Can any one explain more about PCI lanes

[pegot]

I’m about to order parts for my next build. I am considering one of the following two MB & CPU options (for now I will be using them with 3 GPU’s and water cooling).

BUILD OPTION 1
ASRock Z270 SuperCarrier LGA 1151
4 PCI 16 slots which run as 8/8/8/8
https://www.newegg.com/Product/Product. ... gnorebbr=1
Core i7-7700K 4.2 GHz
(16 PCI lanes)
https://www.newegg.com/Product/Product. ... 6819117726

BUILD OPTION 2
GIGABYTE GA-X99P-SLI LGA 2011-v3
4 PCI 16 slots which run as 8/16/8/8 (?)
https://www.newegg.com/Product/Product. ... 1N83UD9902
Core i7-6850K Broadwell-E 6-Core 3.6 GHz LGA
(40 PCI lanes)
https://www.newegg.com/Product/Product. ... 1UH4FM4685

I am just a little confused though about the MB & CPU sport of PCI lanes.

How does one tally up what components need how many lanes? If I will be using three GPU’s in this new build - does it matter if my CPU can only handle 16 lanes? What happens if your components need more lanes than are available from the CPU - do they run slower or just won’t run at all?

I do want this system for video editing as well, so a fast processor and the use of additional drive boxes for RAID need to figure in.

I’m also considering using these boards in a Hackintosh, though they might be a bit more difficult than some other combination of CPU and MB for that.

[FrankPooleFloating]

I really thought smicha or glimpse or someone of that ilk (more knowledgeable than myself) would have popped something in here for you chew on by now... maybe those dudes are on what Europeans call "holiday"...

You will certainly want no less than 28 lanes. If you are getting a quad-gpu ready mobo, let's assume that you might very well end up with a fourth in there. 28 Lanes would allow GPU 1 to run at 8x, and the other three at 4x, and then still be able to slap a m.2 SSD in at 4x.

It is my understanding that peeps with gpus on at least 4x do not have problems with loading/voxelization etc. And that things only really get noticeably slow to load when on 1x.

Remember that you get your number of lanes from your CPU. My i7 5820k has 28 lanes. In hindsight I kinda wish I would have gotten an i7 5960x, which would have given me 40 lanes... oh well.. my ws seems plenty fast. But it should be noted that there is AMD stuff coming with 128 lanes, and presumably Intel will too, and perhaps there will be a PCIe lane arms race between the two... I know, it's tough to make these decisions when new crap is right around the corner... But if I were building a second beast today, I think I would go X99 w/ 40 lanes and four used 980Ti hybrids. That beast would bring the best ROI, the best render-bang-for-the-buck, imho.

smicha really likes ASRock mobos. He does not like (hates?) Asus. I have a Gigabyte, and have had no problemos whatsoever.

[Notiusweb]

I would go 40 also!
The PC won't slow down if pushed over its limit, it just won't boot.

[pegot]

Thanks for the feed back guys. I was leaning towards the z270 because I think the x99 platform is starting to get a little long in the tooth, and of course the expense of a 40 lane CPU is much greater. And I really liked the features of the ASRock board. But I guess I will go for additional lanes as I do eventually want to populate the board with 4 GPU. I also have a Gigabyte MB now and it has served me pretty well these past 4 years. Spending lots of cash now knowing good stuff is probably around the corner is hard to chew on - but then that has always been the nature of system building I guess.

[FrankPooleFloating]

Hmmm... well, the ASRock Z270 SuperCarrier looks pretty effing nice... and daaaang, it has THREE m.2!!! I haven't looked at mobos lately... otay, maybe X99 is long in the tooth...

[rayrayato]

was also checking out the supercarrier - pretty sweet! nvidia live chat actually recommended that board to me when I asked them about which one to use for 4 GPU the other day.

[pegot]

I'm still on the fence. My thinking is that z270 is newer and therefore maybe a greater possible upgrade path when intel releases future CPUs (current i7 X are only for the latest 299 boards which I don't want). But the investment in x99 using a 6-Core Broadwell-E 6850K is not too much more and is a actually offset somewhat by the cheaper price of the Gigabyte MB. So I could always sacrifice that if the newer technology is truly compelling. I don't think an investment in x99 would be worth it with a higher priced 8 or 10 core Broadwell CPU though.