PCIe 6.0 will double the bandwidth of PCIe 5.0 to 256GB/s in 2021

Posted:
in Future Apple Hardware
Just a few months after standards for PCIe 5.0 were ratified, PCI-SIG has announced the specification for PCIe 6.0, a connection that will double the effective bandwidth from PCIe 5.0 to a maximum of 256 gigabytes per second.

The PCI 3.0 ports included in the modular Mac Pro
The PCI 3.0 ports included in the modular Mac Pro


The new standard is described as performing 64 "gigatransfers" per second, twice that of PCIe 5.0, four times that of PCIe 4.0, and eight times the capabilities of the commonly-used PCIe 3.0. The high 256 gigabytes per second of bandwidth also follows a similar multiplier, being eight times better than PCIe 3.0's 32 gigabytes per second.

The same multiplier over earlier versions also applies to the frequency, with PCIe 6.0 functioning at 64GHz. For reference, PCIe 4.0 and PCIe 3.0 operate at 16GHz and 8 GHz respectively.

To enable these higher speeds, PCI-SIG is also implementing PAM4 (Pulse Amplitude Modulation) signaling in PCIe 6.0 rather than the NRZ encoding scheme. Commonly used in networking, it uses low latency Forward Error Correction (FEC) with additional mechanisms to boost bandwidth efficiency.




Backwards compatibility with all previous PCIe generations is also pledged, as well as continuing to have a maximum lane count of 16, keeping it in line with other versions.

While the standard offers considerable bandwidth boosts over the existing PCIe 3.0 and slowly-arriving PCIe 4.0, there will still be quite a wait for it to become usable. Current expectations are for the specification to be published in 2021, with the first devices using it potentially arriving in 2022.

At the moment PCIe 3.0 is the prevalent technology, with PCI 4.0 hardware slowly arriving on the market. The ratification of PCIe 5.0 in January could lead to hardware using the standard arriving later in 2019, effectively outdating PCI 4.0 before it can become widely used.

The incoming PCIe 5.0 and the future PCIe 6.0 may be why Apple elected to stick with PCIe 3.0 in the new modular Mac Pro instead of using PCIe 4.0. As Apple is an early backer of technologies like USB, FireWire, and Thunderbolt, it is likely to use the standard in a future product, though the first signs of such usage may be years away, even beyond 2022.

Comments

  • Reply 1 of 16
    bvwjbvwj Posts: 8unconfirmed, member
    Apple stuck with PCIe 3.0 because Intel can't support PCIe 4.0.  AMD is the only processor supporting PCIe 4.0.  The question is why Apple sticks with Intel.
    caladanianSolimacpluspluschasmmichelb76entropysllamamainyehc
  • Reply 2 of 16
    wizard69wizard69 Posts: 12,828member
    bvwj said:
    Apple stuck with PCIe 3.0 because Intel can't support PCIe 4.0.  AMD is the only processor supporting PCIe 4.0.  The question is why Apple sticks with Intel.
    That is a very good question.  This especially after spending a year and a half with an AMD powered laptop running Linux.  I’m not sure if people realize how far AMD has come in the last 3 years.  In many ways they are a generation or two ahead of Intel now.  
  • Reply 3 of 16
    wizard69wizard69 Posts: 12,828member
    What amazes me here is how far we have come Since the advent of affordable computing.   I can remember irking on stage of the art 6502 powered CNC controllers with back planes running at less than 1MHZ. Somewhere around 980KHZ.   It is shocking how fast we can move data today.  
  • Reply 4 of 16
    sflocalsflocal Posts: 4,652member
    We're barely on PCI 4.0 (for AMD) and everyone else is using PCI 3.0 

    What the heck.  Why even bother with PCI5 then if 6.0 is already out there.  What's even more lame is that Intel can't get its act together on this.  Sure the new Mac Pro is hellaciously fast, but for that price it should have the latest and greatest.

    Intel really is a disappointment here.  They are about as innovative as Samsung is, and that's not good.
    SoliStrangeDayscoolfactormacseeker
  • Reply 5 of 16
    StrangeDaysStrangeDays Posts: 7,999member
    wizard69 said:
    bvwj said:
    Apple stuck with PCIe 3.0 because Intel can't support PCIe 4.0.  AMD is the only processor supporting PCIe 4.0.  The question is why Apple sticks with Intel.
    I’m not sure if people realize how far AMD has come in the last 3 years.  
    Funny, I've heard variations of that for the past 15 years. 
    lkruppcoolfactorSolichiallama
  • Reply 6 of 16
    mobirdmobird Posts: 186member
    Kinda sounds something like the 5G evolution, coming out with new standards when current standards have not met their full potential. And low and behold, Intel a barrier once again...

    coolfactor
  • Reply 7 of 16
    wizard69 said:
    bvwj said:
    Apple stuck with PCIe 3.0 because Intel can't support PCIe 4.0.  AMD is the only processor supporting PCIe 4.0.  The question is why Apple sticks with Intel.
    I’m not sure if people realize how far AMD has come in the last 3 years.  
    Funny, I've heard variations of that for the past 15 years. 
    I haven't. After their Opteron golden years, it was always a matter of "good enough" and "cheap enough". And they often weren't either.

    Now it's different. The current Zen+ chips are comparable or superior to Intel's offerings in many circumstances, and the new chips shipping 7/7 will beat Intel at just about everything.

    It's possible that Intel will retain the "gaming crown" with its most expensive desktop chip... by an insignificant amount. I wouldn't bet on it though. And for everything else, they will have no answer to AMD for a while.
    beowulfschmidt
  • Reply 8 of 16
    chasmchasm Posts: 1,597member
    sflocal said:
    We're barely on PCI 4.0 (for AMD) and everyone else is using PCI 3.0 

    What the heck.  Why even bother with PCI5 then if 6.0 is already out there.  What's even more lame is that Intel can't get its act together on this.  Sure the new Mac Pro is hellaciously fast, but for that price it should have the latest and greatest.

    Intel really is a disappointment here.  They are about as innovative as Samsung is, and that's not good.
    PCIe6 is not “out there.” At present, it exists only as a (likely) Word document with some specs on it. There will be many meetings and revisions. You should expect to see PCI6 in wide use towards the end of the next decade — it’s not coming next Tuesday, or two years from next Tuesday.

    PCIe3 was introduced in 2010 and has been the industry standard for the past seven years. PCIe4 was adopted by nobody but AMD and while it does double the bandwidth, it will never gain traction now because PCIe5, which is more likely to start appearing late next year and should carry us through most of the next decade, doubles things again. I expect PCIe5 will enjoy something just slightly less than the lifespan of PCIe3 (which is still on nearly every machine with slots being sold to this day, and will be for another year or two minimum).

    It is very likely that Intel was aware of the PCIe5 spec being close to ratification and opted to wait — sensibly IMO — for consumer demand to make it the new standard, rather than take the “fast obsolescence” path AMD chose. The market that actually needs PCIe5 (which, reminder, isn’t “out there” in the market yet either) is niche compared to the mainstream of computer users.

    As for next year’s Mac Pro buyers, I don’t think they’ll be complaining for a good few years to come, and by that time a Mac Pro with PCIe5 support is likely to be out or about to come out.
    edited June 18 beowulfschmidtdewmeauxio
  • Reply 9 of 16
    If that’s the case, PCIe7 specifications should be published by the end of this year. 🕶
  • Reply 10 of 16
    MacProMacPro Posts: 18,303member
    Ok, my new Mac Pro order is on hold.  PCle8 or nothing for me ...
    dewme
  • Reply 11 of 16
    dewmedewme Posts: 2,099member
    chasm said:
    sflocal said:
    We're barely on PCI 4.0 (for AMD) and everyone else is using PCI 3.0 

    What the heck.  Why even bother with PCI5 then if 6.0 is already out there.  What's even more lame is that Intel can't get its act together on this.  Sure the new Mac Pro is hellaciously fast, but for that price it should have the latest and greatest.

    Intel really is a disappointment here.  They are about as innovative as Samsung is, and that's not good.
    PCIe6 is not “out there.” At present, it exists only as a (likely) Word document with some specs on it. There will be many meetings and revisions. You should expect to see PCI6 in wide use towards the end of the next decade — it’s not coming next Tuesday, or two years from next Tuesday.

    PCIe3 was introduced in 2010 and has been the industry standard for the past seven years. PCIe4 was adopted by nobody but AMD and while it does double the bandwidth, it will never gain traction now because PCIe5, which is more likely to start appearing late next year and should carry us through most of the next decade, doubles things again. I expect PCIe5 will enjoy something just slightly less than the lifespan of PCIe3 (which is still on nearly every machine with slots being sold to this day, and will be for another year or two minimum).

    It is very likely that Intel was aware of the PCIe5 spec being close to ratification and opted to wait — sensibly IMO — for consumer demand to make it the new standard, rather than take the “fast obsolescence” path AMD chose. The market that actually needs PCIe5 (which, reminder, isn’t “out there” in the market yet either) is niche compared to the mainstream of computer users.

    As for next year’s Mac Pro buyers, I don’t think they’ll be complaining for a good few years to come, and by that time a Mac Pro with PCIe5 support is likely to be out or about to come out.
    Great post, especially regarding the "fast obsolescence" argument. Connectivity standards are a legal contract that explicitly define how products from different vendors must work together. There's zero room for error or misinterpretation. Getting it right is far more important than getting it sooner.
    llama
  • Reply 12 of 16
    deminsddeminsd Posts: 143member
    it's fun to chat about crazy speeds, but what (in reality) would your average person do with 256GB/s? I would need about 80 NVMe SSD's to saturate that amount of bandwidth. Let's talk about motherboards with 80 m.2 slots on them. :)
  • Reply 13 of 16
    I posted this in the Mac Pro thread before I noticed this article -- it seems more appropriate here:

    Source: [wccftech]

    Intel Xeon Cascade Lake does not support PCIe Gen4, and even the next 14nm++ generation, Cooper Lake (2020), also does not, at least not in samples currently shipping. Note that Cooper Lake has a new socket (LGA 4189) and platform, Whitley, which it shares with the first 10nm+ generation, Ice Lake (2020), which will support PCIe Gen4. The new socket and platform support eight channels of DDR4 memory.

    Both of the above currently exist -- we can assume Apple already knows what will happen with Xeon-W.

    After that is 10nm++ Sapphire Rapids in 2021 with PCIe Gen5 and DDR5 support, but that has another new platform, Eagle Stream. 

    So it's very possible that Apple will skip PCIe Gen4 -- it may depend on what Intel does with Xeon-W in relation to the above dual (both 14nm and 10nm) approach to Xeon-Scalable (a.k.a. Xeon-SP). If only Cooper Lake gets Xeon-W and it uses the new socket/platform, then Apple might choose to skip from PCIe Gen3 directly to PCIe Gen5 in late 2021 or 2022.

    Given Intel's troubles with the 10nm process, it seems unlikely that Ice Lake would be used for Xeon-W. But maybe they've solved the yield problems?
  • Reply 14 of 16
    melgrossmelgross Posts: 31,743member
    We,won’t be seeing PCI 5 until 2021. We won’t be seeing PCI 6 for a couple of years after that. It takes a couple of years after ratification for a new buss standards to reach manufacturing. Let’s not rush things here.

    here is a pretty thorough article on this from Anandtech:

    https://www.anandtech.com/show/14559/pci-express-bandwidth-to-be-doubled-again-pcie-60-announced-spec-to-land-in-2021

    read the very last paragraph.
    edited June 19
  • Reply 15 of 16
    ciacia Posts: 79member
    deminsd said:
    it's fun to chat about crazy speeds, but what (in reality) would your average person do with 256GB/s? I would need about 80 NVMe SSD's to saturate that amount of bandwidth. Let's talk about motherboards with 80 m.2 slots on them. :)
    I don't know why anyone needs more than 640k of RAM either!


    Looking back, if we'd stopped upping the specs every few years things would be a lot worse currently.   Yea all these crazy bandwidth numbers seem insanely useless, but so did needing gobs of RAM years ago and look where we are now.

    If you build it, they will come (and find a use for it).
  • Reply 16 of 16
    StrangeDaysStrangeDays Posts: 7,999member
    wizard69 said:
    bvwj said:
    Apple stuck with PCIe 3.0 because Intel can't support PCIe 4.0.  AMD is the only processor supporting PCIe 4.0.  The question is why Apple sticks with Intel.
    I’m not sure if people realize how far AMD has come in the last 3 years.  
    Funny, I've heard variations of that for the past 15 years. 
    I haven't. After their Opteron golden years, it was always a matter of "good enough" and "cheap enough". And they often weren't either.

    Now it's different. The current Zen+ chips are comparable or superior to Intel's offerings in many circumstances, and the new chips shipping 7/7 will beat Intel at just about everything.

    It's possible that Intel will retain the "gaming crown" with its most expensive desktop chip... by an insignificant amount. I wouldn't bet on it though. And for everything else, they will have no answer to AMD for a while.
    I’ve been building gaming PCs for over twenty years and AMDs have always been comin’ round the corner. 
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