Two PCIe NVMe Cards and Two EVGA GeForce GTX 1080 Ti GPUs

hendrickhere

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Greetings community,

For my next build I want to use 2 x Samsung 960 EVO Series 250GB PCIe NVMe cards, and 2 x EVGA GeForce GTX 1080 Ti GPU's on a z370 Mobo (I‘m not sure which one yet – but it needs to have wifi). I also want to avoid any kind of RAID set-up because…I hardly know what is beyond the concept.

I want two NVE’s so that I can have the OS housed separately and have a few heavily moded games on the other. I’ll also need to keep enough SATA alive for another SSD and a HHD.

I’ve been looking around and I can’t find a definitive answer as to whether this will work or not? It doesn’t seem that crazy of an idea.

If it is possible, what are some things I should be sure to look out for? Are there any potential perils with this kind of set-up?

Thanks for your help!
 
Solution
It can 'work', absolutely.

2x NVMe drives require x4 PCIe lanes, each for max bandwidth/speed.
Dual Nvidia GPUs will require x8 connections each.
Any wifi, will likely run at x1

That's a total of 25 lanes.

The Z370 chipset provides 24PCIe lanes + 16 from the CPU.
The GPUs will get their x8 each from the CPU, with a full 24 lanes available via the chipset.

Take USB etc connectivity out of the equation, reducing the available lanes..... you'll still have more than enough for x4 + x4 + x1 (NVMe, NVMe and Wifi).


The only things to 'watch out' for, IMO, would be:

MB form-factor, typically 'included' Wifi is more prominent on mITX boards (although does exist on higher-end ATX boards too). If opting for mITX, definitely...

Barty1884

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It can 'work', absolutely.

2x NVMe drives require x4 PCIe lanes, each for max bandwidth/speed.
Dual Nvidia GPUs will require x8 connections each.
Any wifi, will likely run at x1

That's a total of 25 lanes.

The Z370 chipset provides 24PCIe lanes + 16 from the CPU.
The GPUs will get their x8 each from the CPU, with a full 24 lanes available via the chipset.

Take USB etc connectivity out of the equation, reducing the available lanes..... you'll still have more than enough for x4 + x4 + x1 (NVMe, NVMe and Wifi).


The only things to 'watch out' for, IMO, would be:

MB form-factor, typically 'included' Wifi is more prominent on mITX boards (although does exist on higher-end ATX boards too). If opting for mITX, definitely triple-check that there's 2x M.2 slots, supporting PCIe drives. Typically mITX boards will forgo one of the M.2 slots.

Don't focus on boards with 'included' Wifi. You're utilizing the same x1 config with an aftermarket Wifi card, so just ensure you have an available PCIe slot.

 
Solution
Your plan will work, but I have some thoughts:

1. Why not use a single 500gb m.2 Samsung 960 pcie for both the os and your apps?
It will be cheaper,perform a bit better and have longer endurance.
For a top end build, you might as well make that a m.2 Samsung 960 nvme PRO.
It is a touch faster.

2. You will usually get a stronger wifi signal with a discrete wifi card that includes a good antenna.

3. For sli GTX1080ti, plan on at least a 750w psu.

3. I would try a single card first and see how you do. dual gpu will win synthetic benchmarks, but your playing experience might be better with a single card. dual gpu is prone to stuttering and screen tearing. Increasingly, games do not support dual gpu.
You also need to pay attention to case cooling and separation of graphics card slots on your motherboard. The top card will run hotter.
 
If they are all going in PCI-Express Slots your second GPU might drop down to a 4x link disabling the ability to use SLI, this can possibly vary depending on the motherboard though, the other thing that is more likely is that both the NVMe SSD's will be running through the PCH which is limited to a PCI-Express 3.0 4x link, which means your 2x NVMe SSD's and all your SATA devices will be fighting for bandwidth other that small link, and 1 NVMe will pretty much saturate it. Software NVMe RAID 0 through the PCH is pointless as you wont gain anything, and NVMe RAID 0 will typically result in a performance drop due to increased latency from the software RAID overhead.
 

hendrickhere

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Thank you very much for your response!

I was planning on x2 NVMe cards to keep games separate from the OS. I thought this was best practice - is it not in your experience? Your point about m.2 Samsung 960 nvme PRO is interesting.

I have one 1080ti now and gaming at 4K and for most games this is sufficient. However, once GPU prices come back to MSRP I was hoping to pick up another to give extra push to the heavily modded games that I play (which work with sli). I do hear your point about one card being the best general solution.
 

Barty1884

Retired Moderator
geofelt is right - a single NVMe would be cheaper, and serve the same purpose (you could partition, if you really wanted to).

As for 4K - even with titles that "work" with SLI, it's rarely anywhere close to an value for money (ie 100% more cost, for ~30% more performance as an example). You might be better off waiting for the 11 series' top tier card for the better single-card performance*.

*Of course, if you can find a 1080TI for near MSRP in the relatively near future, and are comfortable with the gains vs the cost, then sure; go for it.
 

hendrickhere

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That sounds intimidating and potentially problematic. I envisioned everything (the GPUs and NVMes) all going through PCI (and not connected through SATA). So, do you think one superior NVMe would be a better solution for a build with two GPUs in SLI? Thanks!
 
It would only really be a problem if you are taxing both drives heavily at the same time, which I thought you might be doing at first cause I assumed a RAID Array. There are some advantages to having the OS and Games on different drives, as I have encountered some games where the patcher will literally pound my SSD with write and read requests to the point where my system was basically unresponsive for about an hour (This was on my C Drive), where i saw peak queue depths of 250+, I moved the game to another SSD so my system was useable when it patches, but 99.9% of games don't have this problem.
 

hendrickhere

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Thank you for your help! I was wishful thinking that prices would come down enough that I could eventually snag one for $500 ( sounds crazy now) which would totally warrant the price for a 30% increase. I think I will get one good NVMe, a solid z370 mobo that allows for sli, and then play the waiting game to see if I actually use it or not.