Thursday, October 26th 2017

PCI SIG Releases PCI-Express Gen 4.0 Specifications

The Peripheral Component Interconnect (PCI) special interest group (SIG) published the first official specification (version 1.0) of PCI-Express gen 4.0 bus. The specification's previous draft 0.9 was under technical review by members of the SIG. The new generation PCIe comes with double the bandwidth of PCI-Express gen 3.0, reduced latency, lane margining, and I/O virtualization capabilities. With the specification published, one can expect end-user products implementing it. PCI SIG has now turned its attention to the even newer PCI-Express gen 5.0 specification, which will be close to ready by mid-2019.

PCI-Express gen 4.0 comes with 16 GT/s bandwidth per-lane, per-direction, which is double that of gen 3.0. An M.2 NVMe drive implementing it, for example, will have 64 Gbps of interface bandwidth at its disposal. The SIG has also been steered toward lowering the latencies of the interconnect as HPC hardware designers are turning toward alternatives such as NVLink and InfinityFabric, not primarily for the bandwidth, but the lower latency. Lane margining is a new feature that allows hardware to maintain a uniform physical layer signal clarity across multiple PCIe devices connected to a common root complex. This is particularly important when you have multiple pieces of mission-critical hardware (such as RAID HBAs or HPC accelerators), and require uniform performance across them. The new specification also adds new I/O virtualization features that should prove useful in HPC and cloud computing.
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32 Comments on PCI SIG Releases PCI-Express Gen 4.0 Specifications

#1
Assimilator
btarunr said:
The new generation PCIe comes with double the bandwidth of PCI-Express gen 3.0, reduced latency, lane magining, and I/O virtualization capabilities.
Lane magining... man I've been waiting for this almost as long as I've been waiting for TPU to hire a proofreader who is actually literate.
Posted on Reply
#2
ShurikN
Assimilator said:
...I've been waiting for TPU to hire a proofreader who is actually literate.
Better not go to Guru3D then :D
Posted on Reply
#3
R-T-B
Assimilator said:
Lane magining... man I've been waiting for this almost as long as I've been waiting for TPU to hire a proofreader who is actually literate.
Using the word "literate" is a bit harsh, don't you think?

I know I made typoes. It's vs Its was my favorite. It doesn't mean I didn't try to fix them as fast as I could.
Posted on Reply
#4
Rehmanpa
How many watts will each slot output? I heard rumors awhile back about like 150w or something over 75w.

Also you guys shouldn't be so fixated on a typo; the world will continue.
Posted on Reply
#5
Chaitanya
Assimilator said:
Lane magining... man I've been waiting for this almost as long as I've been waiting for TPU to hire a proofreader who is actually literate.
Typos are part and parcel of news sites, it's better to take in gist of the story. You need to see kind of typos mainstream news outlet make while reporting on technology and compared to that these are quite few and far in between.
Posted on Reply
#6
cucker tarlson
Assimilator said:
Lane magining... man I've been waiting for this almost as long as I've been waiting for TPU to hire a proofreader who is actually literate.
'magine you had all of them lanes.....
Posted on Reply
#7
Aquinus
Resident Wat-man
btarunr said:
lane magining
I wonder what lane "magining" is. :p
Posted on Reply
#8
W1zzard
Fixed. And I thought you were discussing the actual technology
Posted on Reply
#9
Prima.Vera
W1zzard said:
Fixed. And I thought you were discussing the actual technology
People's priorities.... :ohwell:

Regarding this gen 4.0, does this mean we can finally have RAID 5 for M.2 SSD drives on non-HEDT platforms? ;)
Posted on Reply
#10
Assimilator
ShurikN said:
Better not go to Guru3D then :D
R-T-B said:
Using the word "literate" is a bit harsh, don't you think?
Of course it's harsh. It's harsh because I'm trying to make a point (also because I'm a dick but that should come as a surprise to nobody). That point is that even the most basic spellchecker (including the one built into any web browser) would have flagged "magining" as a non-word, which means that the only way it could have got into a published news post is if nobody bothered to do the absolute bare minimum of even looking at the wavy red underlines before pressing the button.

That might be acceptable for the barely-coherent English-Dutch pidgin that Guru3D's Hilbert excretes, but I've come to expect higher standards from TPU. I don't criticise because it makes me feel better or superior, I criticise because I care about the quality and professionalism of this site's content. And yeah, maybe public shaming isn't the best way to do it, but honestly it should never have happened in the first place.

R-T-B said:
I know I made typoes. It's vs Its was my favorite. It doesn't mean I didn't try to fix them as fast as I could.
It's vs its is semi-acceptable because a spellchecker won't (and can't) flag that case.
Posted on Reply
#11
Assimilator
As for the news itself, it seems to me that PCIe 4.0 and up are going to be more focused on enterprise than consumer features. Which IMO makes sense, because PCIe 3.0 has already been around for half a decade on desktop and isn't really showing any signs that it needs to be replaced.

What will be interesting is to see how (and when) Intel and AMD implement this on their CPU and motherboards. I'm expecting Intel to do their standard cheap-assery and offer half the number of lanes they currently do (so instead of 16 lanes of 3.0 from their mainstream CPUs, we'll get 8x 4.0 lanes, although I can hope that they will go with 12 lanes so that M.2 devices aren't bottlenecked through the chipset). I guess it will depend on the actual hardware requirements of PCIe 4.0 i.e. trace thickness.
Posted on Reply
#12
techy1
W1zzard said:
Fixed. And I thought you were discussing the actual technology
that was my exact reaction - I red the article and tought to my self: "damn, those are pretty big news, and there are lot of comments... I hope I will read them to make more insight when will 4.0 hit market and when/why 5.0"... and all comments are about meaningless typo :confused:
Posted on Reply
#13
lZKoce
I recently built a new PC, I am not buying an entirely new system in the next 5-6 years or so. If they manage to launch PCIe 4.0 into serial production and GPU's to actually utilize it by this period, then I will see it when I buy my new computer. Until then, I don't really get excited.

@Assimilator that burn man, that burn :D Reading the first comment for the news, I was like : ohhh snap :D
Posted on Reply
#14
R0H1T
Prima.Vera said:
People's priorities.... :ohwell:

Regarding this gen 4.0, does this mean we can finally have RAID 5 for M.2 SSD drives on non-HEDT platforms? ;)
Meh pcie 5.0 is coming soon enough, maybe it'll be mainstream by 2020 even, possibly for servers!
Posted on Reply
#15
Ferrum Master
Intel announced a pcie 4 capable SSD.

It means it current HEDT may live a short life...
Posted on Reply
#16
Th3pwn3r
Assimilator said:
Of course it's harsh. It's harsh because I'm trying to make a point (also because I'm a dick but that should come as a surprise to nobody). That point is that even the most basic spellchecker (including the one built into any web browser) would have flagged "magining" as a non-word, which means that the only way it could have got into a published news post is if nobody bothered to do the absolute bare minimum of even looking at the wavy red underlines before pressing the button.

That might be acceptable for the barely-coherent English-Dutch pidgin that Guru3D's Hilbert excretes, but I've come to expect higher standards from TPU. I don't criticise because it makes me feel better or superior, I criticise because I care about the quality and professionalism of this site's content. And yeah, maybe public shaming isn't the best way to do it, but honestly it should never have happened in the first place.



It's vs its is semi-acceptable because a spellchecker won't (and can't) flag that case.
There are errors in your post, correct them and try again.
Posted on Reply
#17
Aquinus
Resident Wat-man
Ferrum Master said:
It means it current HEDT may live a short life...
...if the only thing you care about is PCIe 4.0, sure.
Posted on Reply
#18
EarthDog
Aquinus said:
...if the only thing you care about is PCIe 4.0, sure.
And only if that PCIe 4 SSD is able to saturate PCIe 3.0 bandwidth in the first place would it be worth it. ;)



Also, to the writers and editors... may I suggest a browser plugin Grammarly. :)
Posted on Reply
#19
cadaveca
My name is Dave
Assimilator said:
It's vs its is semi-acceptable because a spellchecker won't (and can't) flag that case.
Complains about typos, but can't follow basic rules of not double posting. Hypocrite much?

@EarthDog I use Grammarly, and it doesn't pick everything up unfortunately, especially when there's tonnes of html/bbs coding. Spellcheckers in code don't work. :p

For example, that word, tonnes. That's plain English. But not American English. It's actual value is different, even (1.102 short tons US). Do you know how many spell checkers flag that as wrong? Nearly every one. If they can't get THAT right, they can get lots of other things wrong too.

AS to the news, I don't think that this could come soon enough. We need faster drives overall, and SATA just doesn't cut it these days. It would be nice if mechanical drives could be faster, but I don't know if that's even possible. :P
Posted on Reply
#20
EarthDog
Nothing picks up everything, but it would pick up quite a bit of the errors we see daily in these news articles. Also, don't use it on code...why would that work on code in the first place???

This place needs a gatekeeper BEFORE the news articles are published. Of the many that go up in a day, I would say a few have easily correctable errors which an editor should catch. Many of which Grammarly would catch. Again, it isn't perfect, but it's a lot better than nothing. :)

RE: tonnes/tons, etc.... your EIC needs to pick a writing style and have the team stick to it.
Posted on Reply
#21
Th3pwn3r
Hey, if you guys want to donate to hire an editor be my guest.
Posted on Reply
#22
Rehmanpa
EarthDog said:
Nothing picks up everything, but it would pick up quite a bit of the errors we see daily in these news articles. Also, don't use it on code...why would that work on code in the first place???

This place needs a gatekeeper BEFORE the news articles are published. Of the many that go up in a day, I would say a few have easily correctable errors which an editor should catch. Many of which Grammarly would catch. Again, it isn't perfect, but it's a lot better than nothing. :)

RE: tonnes/tons, etc.... your EIC needs to pick a writing style and have the team stick to it.
Are you going to keep being an ass or are you volunteering?
Give them a break, were lucky enough that they post news articles. A few typos isn't the end of the world, seriously. I promise that you won't die.
Posted on Reply
#23
Prima.Vera
I know I'm going to get a warning, but it's all worth it, however, seriously, some people in here are plain real hypocritical ASSHOLES. I saw native English speaking writers doing way worst mistakes than this on huge sites like CNN, BBC, etc.
Just give the guy a break for fk sake! How many foreign languages do you speak btw?? And I mean fluently. Jeeeeez!

--------------------------------------------------------------------------------------------------------------------------------------------------

Back on topic, Dave is right. I'm only looking to the PCIE bandwidth for the NVMe SSDs primary.
Seems that, for some reason (overhead), the current PCIE 3.0 x4 lines gets fully saturated on the latest Samsung 960 Pro drives. This can be easily seen when doing a RAID0 with 2 of those drives that caps at ~3.5GB/s for both reads/writes, when already a single drive can do 3.5GB/s for the reads.

Cannot wait for PCIE 4.0 motherboards.
Posted on Reply
#24
Rehmanpa
Prima.Vera said:

Back on topic, Dave is right. I'm only looking to the PCIE bandwidth for the NVMe SSDs primary.
Seems that, for some reason (overhead), the current PCIE 3.0 x4 lines gets fully saturated on the latest Samsung 960 Pro drives. This can be easily seen when doing a RAID0 with 2 of those drives that caps at ~3.5GB/s for both reads/writes, when already a single drive can do 3.5GB/s for the reads.
Cannot wait for PCIE 4.0 motherboards.
I wonder if AM4 and TR4 will be updated this year to have pcie 4.0 motherboards, and if intel is going to release z470 for that, claim they "needed to update it" :P
Posted on Reply
#25
EarthDog
Rehmanpa said:
Are you going to keep being an ass or are you volunteering?
Give them a break, were lucky enough that they post news articles. A few typos isn't the end of the world, seriously. I promise that you won't die.
You are right. Sorry, I know I am too critical at times. Do understand I was responding to Dave and not trying to pile on. Overall TPU does a good job here of volume news writing, there is no doubt. I get all of my quick hitters here. :)

If Prima is talking to me about language, I speak three relatively fluent. Jeez. :p

Perhaps when I am not volunteering as an editor/reviewer for my 7th year at one overclocking site and a paid freelancer at another, I will apply. :)
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