[SOLVED] Full nvme speed support for a 4790k, Z97X-Gaming-5 build

[keithth]

I've got a machine I built a few years ago that is based around an 4.0ghz (OC'd to 4.2/Turbo 4.6) i7-4790k, Gigabyte Z97X-Gaming-5 mobo, 32GB DDR3 1866, 750TI graphics, and a few sata SSDs.

It's a general purpose computing machine but occasionally gets tasked with heavier things like running an occasional VM for FPGA programming. As part of trying to optimize the platform for that FPGA place-and-route process, I'm trying to add on a Samsung 970 Evo Plus, but I'm pretty sure my Gigabyte Z97X-G5 M.2 slot maxes out at 10Gb/s, which is only around 35% of the read speed of the SSD.

The only other lane-eating add-on I have is a 10gbps Mellanox NIC. This is for running to a NAS server for backups overnight. I was saturating the previous 100mbps connection, and needed more network bandwidth to speed up the backup.

Given my current configuration, can I do something like upgrade the mobo to a better chipset to be able to support this new nvme SSD?

I'm overall happy with the system and don't simply want to build another newer PC, or replace most of the components. Ideally, if I could buy a better mobo, keep the CPU, perhaps upgrade my RAM to something faster if the rest of the system can utilize it, then I'd be happy.

Thanks for any advice!

 

[SkyNetRising]

You can install PCIE M.2 adapter card.

 

[keithth]

You can install PCIE M.2 adapter card.

Thanks for replying.

I believe my two existing PCIE cards, the 750ti and the 10gbps card, are both configured to be 8x now by the bios. So 8,8,0.

So I'm assuming that the new configuration with that card would be 8,4,4 -- is that right? And PCIE 3.0 x4 would be support 3940MB/s, enough to cover the SSD.

When I first installed my 10gbps card, I had it in a slot I'd intend on using for the SSD, and saw a drop in performance.....so I guess I'll be interested to see what happens.

That 10gbps card is a PCIE 2.0 x8 card.

Thanks

 

[SkyNetRising]

1st and 2nd PCIE x16 slots share bandwidth. With both of them populated, they run at PCIE 3.0 x8/x8 mode.
3rd PCIE x16 slot shares bandwidth with PCIE x1 slots on motherboard. With 3rd PCIE x16 slot populated it will run at PCIE 2.0 4x ( x1 slots will get disabled).

To run M.2 on PCIE adapter at full speed, it needs to be placed in 1st or 2nd PCIE x16 slots. You can put graphics card in the 3rd PCIE x16 slot.

 

[keithth]

1st and 2nd PCIE x16 slots share bandwidth. With both of them populated, they run at PCIE 3.0 x8/x8 mode.
3rd PCIE x16 slot shares bandwidth with PCIE x1 slots on motherboard. With 3rd PCIE x16 slot populated it will run at PCIE 2.0 4x ( x1 slots will get disabled).

To run M.2 on PCIE adapter at full speed, it needs to be placed in 1st or 2nd PCIE x16 slots. You can put graphics card in the 3rd PCIE x16 slot.

Thanks for the explanation. It took me a minute staring at the block diagram of the motherboard to understand what was going on. I was originally missing why that third slot wouldn't be sufficient, and that's because that third slot connects to the PCH which in turn uses DMI 2.0 to talk with the CPU. DMI 2.0 x4, like PCIE 2.0 x4, is limited to 2GB/s in each direction, falling short of the 3500+/- capability of the SSD. This explains why previously using the 10gbps NIC in that slot yielded such poor performance.

For other people researching this, my mobo manual here helped, see PDF page 8. I also found the wiki page on DMI interesting, and the subsequent reference to Intel's datasheet on the CPU, especially the DMI spec overview on PDF page 14.

Thanks again SkyNetRising!

 

[keithth]

So it turns out that my 750ti card is not going to fit in the bottom PCH slot, due to the fact that the PCIE connector is almost at the edge of the motherboard, and given the fact that the Gigabyte 750ti is a "double-wide" --- that the gpu-mounted-fans physically contact the supply, and it's impossible to insert the card. The card ends up being "too high" for the slot by 1/2 inch to 1 inch.

A fairly short riser cable would solve the pcie-interface distance mismatch, but then the display connectors also don't line up in the slots properly. One problem almost begets the other.

Slot 1: 10gbps network card. Which has to be in 1 or 2 to get full speed.
Slot 2: Intended on putting 970 evo plus via an x4 adapter card, which also needs to be in 1 or 2 to get full speed.
Slot 3: Intended on putting Gigabyte 750ti graphics card, but doesn't fit. The reduced PCIE bandwidth should not affect me, based on what I read.

I suppose either a slightly larger(taller) microatx case with more room between the mobo and power supply might work. Or a different graphics card.

Help!@#

 

[SkyNetRising]

Does any of your software require use discrete graphics card?
If not, then you could just use CPU integrated graphics.

Or change graphics card to GT 1030 (single slot model)
http://www.palit.com/palit/vgapro.php?id=2883

 

[keithth]

Not really. I occasionally play some older Steam games....think things like "Need for Speed" or similar. Nothing cutting edge, and I couldn't care less about fps. Of course it kinda sucks to have to lose an existing capability to gain another..... I would almost definitely benefit from the SSD speed up.

Maybe I'll try the integrated graphics and see exactly how good/bad they are!

Adding more than two monitors and/or 4k might be nice for in the future....and having the capacity to run a new-ish game might be nice for the random time I need it....

But thanks.