Can I run 2 x GPU and 2 x m.2 on Ryzen with x370

MikeRotch

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So I've been trying to research if I can do this. I don't think I am understanding how PCIe lanes work with CPU/Chipset

I don't intend to go SLI, but in my current setup I have a 750ti as a PhysX GPU (yes, I know, it's *mostly* useless but hey, it helped a lot in Arkham series) and a 1070 as main GPU. I also want to run 2 m.2 SSDs.

So can I do this and get all 4 devices to work off PCIe 3.0? Because from my understanding, I can't.

If I am running m.2 over PCIe 2.0, is that a bottleneck? Would I be better off saving my money and just getting a SATA SSD?

If I can't run this setup on x370m, can I do it on Intel?
 

Bandalo

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You've only got 20 lanes of PCIe 3.0 available with that CPU.

So your video cards will run 8x8, taking up 16 lanes. That leaves you 4 lanes for the m.2 SSD.

You might be able to tweak the 750ti down to only using 4 lanes though, and while that would technically free up some lanes, the MB doesn't allow them to be split that way, so you're kinda SOL.

It would work on an X99 board, you'd have either 28 or 40 lanes to use, and could run multiple video cards and m.2 SSDs.

That being said, there's very little performance benefit to running m.2 SSDs. I'd recommend running just one for your OS, games and programs, and a second SATA version for any other storage needs.
 

MikeRotch

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Thanks for the reply. So even on a Z270 chipset I wouldn't be able to do this huh? I would need to go x99...

Yah, I know m.2 doesn't have the great of a performance delta, but I have a current obsession of wanting to get rid of all SATA and SATA power cables.

Just thought of something, what if I used a M.2 -> PCIe adapter card for my 2nd m.2 drive and used the 2nd PCIe 3.0 slot... and put my 750tTi on the PCIe 2.0 slot?
 
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ReaperX22

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I Really find it hard to believe a 750 ti benefits a 1070 at all for physx.. what kind of numbers are we talking? TBH I think you'd find it easier to just drop the 750 Ti..

Not many boards come with 2 m.2 on x370, but you could use a PCIE add in card instead..

I'm in the same boat.. I wanna upgrade to a Z270i Strix Asus because it has 2 m.2 slots, replace my current 256gb/1tb samsung sata drives with a 960 Evo M.2 and 1TB Intel 600p. Removing the need for any sata cables lol. THE NEATNESS. Being in an ITX case makes me want this more too. x.x
 

Bandalo

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Thanks for the reply. So even on a Z270 chipset I wouldn't be able to do this huh? I would need to go x99...

Yah, I know m.2 doesn't have the great of a performance delta, but I have a current obsession of wanting to get rid of all SATA and SATA power cables.

Just thought of something, what if I used a M.2 -> PCIe adapter card for my 2nd m.2 drive and used the 2nd PCIe 3.0 slot... and put my 750tTi on the PCIe 2.0 slot?
PCI lanes are PCI lanes, so you can either send them to the M.2 slot, or send them to a x4 or x16 slot. You're going to need to dig deep into the manual for the SPECIFIC motherboard to answer those questions. On most boards, when you use the M.2 slot, you actually disable one of the x16 or x4 slots. So even if you technically have enough lanes to split things, the MB has to be built to allow that specific distribution of lanes.

I'd say ditch the PhysX-only card, as the benefit is probably barely measurable in real world performance. Even so, you'd be cutting into the lanes for your primary GPU by going with multiple M.2 SSDs.

I get saving some cables, but it's going to cost you quite a bit of cash to pull it off. (X99 + CPU is going to be heck of a lot more than a X370 + 1700)
 

Trimlock

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Yes you can and I believe the MSI Platinum and ASRock Fatal1ty boards are it right now.

The CPU HAS 16 lanes dedicated to GPUS. The boards support a max of 2x 16x PCIe 3.0 slots. The other four is for a dedicated ("turbo") m.2. Then it has 4 more connected to the chipset. The chipset has 8 PCIe 2.0 lanes and a m.2 can be connected to this. You won't be able to raid it and it will be much slower AND you will lose at least one of the PCIe slots with some SATA ports and possibly USB 3.0.

Edit: oops got carried away and said "yes" but that was mostly to if it will work. you want ALL on 3.0. I think the boards support 8x4x4 so if you get a board with a 4x slot you can make it work with an adapter.
 
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Bandalo

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Yes you can and I believe the MSI Platinum and ASRock Fatal1ty boards are it right now.

The CPU HAS 16 lanes dedicated to GPUS. The boards support a max of 2x 16x PCIe 3.0 slots. The other four is for a dedicated ("turbo") m.2. Then it has 4 more connected to the chipset. The chipset has 8 PCIe 2.0 lanes and a m.2 can be connected to this. You won't be able to raid it and it will be much slower AND you will lose at least one of the PCIe slots with some SATA ports and possibly USB 3.0.

Edit: oops got carried away and said "yes" but that was mostly to if it will work. you want ALL on 3.0. I think the boards support 8x4x4 so if you get a board with a 4x slot you can make it work with an adapter.
Negative. According to the manuals, there's a bunch of PCIe 2.0 1x slots, and 3 PCIe 3.0 16x slots. That 3rd slot is x4 only, and shares bandwidth with the m.2 slot. So it's either/or, not both. The other 2 slots share 16 lanes, so you get either 16x0 or 8x8.
 

MikeRotch

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Thanks for everyone's replies.

I did some testing with MSI Kombustor PhysX GPU test with and without the 750Ti.

Ran each scenario 4 times, and it turns out that I got lower scores with the 750Ti.

I had had 980Ti before and I ran the same test and I swear the 750Ti helped the score, or maybe it was when I had a GTX 960... don't remember anymore.

At least I'm still gonna have a use for my 750Ti: as a backup card if my GPU ever dies and I have to RMA. It's good for MAME and Telltale games, heh.
 

/dev/null

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I think you might be able to do this with the Asus X370-Pro

Manual is here

Have a look at page 16 (1-2) as well as page 8

PCIEx16_1 can have your main graphics card (running at PCIE 3.0 - x8)
PCIEx16_2 can have an adapter + m.2 (Running at PCIE 3.0 - x8 ,but only using 4 lanes. I think 8 lanes are still unavailable for other slots, however)
PCIEx16_3 can have your 750Ti (running PCIE 2.0 - x4. I think this disables pciex1_1 and pciex1_3)
m.2 #2 can go in the m.2 socket (I thinkt his will run at PCIE 3.0 - x4)

Edit: I wonder if the m.2 slot s pci-e 2.0 (~ 2GB/s max for 4 lanes) since x370 only provices 8 pci-e 2.0 and the cpu (presumably) is mapped to the first 2 pci-e slots.
 
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Trimlock

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Negative. According to the manuals, there's a bunch of PCIe 2.0 1x slots, and 3 PCIe 3.0 16x slots. That 3rd slot is x4 only, and shares bandwidth with the m.2 slot. So it's either/or, not both. The other 2 slots share 16 lanes, so you get either 16x0 or 8x8.
Yup looked it up after, not 8x4x4 either. Too bad.
 

ReaperX22

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Thanks for everyone's replies.

I did some testing with MSI Kombustor PhysX GPU test with and without the 750Ti.

Ran each scenario 4 times, and it turns out that I got lower scores with the 750Ti.

I had had 980Ti before and I ran the same test and I swear the 750Ti helped the score, or maybe it was when I had a GTX 960... don't remember anymore.

At least I'm still gonna have a use for my 750Ti: as a backup card if my GPU ever dies and I have to RMA. It's good for MAME and Telltale games, heh.
Well that more or less solves your problem :p. The GTX 750 Ti is quite a low end card. Good for indie games or E-Sports titles, but not much more anymore. On release it was a great entry card, though.
 

Reality

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try running the 750ti in one of the PCI-e slots that doesn't utilize the CPU? 370 boards can run additional PCI-e cards off the board chipset? maybe I misread that schematic
 

ole-m

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You've only got 20 lanes of PCIe 3.0 available with that CPU.

So your video cards will run 8x8, taking up 16 lanes. That leaves you 4 lanes for the m.2 SSD.

You might be able to tweak the 750ti down to only using 4 lanes though, and while that would technically free up some lanes, the MB doesn't allow them to be split that way, so you're kinda SOL.

It would work on an X99 board, you'd have either 28 or 40 lanes to use, and could run multiple video cards and m.2 SSDs.

That being said, there's very little performance benefit to running m.2 SSDs. I'd recommend running just one for your OS, games and programs, and a second SATA version for any other storage needs.
8X GPHX
8X GPHX
4X NVM
4X SouthBridge
4X out from Southbridge.

This does not bottle neck anything except 2nd M2 SSD which will still be 2x the speed of an Sata SSD. when M2 ssd's can give 4x performance over Sata.

Loading times in games is usually no better on M2 than Sata, and hardly better in many well designed games in HDD vs SSD - Modern vs Modern.

if you require raw throughput with SLI on Titan X or 1080TI caring about the last 1% of performance: X99 is the only option
if that 1% isn't worth 400$ Z270 and X370.
 

vegeta535

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Thanks for everyone's replies.

I did some testing with MSI Kombustor PhysX GPU test with and without the 750Ti.

Ran each scenario 4 times, and it turns out that I got lower scores with the 750Ti.

I had had 980Ti before and I ran the same test and I swear the 750Ti helped the score, or maybe it was when I had a GTX 960... don't remember anymore.

At least I'm still gonna have a use for my 750Ti: as a backup card if my GPU ever dies and I have to RMA. It's good for MAME and Telltale games, heh.
You probably got a lower score with the 750ti because it might be to slow at this point to keep up with a 1070. Like others said just ditch it all together.
 

Bandalo

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8X GPHX
8X GPHX
4X NVM
4X SouthBridge
4X out from Southbridge.

This does not bottle neck anything except 2nd M2 SSD which will still be 2x the speed of an Sata SSD. when M2 ssd's can give 4x performance over Sata.

Loading times in games is usually no better on M2 than Sata, and hardly better in many well designed games in HDD vs SSD - Modern vs Modern.

if you require raw throughput with SLI on Titan X or 1080TI caring about the last 1% of performance: X99 is the only option
if that 1% isn't worth 400$ Z270 and X370.
It depends entirely on what the motherboard will support. Some of them WILL let you run the m.2 in PCIe 2.0 mode, some will not. Same for the extra PCIe slots. Some are ONLY PCIe 3.0, and they can't be forced to 2.0 mode.

So technically it IS possible, but only if a MB manufacturer designs the board for that specific case.

And I did mention it's probably better to just run the SATA SSD rather than try some Franken-PC setup to run an M.2 in 2.0 mode. While the m.2 will be faster in benchmarks, in real world use the difference is almost undetectable. Especially if the OS is installed on the full-speed m.2 and the second SSD is just data.
 

Topweasel

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I am waiting semi patiently for a Taichi specifically because it runs both M.2 ports in PCIe (4x PCIe 3 for m.2-1 and 4x PCIe 2 for M.2-2) and only disables the third PCIe 16x channel leaving me the option for an xfire later.
 
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ole-m

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It depends entirely on what the motherboard will support. Some of them WILL let you run the m.2 in PCIe 2.0 mode, some will not. Same for the extra PCIe slots. Some are ONLY PCIe 3.0, and they can't be forced to 2.0 mode.

So technically it IS possible, but only if a MB manufacturer designs the board for that specific case.

And I did mention it's probably better to just run the SATA SSD rather than try some Franken-PC setup to run an M.2 in 2.0 mode. While the m.2 will be faster in benchmarks, in real world use the difference is almost undetectable. Especially if the OS is installed on the full-speed m.2 and the second SSD is just data.
yeah, the PCI-E Lane count is not a issue for 99%, amd have done their research!
However above is true with MB manufacturers, RGB is more important they think :)

Anyways, I've moved games over to the M2, Sata SSD and my baracuda pro 8 TB, and 50% of the time there is no load time difference at 3.6 allcore 1700, corsair MP500 vs Intel 250gb MH250A2 vs Baracuda Pro 8tb, some the gains are huge for SSD but not present with the M2.

Operating system and application Launch/ productivity is off the charts with M2
 
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There seems some mis info here.

2 lanes of pcie3 is 2GBps, way faster then sata (real max of ~550MBps), and yes, m2 pcie ssdS can use it - u can count on 2.5GBps from a good one.

in short - 2 x 2GBps ssdS are way superior to sata.

here is a nice clear graphic for a msi x370 mobo - see page 33

https://www.msi.com/Motherboard/support/X370-GAMING-PRO-CARBON-AC.html#down-manual

Not an issue here, but what excites me is raid0 for folks who can use it - video editors?

tests i see on raid0 pcie m.2 ssdS indicate an unimpressive 30%~ faster read, but 100% faster write (so writes are no longer the underdog~).

using the precious, but usually underutilised, am4 4 x pci3 lanes (4GBps) allowed for the 2 x m.2 slots on some moboS, u get a rip snorter device, which is hard to trust as a boot drive, but a way fast 4 GBps scratch file, even using lesser ssdS to samsungs top ones (anything that can write at max 2GBps can raid0 to 4GBps, the max bandwidth available on 4 lanes).

What may be exciting for power vega users to test the concept, is vegaS unlimited virtual vram a layered memory pool, using system memory and even storage to supplement gpu vram. Here we have raid storage that can saturate those precious 4 ryxen lanes lanes that bypass the chipset.

NB - i dont know for sure the mobo allows native raid on those two ports. Can anyone confirm?
 
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