i9-9900K PCIe Lanes

[makinbacon21]

I'm sure everyone here has seen the ads and Amazon listing for the i9-9900k processor, and maybe a few of you already have it. If so, you've probably noticed the claim that the new chip has "up to 40 platform PCIe lanes." I jumped at that because my blasted i7-7700T on a Z270 MB can't cope with dual M.2 SSDs AND a 1080 Ti. This results in an obvious bottleneck. The claim to 40 lanes had me excited because a mainstream processor would finally be able to cope with my workload...then I looked at Intel's site. On their listing as well as on their "Ark" product index site, the processor is said to only have 16 PCIe lanes. This obviously wouldn't be any better than my current processor (besides the boost in performance from overclocking, better Turbo Boost, newer platform, etc.) for coping with my workload. Does anyone have the real number of lanes, or can explain the difference in numbers? I don't want to drop $530 on a CPU before knowing whether or not this is gonna fix my problem.

[Mira Yurizaki]

https://ark.intel.com/products/186605/Intel-Core-i9-9900K-Processor-16M-Cache-up-to-5-00-GHz-

 

There's only 16 lanes, just like any other mainstream chip. The "up to 40" is probably someone who doesn't know 24 or so come from the PCH.

[Jurrunio]

They are most likely seeing number from Z390 chipset.

 

At the end, all chipset lanes on Z370 get PCIe 3.0 x4 bandwidth in total anyway and I dont see Z390 changing that.

[makinbacon21]

Ok so if I want an x16 and two x4s I gotta get an X-series?

[Curufinwe_wins]

13 minutes ago, tmakin said:

I'm sure everyone here has seen the ads and Amazon listing for the i9-9900k processor, and maybe a few of you already have it. If so, you've probably noticed the claim that the new chip has "up to 40 platform PCIe lanes." I jumped at that because my blasted i7-7700T on a Z270 MB can't cope with dual M.2 SSDs AND a 1080 Ti. This results in an obvious bottleneck. The claim to 40 lanes had me excited because a mainstream processor would finally be able to cope with my workload...then I looked at Intel's site. On their listing as well as on their "Ark" product index site, the processor is said to only have 16 PCIe lanes. This obviously wouldn't be any better than my current processor (besides the boost in performance from overclocking, better Turbo Boost, newer platform, etc.) for coping with my workload. Does anyone have the real number of lanes, or can explain the difference in numbers? I don't want to drop $530 on a CPU before knowing whether or not this is gonna fix my problem.

umm the bottleneck you are experiencing now probably isn't related to pcie lanes. 8 lanes solo gpu is fine for the 1080ti. The issue is your ill-choice in a low power variant of the 7700k, which is notably worse as a cpu at keeping the 1080ti (and anything else) fed.

[makinbacon21]

that's what i originally thought--guess when i upgrade ill just get something like the i9-9900k. i didn't expect the 7700t to be THAT much of an issue--im at like 100% all the time. thks

[Mira Yurizaki]

4 minutes ago, tmakin said:

Ok so if I want an x16 and two x4s I gotta get an X-series?

Yes.

 

However keep in mind that the communication between the PCH and CPU is PCIe 3.0 x4. If your use case constantly has all of the connected PCH devices hammering CPU or RAM, then this is a legitimate concern. But if you're doing tasks between PCH devices, then I'm almost certain there's nothing to really worry about here. So basically, judging by what you want here, you want two NVMe drives. I'm guessing in a PCH system, transfer between the two drives should be at their full speed, assuming the motherboard manufacturer assigned four lanes to both.

 

EDIT: Also keep in mind the 16 lanes in the CPU are meant for graphics only. So if you plug in other things, you won't lose bandwidth against the graphics unless you plug something into another slot meant for graphics.

[Curufinwe_wins]

1 minute ago, tmakin said:

Ok so if I want an x16 and two x4s I gotta get an X-series?

Not necessarily tbh. dual x4 from the chipset is fine 99% of the time (unless using drives with real world performance individually in excess of 2GB/s, and even then... it won't be much of a hit).

 

Also 8x from the cpu is a miniscule hit in even gaming applications, and no hit at all in rendering.

 

But yes. X-series variants are the only ones past 16 cpu lanes (well 20 if you include the 4 forced to the chipset).

[Curufinwe_wins]

2 minutes ago, tmakin said:

that's what i originally thought--guess when i upgrade ill just get something like the i9-9900k. i didn't expect the 7700t to be THAT much of an issue--im at like 100% all the time. thks

Low power variants of these cpus are rarely if every worth it. In many workloads, with power gating, it even results in more total power consumption because the task takes so much longer to complete, and thus the computer is in a high power state for longer, even if it has lower power consumption at any given time.