Hi there! As an ardent technology follower, you‘re likely curious what real-world benefits this much-hyped PCIe 4.0 interface offers compared to PCIe 3.0 – not to mention whether it‘s worth upgrading your own system!
In this guide, we‘ll unpack everything you need to know around PCIe generational leaps:
- Key technical differences between PCIe 3.0 and PCIe 4.0
- Performance comparisons across various workloads
- Who stands to benefit most from adopting PCIe 4.0
- Future gazing at what PCIe 5.0 and 6.0 might enable
Let‘s get to it!
What Does PCIe Do? A Quick Refresher
In case you need a quick refresher, PCI Express (PCIe) is an interface standard used to connect critical components like your graphics card, SSD storage, WiFi card to the CPU.
Think of PCIe as the high-speed multilane highway facilitating blazing fast data transfers between these devices and your processor.
With every new PCIe generation, the connections get wider and the speed limit gets faster. More lanes, more bandwidth, more speed!
Transfer Speeds – PCIe 4.0 Leaves PCIe 3.0 In The Dust
The most publicized PCIe 4.0 upgrade focuses on raw transfer rate per lane. Here PCIe 4.0 doubles PCIe 3.0‘s capability – 16GT/s per lane versus 8GT/s.
But what does this actually mean? Well, PCIe 4.0 can shuttle a staggering 2 gigabytes of data per second per lane. Compared to 1GB on PCI 3.0.
That adds up quickly! A full 16 lane PCIe 4.0 slot now hits an astonishing 64GB/s top transfer speed.
PCIe 3.0 managed ‘only‘ 32GB/s for 16 lanes.
So if you‘re a hardcore gamer hungry for smoother frames, a content creator dealing with 8K video assets, or simply eager for ludicrously fast game installs – this 2X PCIe 4.0 bandwidth amplifies what you can achieve.
Latency – The Hidden Performance Killer
While we always drool over bandwidth specs in tech, latency is an equally critical metric!
You likely experience latency everyday as waiting for apps to load, games to respond to input, or video streams to buffer.
High latency cripples the user experience. Here again, PCIe 4.0 cuts latency a stunning 50% over PCIe 3.0:
| PCIe 4.0 | PCIe 3.0 | |
|---|---|---|
| Latency | 125 nanoseconds | 250 nanoseconds |
This means snappier response whenever your GPU talks to CPU, your SSD reads files, your WiFi connects to networks.
Who benefits most? Cutting edge gamers definitely appreciate the competitive edge lower latency brings in fast-paced titles.
High frequency traders literally make or lose fortunes if their algorithmic models run fractionally quicker. For them, PCIe 4.0 vs 3.0 latency delta is a massive win.
More Speed, More Power? Nope – PCIe 4.0 Doubles Efficiency
You would reasonably assume that doubling interface throughput requires more power. Amazingly, the opposite is true!
By intelligently managing power states, the PCIe 4.0 spec attained a 2X efficiency jump over PCIe 3.0.
| PCIe 4.0 | PCIe 3.0 | |
|---|---|---|
| Power Rating | 4W per GB transferred | 8W per GB transferred |
This means PCIe 4.0 consumes half the power PER GIGABYTE of data shuttled around your system!
For data centers moving mind-boggling quantities of data daily, improving power efficiency at scale is tremendously valuable to their bottom line.
Even for desktop users, the efficiency gains let your system stretch battery life longer and reduce electricity bills. And keep things cooler and quieter!
Backward Compatibility – Smooth Transition To PCIe 4.0
Jumping to a new interface standard often stresses compatibility. The good news? PCIe 4.0 was designed to interoperate with the existing PCIe 3.0 ecosystem.
On the hardware front:
- PCIe 4.0 devices happily function in PCIe 3.0 slots and motherboards. Albeit capped at PCIe 3.0‘s slower speeds.
- Conversely, most PCIe 3.0 hardware works fine when plugged into newer PCIe 4.0 systems! This protects your existing device investments.
On the software side, operating systems and applications don‘t generally need updates to leverage PCIe 4.0. Drivers and firmware may require updates to enable full functionality however – so check vendors release notes.
By building in backwards and forwards compatibility, PCIe 4.0 allows mixing and matching components during the transition period as your upgrade budget permits.
Comparing PCIe Generations – Benchmarks
We‘ve covered the technology upgrades PCIe 4.0 introduces over PCIe 3.0. Now let‘s quantify real-world performance differences across some benchmarks!
Sequential Read Speed
Comparing NVMe SSD drives highlights the effective bandwidth doubling:
| Drive | Max Seq. Read | Interface |
|---|---|---|
| Sabrent Rocket 4 Plus | 7000 MB/s | PCIe 4.0 |
| Samsung 970 EVO | 3500 MB/s | PCIe 3.0 |
For large file transfers, PCIe 4.0 simply crushes it – 2X faster reads than PCIe 3.0!
Random 4K Access
Low queue depth random IO mimics application responsiveness – again PCIe 4.0 rules:
| Drive | 4K QD1 Read | Interface |
|---|---|---|
| Corsair MP600 | 19,000 IOPS | PCIe 4.0 |
| WD Black SN750 | 12,000 IOPS | PCIe 3.0 |
Higher IOPS directly translates to snappier app load times. NVMe drives already dominate SATA SSDs here (not listed), and PCIe 4.0 stretches the lead further.
Game Load Times
Last but not least, game console benchmarks starkly showcase real world impact:
| Console | Game Load Time | Interface |
|---|---|---|
| Xbox Series X | 10 seconds | PCIe 4.0 |
| Xbox One X | 29 seconds | PCIe 3.0 |
By accelerating storage, PCIe 4.0 cuts game level loads by nearly 3X!
The numbers speak for themselves – for the ultimate gaming and computing performance, PCIe 4.0 represents a generational jump over PCIe 3.0 today.
Gazing Into The Future – PCIe 5.0 and PCIe 6.0
If you think PCIe 4.0 sounds outrageously fast already, well – the future holds even more radical speed jumps!
PCIe 5.0 ramps up the throughput dial yet again:
- 4X transfer rates per lane hit 32GT/s
- Support for mind-blowing slot bandwidths up to 256GB/s
- Refined signal encoding enhances data integrity
- More electrical power delivery headroom
Further down the road, PCIe 6.0 cranks the velocity limit even harder:
- Per lane throughput doubles again to 64GT/s
- Slot bandwidths scale to insane 1 Terabyte per second levels
This torrid pace of PCIe evolution will likely continue over the next decade!
The Verdict – Is PCIe 4.0 Worth It?
We‘ve covered a ton of ground comparing PCIe generations – by this point you‘re likely wondering whether jumping to PCIe 4.0 is worthwhile!
Here‘s some general guidance I‘d suggest to assess your own scenario:
- For gaming, absolutely – faster GPUs and storage pay off tangibly for smooth gameplay.
- Data science workloads also gain meaningfully from the extra bandwidth.
- Budget buyers can hold off for now until pricing drops further.
- If you already fully tax PCIe 3.0 limits – step up to PCIe 4.0 for more headroom.
- Regardless, choose components supporting backward and forward compatibility to future-proof systems.
While PCIe 3.0 still gets the job done perfectly well for many, the 2X speed boost PCIe 4.0 unlock represents a true generational technology leap.
For power users working on the bleeding edge, it‘s absolutely an essential enabler to maximize performance.
I hope breaking down PCIe 4.0 versus PCIe 3.0 in depth helped provide useful context! Let me know if any other questions come up.
