PCIe bottlenecks

[kpreg]

Hello everyone,

I have a few questions about PCIe bottle necking.

I've just received the first part of my new rig, the Maximus VII formula (Z97). My plan was to load it up with two Asus 970 STRIX cards. However, when I got my motherboard in yesterday, I noticed it came with a Bluetooth/WiFi card. I know my motherboard and processor (i7-4790k) both have 16 PCIe 3.0 lanes. My hope was to have each 970 running in 8x in 3.0, but it would really help if I could install that Wifi card without using up to much PCIe bandwidth. The Wifi card runs in 1x. So, is there any way to have the wifi card and both 970s running at the same time without creating a bottleneck?

Sorry if this sounds weird, but it's my first post. Any help would be appreciated.

[d33g33]

Hello everyone,

I have a few questions about PCIe bottle necking.

I've just received the first part of my new rig, the Maximus VII formula (Z97). My plan was to load it up with two Asus 970 STRIX cards. However, when I got my motherboard in yesterday, I noticed it came with a Bluetooth/WiFi card. I know my motherboard and processor (i7-4790k) both have 16 PCIe 3.0 lanes. My hope was to have each 970 running in 8x in 3.0, but it would really help if I could install that Wifi card without using up to much PCIe bandwidth. The Wifi card runs in 1x. So, is there any way to have the wifi card and both 970s running at the same time without creating a bottleneck?

Sorry if this sounds weird, but it's my first post. Any help would be appreciated.

There's no problem with this, populate the top two full PCI-E slots with your 970's and you could literally use any other PCI slot for the wifi/bluetooth without any performance hit.

 

Don't stress, you are A-OK

[typographie]

Someone may correct me, but I think Nvidia requires 8x/8x for dual SLI to operate. It may not even run in 8x/4x mode. So it's either working (and it's fine) or it's not.

[kpreg]

There's no problem with this, populate the top two full PCI-E slots with your 970's and you could literally use any other PCI slot for the wifi/bluetooth without any performance hit.

 

Don't stress, you are A-OK

Thanks, that's a complete relief. I was about to run an Ethernet cable across my house!

[d33g33]

Thanks, that's a complete relief. I was about to run an Ethernet cable across my house!

If you're able to and can do it neatly, i'd still run ethernet across your house, but that's me nothing beats physical connections

[d33g33]

Someone may correct me, but I think Nvidia requires 8x/8x for dual SLI to operate. It may not even run in 8x/4x mode. So it's either working (and it's fine) or it's not.

It runs in 8x/8x mode with SLI

[i_build_nanosuits]

Someone may correct me, but I think Nvidia requires 8x/8x for dual SLI to operate. It may not even run in 8x/4x mode. So it's either working (and it's fine) or it's not.

the X1 slots are handled by the chipset itself not the cpu...he could have all the x1 slots populated with stuff and still run dual gtx970 at 8x/8x which is perfectly fine

[kpreg]

.

the X1 slots are handled by the chipset itself not the cpu...he could have all the x1 slots populated with stuff and still run dual gtx970 at 8x/8x which is perfectly fine

Thanks for the help! I'll run the wifi card too.

[-rascal-]

the X1 slots are handled by the chipset itself not the cpu...he could have all the x1 slots populated with stuff and still run dual gtx970 at 8x/8x which is perfectly fine

 

^ Adding to this.

 

The Z97 chipset is capable of providing up to 8 PCI-E X1 lanes.

They are separate from the 16 PCI-E 3.0 lanes provided by the CPU itself.

 

Adding a WiFi card will NOT use one any of the 16 PCI-E 3.0 lanes.

You can run your WiFi card and SLi GTX 970's worry-free.

 

[han_han08]

thanks for the info guys.

learning a lot here

[typographie]

the X1 slots are handled by the chipset itself not the cpu...he could have all the x1 slots populated with stuff and still run dual gtx970 at 8x/8x which is perfectly fine

The Z97 chipset is capable of providing up to 8 PCI-E X1 lanes.

They are separate from the 16 PCI-E 3.0 lanes provided by the CPU itself.

 

Thanks, didn't know this.

 

Sorry if this is deviating from the topic a bit, but this doesn't seem to come up often so I'm going to sneak in a question: Adding an M.2 drive would subtract from those lanes available for the graphics, right?

[i_build_nanosuits]

Thanks, didn't know this.

 

Sorry if this is deviating from the topic a bit, but this doesn't seem to come up often so I'm going to sneak in a question: Adding an M.2 drive would subtract from those lanes available for the graphics, right?

on Z97 motherboards the M.2 slot  is wired to the chipset PCIe lanes (x2 at PCIe 2.0 transfer rates), so the lanes from the CPU will not be effected by the use of an M.2 device; you'll still have the full 16 PCIe 3.0 lanes available for graphics.

X99 provide X4 lanes through the chipset as well for the M.2

Many devices can already use 4 lanes and they would be constrained to various degree by an x2 M.2 slot...so it's pretty much a pointless feautre of the Z97 chipset already.

[FruitBasketSilex]

Ethernet cable would be better especially for online gaming, you would get better latencies, thus eliminating the possibility of lag

Not exactly the best way to describe it. You Dont eliminate lag, you get a better connection speed, and you Dont have to worry about interference.