's break this down by user type. Be honest about which category you fall into.

High-End Gamers

You MIGHT need Gen5 if:

You have a Ryzen 7000X3D or Intel 13th/14th Gen i7/i9 AND you play games with massive open worlds that stream assets continuously.

Think titles like:

• Starfield

• Cyberpunk 2077 with ray tracing

• Microsoft Flight Simulator

• Ark: Survival Evolved with heavily modded worlds

The reality check: Most games see less than 10% improvement going from Gen4 to Gen5.

Here's why: Game developers optimize for common hardware. Most console players (PS5/Xbox Series X) are running storage slower than your Gen4 drive. Developers aren't building games that require 13,000 MB/s because almost nobody has that.

Frame rate impact: Zero. Your SSD doesn't affect FPS once the game is loaded.

Level loading times: You might save 2-5 seconds per load. Nice to have, but is it worth the premium?

Verdict for gamers:

• 95% of gamers: ON1000X (Gen4) is plenty

• Ultra enthusiasts with unlimited budget: ON2000PRO (Gen5)

Content Creators (Video/3D/Photography)

You DO need Gen5 if:

You work with large files professionally and time literally equals money.

Specifically:

• 8K video editors: Raw 8K footage eats storage bandwidth for breakfast

• Photographers editing 100MP+ RAW files: Large batch imports/exports

• 3D artists and VFX professionals: Scene files can be hundreds of GB

• DaVinci Resolve, Premiere Pro, After Effects users: These apps benefit from faster scratch disks

The math: If you move 500GB of project files daily, Gen5 saves you about 5 minutes per day. That's 25 minutes per week, ~100 minutes per month. For a professional, that's meaningful.

Cache files and scratch disks: Video editing apps create massive temporary files. Faster storage means smoother timeline scrubbing and faster renders.

Verdict for creators:

• Professional 4K/8K video: ON2000PRO (Gen5)

• YouTube/indie creators: ON1000X (Gen4) is usually enough

• Photographers: ON1000X unless you're working with massive RAW batches

PS5/Console Gamers

You DON'T need Gen5. Full stop.

PS5 storage expansion is capped at PCIe Gen4 speeds. A Gen5 drive will work, but you're literally paying for performance your PS5 cannot use.

What you DO need:

• PCIe Gen4 NVMe SSD

• At least 5,500 MB/s read speed

• A heatsink (mandatory)

Verdict for PS5:

• Best choice: ON1000PRO (built-in heatsink, 7,500 MB/s)

• Budget choice: ON1000X + separate heatsink

General Users / Office PC

You probably don't need Gen4 either.

If your workload is:

• Web browsing

• Office apps (Word, Excel, PowerPoint)

• Email

• Light gaming

Then even PCIe Gen3 (ON900 at 3,500 MB/s) is overkill. A SATA SSD would feel fast for these tasks.

Verdict for general users:

• Budget-conscious: ON900 (Gen3)

• Future-proofing without breaking the bank: ON1000X (Gen4)

• Gen5 is completely unnecessary

Thermal and Power Considerations

Faster isn't free. Gen5 drives have real thermal challenges you need to understand.

Gen5 Thermal Challenges

PCIe Gen5 SSDs consume significantly more power:

• ON2000PRO (Gen5): ~10-12W under sustained load (can exceed 14W under boost)

• ON1000X (Gen4): ~6-8W under sustained load

More power = more heat. Without proper cooling, Gen5 drives will throttle—dropping from 13,000 MB/s to much lower speeds to protect themselves.

What this means for you:

Gen5 drives REQUIRE substantial cooling:

• Motherboard M.2 heatsink (must make full contact)

• Or aftermarket heatsink/fan combination

• Active cooling (fan) recommended for sustained writes

Real-world temperatures:

• ON2000PRO under load: 65-75°C (with good heatsink)

• ON1000X under load: 50-60°C (with heatsink)

Most SSDs start throttling around 80°C. If your case has poor airflow, a Gen5 drive might never hit its advertised speeds.

Gen4 Thermal Advantages

Gen4 drives run cooler and are easier to cool:

• Lower power consumption

• Many motherboards have adequate Gen4 cooling built-in

• Less likely to throttle in real-world use

Practical implication: Gen4 is more "set it and forget it." Gen5 requires attention to cooling.

Price vs Performance Analysis

Let's talk about value.

Current pricing trends (2026):

• Gen5 (ON2000PRO): Typically commands a premium over Gen4 (varies by model and market)

• Gen4 (ON1000X): Sweet spot pricing

• Gen3 (ON900): Budget-friendly

The value equation:

You're paying 30-50% more for roughly 75% more sequential speed. But remember:

• Real-world gaming improvement: <10%

• Large file transfers: 30-40% faster

• Most daily tasks: No noticeable difference

Break-even analysis:

For a professional whose time is worth $50/hour, saving 5 minutes daily on file transfers adds up. Over a year, that's 20+ hours saved—$1000+ of value.

For a gamer saving 3 seconds per level load... you do the math.

Oscoo Product Recommendations

Based on everything above, here are specific Oscoo recommendations for each use case.

For Gen5 Seekers: ON2000PRO

Specifications:

• 13,000 MB/s read, 11,800 MB/s write

• M.2 2280 form factor (standard size)

• PCIe Gen5 x4

• Independent DRAM cache for consistent performance

Best for:

• Extreme performance enthusiasts

• 8K video editors

• 3D rendering and VFX professionals

• Users with Z690/Z790 or X670E motherboards who want maximum speed

Before you buy, verify:

• Your motherboard has a PCIe 5.0 M.2 slot

• Your CPU supports PCIe 5.0 (12th Gen Intel or newer, Ryzen 7000 or newer)

• You have adequate cooling (motherboard heatsink or aftermarket)

• Your workflow actually benefits from faster storage

Capacity recommendation: 2TB is the sweet spot for price/capacity ratio.

For the Gen4 Sweet Spot: ON1000X

Specifications:

• 7,400 MB/s read, 6,500 MB/s write

• M.2 2280 form factor

• PCIe Gen4 x4

• HMB (Host Memory Buffer) technology instead of DRAM cache

Best for:

• PC gamers (95% of you)

• Most content creators (4K video, photography)

• Users wanting future-proofing without the Gen5 premium

• Anyone with a modern motherboard

Why it's the sweet spot:

• Fast enough that you won't notice it's slow

• Works in virtually any modern system

• Runs cooler than Gen5

• Better value per GB

PS5 note: ON1000X works in PS5, but you MUST add a heatsink. Or just get ON1000PRO instead.

Capacity recommendation: 1TB for gaming, 2TB for content creation.

For PS5 Specifically: ON1000PRO

Specifications:

• 7,500 MB/s read, 6,800 MB/s write

• M.2 2280 with BUILT-IN HEATSINK

• PCIe Gen4 x4

• DRAM cache included

Best for:

• PS5 storage expansion (drop-in solution)

• Builds where you want integrated cooling

• Users who want plug-and-play simplicity

Why it's perfect for PS5:

• Exceeds Sony's 5,500 MB/s requirement

• Built-in heatsink (no extra purchase needed)

• DRAM cache for consistent performance

• Just works

This is the PS5 recommendation. No need to consider anything else.

For Budget Builds: ON900

Specifications:

• 3,500 MB/s read, 3,000 MB/s write

• M.2 2280 form factor

• PCIe Gen3 x4

Best for:

• Office PCs

• Budget gaming builds

• Older systems without PCIe 4.0 support

• Upgrading pre-built PCs

The reality: 3,500 MB/s is still incredibly fast. If you're coming from a SATA SSD or hard drive, ON900 will feel like magic.

Making Your Decision: A Step-by-Step Guide

If you're still unsure, follow this process:

First, check your motherboard manual. Look for the M.2 slot specifications. It will tell you which slots support which PCIe generations.

Next, identify what generation your primary M.2 slot supports. Gen3, Gen4, or Gen5? This is your hard ceiling—you can't exceed what your hardware allows.

Then, consider your primary use case. Be honest with yourself:

• Gaming? Gen4 is usually enough.

• Professional video/3D work? Gen5 might be worth it.

• PS5? Gen4 with heatsink.

• General use? Even Gen3 is fine.

After that, set your budget. Gen5 commands a premium. Is the performance gain worth the extra cost for YOUR specific situation?

Finally, choose your Oscoo drive:

• ON2000PRO for Gen5 systems and professional work

• ON1000X for most gamers and creators

• ON1000PRO specifically for PS5

• ON900 for budget builds and older systems

FAQ: Common Questions About PCIe Generations

Q: Can I use a Gen5 SSD in a Gen4 slot?

Yes. PCIe is fully backward compatible. A Gen5 SSD in a Gen4 slot will simply run at Gen4 speeds. This is a valid future-proofing strategy if you plan to upgrade your motherboard within the drive's lifespan.

Q: Will I notice the difference between Gen4 and Gen5?

It depends entirely on your workload. For gaming, the difference is minimal (often less than 10%). For large file transfers like video projects or game installs, yes—you'll notice 30-40% faster transfers. For most daily tasks like web browsing and Office apps, no, you won't notice any difference.

Q: Does Gen5 run hotter?

Yes, significantly. Gen5 SSDs consume more power (10-12W vs 6-8W for Gen4) and generate more heat. Without proper cooling, they can reach 80°C and throttle aggressively. Proper cooling is essential.

Q: Is Gen5 worth it for gaming?

Generally, no. Games are mostly GPU-bound, not storage-bound. Once a game is loaded, SSD speed has minimal impact on frame rates. Level loading times might improve by a few seconds, but that's rarely worth the price premium for most gamers. Gen4 is the sweet spot for 95% of players.

Q: What about PS5? Can I use Gen5?

You CAN use Gen5 in PS5, but you SHOULDN'T. PS5 caps at PCIe Gen4 speeds, so Gen5 performance is wasted. You're literally paying for speed your PS5 cannot use. Get ON1000PRO instead—it meets all of Sony's requirements, has a built-in heatsink, and costs less.

Q: Will Gen5 make my computer feel faster overall?

If you're moving from a SATA SSD or hard drive, ANY NVMe drive will feel dramatically faster. But going from Gen4 to Gen5? The difference is noticeable only in specific scenarios like large file transfers. For general system responsiveness, don't expect a dramatic difference.

Q: How long until Gen6 comes out?

PCIe Gen6 specification was finalized in 2022, with consumer products expected around 2025-2026. It doubles bandwidth again to 64 GT/s. But the same question applies: will you actually need it?

Final Thoughts

The PCIe Gen4 vs Gen5 debate isn't about choosing the "better" technology—it's about choosing the right tool for your needs.

For the vast majority of users, PCIe Gen4 remains the sweet spot. ON1000X delivers 7,400 MB/s—more than enough for gaming, content creation, and daily use. It runs cooler, costs less, and works in virtually any modern system.

Gen5 (ON2000PRO) is for those who need absolutely maximum throughput: 8K video editors, 3D renderers, and enthusiasts building no-compromise systems. If you have a compatible motherboard, adequate cooling, and the budget, it's blisteringly fast.

The key is understanding YOUR use case. Buy for what you actually do, not for benchmarks you'll never see in real life.

About the Author:

This guide is based on Oscoo's internal testing and product specifications. For the most up-to-date pricing and availability, visit Oscoo Shop.

Related Articles:

NVMe vs SATA: Which SSD Should You Choose?

References:

1. Tom's Hardware - SSD Benchmarks Hierarchy 2025: Comprehensive testing of over 100 SSDs showing QD1 random I/O performance across PCIe Gen3, Gen4, and Gen5 drives.

Read the full benchmark hierarchy

2. Industry IOPS Testing Data (Tom's Hardware 2TB SSD Hierarchy 2025):

• Samsung 990 Pro (Gen4): 43,313 random IOPS (QD1)

• Crucial T700 (Gen5): 45,653 random IOPS (QD1)

• Adata Legend 970 Pro (Gen5): 54,217 random IOPS (QD1)

• Inland TN470 (Gen4): 50,679 random IOPS (QD1)

3. Data Sources and External References:

PCI Express - Wikipedia (PCIe 3.0/4.0/5.0 specifications)

Intel PCIe 4.0 and 5.0 Overview

AMD AM5 Platform PCIe 5.0 Support

Sony PS5 M.2 SSD Expansion Requirements (5,500 MB/s minimum)

CrystalDiskMark Testing Software

NVMe Thermal Throttling - ATP Electronics