Intel drops PCIe 4.0 support for Comet Lake Desktop

[Reytime]

Yikes! So you'd essentially buy a board for gen 11? A year, possibly 1 1/2 in advance? No?

 

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To add insult to injury, most motherboard manufacturers that are preparing to launch Socket 1200 models already added the necessary circuitry in order to support the PCIe 4.0 standard, and users who want to upgrade to gen 10 CPUs will have to pay for the integrated hardware even though it will effectively be deactivated with the upcoming Comet Lake CPUs.

 

https://www.notebookcheck.net/Intel-drops-PCIe-4-0-support-for-upcoming-Comet-Lake-desktop-CPUs-postpones-launch-to-April.451046.0.html

[Tristerin]

When trying to keep pricing competitive goes wrong.  

 

I assume this (from Intel) is to keep the associated mobo price down for another refresh and remain competitive to Intel fanboys.  Wonder if the mobo manufacturers or Intel eats this cost.

[Jurrunio]

Probably wont stop Nvidia from recommending Ryzen platform when their new GPUs support PCIe 4.0 now.

[SeriousDad69]

This doesn't really change anything. I can't see GPUs being bottlenecked by PCI-E 3.0 x16 for years to come and FPS snobs will always buy Intel as long as they maintain the slight FPS advantage(220 FPS instead of 200!!!..... At 3X power usage lol)

[Anomnomnomaly]

AMD went 4.0 for the prestige of being first... but I kinda think that Intel will bypass 4 for 5 as that's closer than most people think... It's not like the long gap between 3-4 when standards took so long to be agreed upon. 5 has already been agreed.

[2FA]

PCIe 4.0 is more important for servers than desktops thanks to NVMe and 40/100Gbps networking.

[DrMacintosh]

This is a great reason for Apple to switch to Threadripper/EPYC for the refresh of the Mac Pro. PCIE 4.0 would be a nice boost. 

[Arika]

by the time pcie 4 is actually being utilized intel will be on another platform, so yes, it makes sense to forgo support for comet lake.

 

i thought you people loved when companies removed useless things to lower costs

[Derangel]

14 minutes ago, Arika S said:

by the time pcie 4 is actually being utilized intel will be on another platform, so yes, it makes sense to forgo support for comet lake.

 

i thought you people loved when companies removed useless things to lower costs

If the rumor is right and mobo manus already have the circuitry for gen 4 built into their boards it’s not really going to decrease costs that much. Chipset might be a tad cheaper and it probably won’t require the fan that X570 does, but manus would likely have already planned for those costs.

[leadeater]

46 minutes ago, Arika S said:

i thought you people loved when companies removed useless things to lower costs

Yea but we also love pointless spec numbers that aren't even real world relevant, like throughput numbers on NVMe SSDs lol.

[Dylanc1500]

1 hour ago, Anomnomnomaly said:

AMD went 4.0 for the prestige of being first... but I kinda think that Intel will bypass 4 for 5 as that's closer than most people think... It's not like the long gap between 3-4 when standards took so long to be agreed upon. 5 has already been agreed.

They weren't even the first to implement PCIe 4.0, IBM was.

[TrigrH]

3 hours ago, Arika S said:

by the time pcie 4 is actually being utilized intel will be on another platform, so yes, it makes sense to forgo support for comet lake.

 

i thought you people loved when companies removed useless things to lower costs

Pcie 4 is only needed cos intel gimps the number of lanes on mainstream desktop. If Comet Lake has 32 CPU pcie 3.0 lanes then that would be great. Even Ryzen has 24 pcie CPU 4.0 lanes, which is awesome. 

[imreloadin]

This just gives Intel an excuse to create a new chipset 8 months from the initial release date.

[mr moose]

32 minutes ago, TrigrH said:

Pcie 4 is only needed cos intel gimps the number of lanes on mainstream desktop. If Comet Lake has 32 CPU pcie 3.0 lanes then that would be great. Even Ryzen has 24 pcie CPU 4.0 lanes, which is awesome. 

pcie4 isn't needed though.  it doesn't matter how many lanes AMD have versus Intel if 99% of users never run out of bandwidth.

[Reytime]

I agree how this will most likely not affect most of us, but it's kind of funny to think you have to buy PCIe 4 compatible motherboards to run a cpu that is not.

[Bombastinator]

Argh.  I was kinda counting on 4.0 support.  My current nebulous way forward was to buy the new intel with a fast 8/16 pcie 4.0, stick my 580 in it and wait for navi21/amphere to be revealed.  Maybe my ddr3 system will live to ddr5.  I’m kinda doubting it

 

way to push someone into AMD guys.

[TrigrH]

4 minutes ago, mr moose said:

pcie4 isn't needed though.  it doesn't matter how many lanes AMD have versus Intel if 99% of users never run out of bandwidth.

99% of users 1GPU

95% of intel boards: 16pcie wired to top slot

all CPU lanes gone.

 

Nvme drives work better when its not running through the chipset, and you cant do that with mainstream intel unless you reduce your GPU lanes on a Z series board.

[Bombastinator]

2 minutes ago, TrigrH said:

99% of users 1GPU

95% of intel boards: 16pcie wired to top slot

all CPU lanes gone.

 

Nvme drives work better when its not running through the chipset, and you cant do that with mainstream intel unless you reduce your GPU lanes on a Z series board.

Pcie3 wasn’t needed once upon a time either.  I’m glad I got a mobo that had it though.

[mr moose]

27 minutes ago, TrigrH said:

99% of users 1GPU

95% of intel boards: 16pcie wired to top slot

all CPU lanes gone.

 

Nvme drives work better when its not running through the chipset, and you cant do that with mainstream intel unless you reduce your GPU lanes on a Z series board.

https://www.gamersnexus.net/guides/2488-pci-e-3-x8-vs-x16-performance-impact-on-gpus

 

Which GPU needs so much that NVME is throttled in any way?

[TrigrH]

24 minutes ago, mr moose said:

https://www.gamersnexus.net/guides/2488-pci-e-3-x8-vs-x16-performance-impact-on-gpus

 

Which GPU needs so much that NVME is throttled in any way?

You cant always split your CPU PCIE lanes on all platforms, that feature is Z exclusive on intel. 

Chipset lanes also carry a latency penalty compared to using CPU lanes. Storage access times are more important than raw speed. Thats why I praise AMD for having spare CPU lanes assigned to m.2 and sata devices.

[Dabombinable]

So the DMI link won't even run at gen 4 speeds?

[porina]

3 hours ago, TrigrH said:

Even Ryzen has 24 pcie CPU 4.0 lanes, which is awesome. 

It's more useful to look at usable lanes, where AM4 gives the user 20, compared to Intel's 16.

 

2 hours ago, TrigrH said:

Nvme drives work better when its not running through the chipset, and you cant do that with mainstream intel unless you reduce your GPU lanes on a Z series board.

What use case do you have where this really makes a difference? That's not saying there isn't a difference, but where it really matters? When I got Optane, I did try connecting it on CPU and chipset lanes (on Intel platform) and there was a small detectable difference in benchmarks. Real world use, you'd never notice it.

 

 

 

So back to the original claim of this thread, anyone got a credible reference where Intel said they were doing PCIe 4.0 on the next desktop platform? Maybe I just missed it, but I don't recall ever hearing that.

 

Also the hardware differences between PCIe 3.0 and 4.0 may be overblown. We have AMD as the example for that. Have people already forgotten they also dropped 4.0 support... on older chipsets. It was working, but they were concerned about some edge cases where it might not be reliable and they killed support for it. Those older boards would not have had 4.0 in mind when they were made, but many would have worked if AMD hadn't pulled the plug. My understanding from that was that it wasn't so much you had to add more stuff to make 4.0 work, but that you had to make design considerations to ensure it worked. Signal integrity required more care.

 

[mr moose]

2 hours ago, TrigrH said:

You cant always split your CPU PCIE lanes on all platforms, that feature is Z exclusive on intel. 

Chipset lanes also carry a latency penalty compared to using CPU lanes. Storage access times are more important than raw speed. Thats why I praise AMD for having spare CPU lanes assigned to m.2 and sata devices.

You were trying to argue the need for More PCIe lanes based on GPU's taking all the bandwidth.   NVME always operates from the x4 on the PCH.   Given GPU's currently only suck down about half the bandwidth (maybe even much less) than the x16, see link I provided.  I fail to see how your claim we need pcie 4 is relevant.  If anything what people would want is to be able to link their NVME up tot he CPU PCIe lanes, but there is no evidence nor information out there that says that will net any real world benefit.

[TrigrH]

4 minutes ago, mr moose said:

You were trying to argue the need for More PCIe lanes based on GPU's taking all the bandwidth. 

Due to the way intel limits it yes.

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NVME always operates from the x4 on the PCH.

Not Ryzen and HEDT platforms.

Quote

   Given GPU's currently only suck down about half the bandwidth (maybe even much less) than the x16, see link I provided.  I fail to see how your claim we need pcie 4 is relevant.  If anything what people would want is to be able to link their NVME up tot he CPU PCIe lanes, but there is no evidence nor information out there that says that will net any real world benefit.

We don't need PCIE 4, I claimed we need more usable CPU lanes. When did I claim we need PCIe 4 I think you missed my point.

[Dabombinable]

5 hours ago, TrigrH said:

99% of users 1GPU

95% of intel boards: 16pcie wired to top slot

all CPU lanes gone.

 

Nvme drives work better when its not running through the chipset, and you cant do that with mainstream intel unless you reduce your GPU lanes on a Z series board.

Having the CPU lanes split between 2x of the x16 slots has further vindicated my choice to buy my Z97 Sabertooth. that being said, I'd love it if there were cards that (without RAID) let me run 2x NVME drives off the second slot. The storage SSD that I'll be getting latter on (some sort of 2TB QLC) will be gimped by the bottom x4 slot.

 

Or a riser that can split the top x16 to 4 PCIe x4 slots, since my GTX 1070 is stuck at x4 (no visible damage unlike my x8 GTX 970)  I'm currently only using 8 of the 16 lanes from the CPU. And with a case that has support for 10x PCIe cards...it'd extend the usefulness of my mobo a lot.