I don't understand the difference between 28 and 40 PCI lanes

[SuperCactus]

I don't get it? 40 seems a whole lot bigger than 28. In fact, it's 30% bigger. So will I get 30% more improvement?

 

the 5930k is expected to have 40 lanes and the 5820k will have only 28, and otherwise, they seem IDENTICAL!

And for 200$ more, why should I spend 50% more money if more PCI lanes doesn't improve performance?

 

In fact, what DO the PCI lanes do? I'm at complete loss for understanding. Does it increase FPS or something?

 

Please help me, I'm very very confused... I just want the haswell-e but 1000$ for the 5960X is so pointless for just 2 more cores, and the 600$ is originally how much money I have allotted for a cutting-edge CPU, but I'm thinking if the 400$ haswell-e with 28 lanes is almost always equal to the $600 haswell-e with 40 lanes, I might as well save my damn money.

 

So what does 40 PCI lanes have to offer over 28 PCI lanes?

[dizmo]

It's only theoretically helpful if you're running more than two video cards.

[dragoon20005]

the number of PCI-E lanes determines the possibility of installing expansion cards

 

4 way SLi will need all the PCI-E lanes your CPU can provide

 

 

which is why you see guys using X79 for 4 way SLi configs

[Askew]

PCIE lanes are how expansion cards communicate with the CPU, lanes are allocated to slots on the motherboard in addition to being routed to add in chips on the motherboard itself.

 

The more lanes, the more capacity for increased number and demand of expansion cards.

 

Watch this video, any more questions post in the thread.

 

[Aniallation]

So what does 40 PCI lanes have to offer over 28 PCI lanes?

 

Well... more lanes.

 

Let's say you had 16 PCIe lanes. If you ran two video cards, they would have to split the bandwidth, so each card runs at X8. If you had 32 PCIe lanes, both cards can run at full X16 speeds.

[Glenwing]

PCIe lane count isn't really a speed rating, it tells you the maximum bandwidth that is available for graphics cards' communication with the CPU.  Each lane of PCIe 3.0 has the capacity for about 1GB of data communication per second.  Having more lanes than you need won't increase performance, you just don't want to have so few that it starts restricting CPU/GPU intercommunication.  Generally an x8 lane of PCIe 3.0 has more than enough bandwidth for any gaming card, so 16 lanes for dual cards or 24 lanes for triple cards is fine.  In applications outside of gaming, such as when the GPU is being used to accelerate CPU computation for workstations and servers, there is a lot more communication between the CPU and GPU than in games, so 40 lanes might be helpful there.  The X99 platform is derived from Intel's server/workstation chips, so that's why they have so many lanes.

[SuperCactus]

Thanks everyone. This is the first time trying to build a PC.

 

With your help, I've decided that the 5820k with 28 PCI lanes might be better considering I only want a single GPU.

However I wonder if the 5930k will have better benchmarks than the 5820k.

 

On further note, does the number of PCI lanes limit the number of RAM slots? Why would a motherboard have 4 instead of 8?

[dragoon20005]

Thanks everyone. This is the first time trying to build a PC.

 

With your help, I've decided that the 5820k with 28 PCI lanes might be better considering I only want a single GPU.

However I wonder if the 5930k will have better benchmarks than the 5820k.

 

On further note, does the number of PCI lanes limit the number of RAM slots? Why would a motherboard have 4 instead of 8?

if the 5930k is like the 4930K

 

it could be the 6 core CPU where the 5820K will only be a quad core

 

both can run with 8 dimms but you still get only quad channel memory

[Glenwing]

Thanks everyone. This is the first time trying to build a PC.

 

With your help, I've decided that the 5820k with 28 PCI lanes might be better considering I only want a single GPU.

However I wonder if the 5930k will have better benchmarks than the 5820k.

 

On further note, does the number of PCI lanes limit the number of RAM slots? Why would a motherboard have 4 instead of 8?

 

No, the PCIe lanes and RAM aren't related.  Sometimes 4 RAM slots vs 8 might just be trying to hit a lower price point, but there's also physical space to consider; less RAM slots means potentially more room for beefier power delivery components that can help overclocking.  Most gamers on this platform aren't likely to need a lot of RAM, but a larger percentage will be interested in overclocking, so overall it's a good trade for some people.

[Sdot]

I was looking at the description on newegg for this cpu but didn't see anything about pci lanes.How am I able to tell how many lanes a cpu has?

[Real_PhillBert]

I was looking at the description on newegg for this cpu but didn't see anything about pci lanes.How am I able to tell how many lanes a cpu has?

 

http://www.anandtech.com/show/8426/the-intel-haswell-e-cpu-review-core-i7-5960x-i7-5930k-i7-5820k-tested

[ThomasD]

It is not just about graphics cards, it is about any sort of expansion card you might want to add - say a PCIE SSD card.  To get the full performance out of the card you will need unrestricted lanes for that card.

[Glenwing]

Please don't bump old threads.