17 R5, support for PCI Express 4.0 NVMe SSD

PCIe 4.0 is backward compatible with your PCIe 3 system.  

No, the warranty won't cover the installation, nor will Dell certify compatibility with a third-party drive.  While it should work, these are very new devices and until there's a base of users who've installed them, no one will know for sure.

No, you won't get the maximum throughput from a PCIe 4.0 drive in this system.  Right now no Intel platform has full 4.0 support, though some AMD Ryzen-based mainboards do.  

The sole reason at present for buying such a drive is future transfer to a 4.0 compliant system.  If that's your goal, the drive makes sense.  If it's to be kept for this system only, there's no point paying a premium for one at this point, because it won't be any faster than a less expensive 3.0 drive.

They're quoting the 32G/s as the drive to interface speed, which is the max for NVMe 3.0 X4.

The interface speed for the PCie 3 to the CPU is half that -- in other words, it's the PCI interface that is the limit, not the drive itself.

PCIe 4.0 (which appears headed for a short market life before 5.0 arrives in a year or so) doubles the speed of the interface vs. 3.0.

PCIe 4.0 NVMe drives right now are only really useful in AMD Ryzen systems.  Intel hasn't released a chipset at the desktop or notebook level with PCie 4.0 support (though that's supposed to happen fairly soon).

Hi @ejn63  appreciate your observations.

Hi @Alienware-Tammy  Alienware 17 R5 Setup and Specifications say that 17 R5 will support PCIe NVMe interface up to 32 Gbps. How can Alienware claim 17 R5 interface of 32 Gbps, if the Intel inside does not support 32 Gbps? 

The Parts & Upgrades for your Alienware 17 R5 is out of date. Dell's parochial use of SSD Class 10, 20, and 40 designations is not explained and does not include PCIe designations to assist with getting a PCIe NVMe SSD.  

It has nothing to do with software - it's a hardware limitation of the 3.0 PCIe specification.  And remember that 32G/s is a theoretical maximum -- which is never reached in practical operation.

Hi @ejn63  thank you for the clarification that it is the 17 R5 PCIe interface that limits the CPU performance. Evidently the 17 R5 Intel Chipset Device Software that enables the Intel hardware is not ready for and not designed to accommodate the 32Gbps SSD drive to PCI interface speed. This is a very curious revelation. 

Hi @ejn63  thank you for your in-depth observations which can be summarised that the Alienware 17 R5 Setup and Specifications webpage is not accurate and that Dell / Alienware's 2018 claim that 17 R5 is future proof, is not valid. Struggling with the concept of installing any version of PCIe NVMe SSD, because we will only be disappointed. 

No, that's not a summary;  it's your editorialization.

No SSD runs flat-out all the time.  Therefore, there will be a performance difference between an NVMe drive and a SATA drive even on a system that is PCIe 3.0.  And any NVMe 3.0X4 drive is well suited to this system.

Your original question asked about an NVMe 4.0 drive - which can run fast enough to require a PCIe 4.0 interface to the system, and which this Alienware (and all current Intel-platform notebook systems) will never support.  Once you hit that 5000 MBytes/sec that NVMe 4 drives are capable of, there are plenty of scenarios where the drive will outrun PCIe 3 bandwidth.

As for "future proof", no desktop or notebook is ever totally future-proof, since that's not a technically measurable term.  

If your plans are an upgrade to a future system that has PCIe 4 or 5 support, there may be value in buying such a drive now.  Your original question was about the compatibility between an NVMe 4 drive and an existing system.  It likely is compatible but will not perform faster than a standard NVMe 3.0X4 drive in your current system.  That means now - and in the future.

That's what I posted, stripped of any agenda-based editorialization.

Hi @Alienware-Tammy  when buying a new NVMe 1.4 SSD for 17 R5, are there any versions of the NVMe to be avoided?

You don't want a drive labeled NVMe 1.4 for a notebook - that's an Enterprise/Datacenter drive.

PCIe 4.0 is the client version, suitable for desktops and notebooks.

The two types of drive are optimized for completely different roles - 24/7 poweron for the datacenter drive vs. on/off cycles for notebook applications.

PCI Express specifications have revisions (5.0) and NVM Express specifications have versions (1.4).

NVMExpress.org says NVMe 1.4 specification addressed requests for flash storage across the data center, gaming applications, content creation, workstations, mobile, media creation and more.

Earlier it was advocated that 17 R5 supports PCIe 3.0 and now you don't want a drive labelled NVMe 1.4.

When looking to get a 17 R5 PCIe NVMe SSD, is it now advocated to get a PCIe 3.0 NVMe 1.0 and not a PCIe 3.0 NVMe 1.4?

The term NVMe 1.4 is usually applied to datacenter-class drives.  

The term for client drives is NVMe 4.0.

All I am pointing out is that there's a difference in terminology depending on the intended purpose of the drive.  Yes, the specification is the same.  No, the firmware and design are not.

Enterprise-class SSDs are designed for 24/7 operation in a climate-controlled server farm.  

Client SSDs are designed for use in desktops and notebooks, with extensive powerup/powerdown cycles and less than optimal cooling.

If you find a drive labeled NVMe 1.4 for end-user/client use, buy it.  Just note that most that are labeled this way are designed for server use, not for notebook or desktop use.

And going back to your original question:

Will the 17R5 support the 7 MBytes/s that the 980 Pro is capable of -- no, it won't.  You'll get just under 60% of that.

Right now (September 2020), the only systems with full PCIe 4.0 support are AMD Ryzen based.  They are the only systems that can take full advantage of the 980 Pro (and similar) drives.

You keep asking the exact same question:

"the actual PCIe 4.0 throughput will be an unknown improvement compared with the PCIe 3.0. Is this actual improved throughput worth spending more?"

Yes:  if you have an AMD Ryzen system with PCIe 4.0 support, or plan on keeping the drive for a future system that does.

No:  for your current Alienware notebook, which is PCIe 3.0.

That Samsung speed quote is 7000 megabytes/sec, or over 50 G/s, by the way.

As for the rest, long-term RW endurance and performance are very often counter-posing matters;  to gain one, you lose the other.