Question SSD OS upgrade questions

rcfant89

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I'm looking at the Samsung 970 evo plus, 980, 980 pro cards and it seems like the 980 is the worst of the three. My current M2 slots "dual m.2 connectors PCIe3.0 x4 dual mode". System specs are:

Gigabyte Z390 Aorus Pro Wifi (I think rev 1?)
I7 9700k
RTX 2070
16 GB Corsair Vengeance LPX DDR4 3200 MHz C16
500 GB 970 EVO currently in the m.2 slot

Most of the reviews and articles I've read say "go with the 970 evo plus because of the price difference and you won't get gen4 speeds", however the current price difference is only 15 bucks (159 vs 174) AND wouldn't I be able to use this:
https://www.amazon.com/Sabrent-NVMe-PCIe-Aluminum-EC-PCIE/dp/B084GDY2PW/ref=sr_1_16?crid=2Y049EUGDKDYN&keywords=PCIe+gen+4+expansion+card&qid=1668928084&sprefix=pcie+gen+4+expansion+car,aps,99&sr=8-16

and get the gen 4 speeds? If so, seems like a no brainer to go with the 980 pro. Is there anything I'm missing? I know there are a certain amount of lanes (I think 24?) but I don't know how many I'm using, how many are free, if there are any downsides to not using the dedicated m.2 slots and booting from PCIE/etc. Are there?

Might pick up another 2 pack of the RAM as well since it's only 54 bucks and my billion browser tabs typically have me at 80% utilization+ (surprisingly). Always thought 16 gigs was way too much but I'm not so sure anymore.

Thank you.
 

rcfant89

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And p.s. I'm not married to the Samsung drives, if there are better ones, that's cool. But I've been very happy with my 970 evo, it's just too small now. And I plan on using it in the M.2 slot as a secondary drive after the OS migration (if that matters for the PCI lanes). Thanks.
 
And p.s. I'm not married to the Samsung drives, if there are better ones, that's cool. But I've been very happy with my 970 evo, it's just too small now. And I plan on using it in the M.2 slot as a secondary drive after the OS migration (if that matters for the PCI lanes). Thanks.
Those adapters are "Wire to wire" they connect M.2 straight to PCIe just like in M.2 sockets on the MB. They can't change PCIe version, PCIe v4.o is downward compatible and will work at whatever lover version is.
 
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At that price difference no reason not to get the 980 pro, you can drop it in a 4.0 system later. Your heading says this is your OS drive and you don’t mention any other use, don’t worry about pcie 3.0 speeds for general OS and game use, have a look at this and see the difference is negligible for Windows.

View: https://youtu.be/4YoRKQy-UO4


As for adding RAM that may or may not work. Mixing kits even if the exact same model is not guaranteed to work without issue’s especially when try to run 4 DIMMS. It might work but you could run into problems. RAM is sold in matched kits for a reason.
 
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rcfant89

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Those adapters are "Wire to wire" they connect M.2 straight to PCIe just like in M.2 sockets on the MB. They can't change PCIe version, PCIe v4.o is downward compatible and will work at whatever lover version is.
Gotcha, so the PCIe x4 slot is the same as the M.2 slot (just a different form factor plug in)?

What if you used an expansion card at x8? The bandwidth chart says a PCIe 4.0 is twice as fast as a PCIe 3.0 on 4 lanes, 4GB/s vs 8 GB/s, but a PCIe 3.0 x8 is the same speed as a PCIe 4.0 x4. I do happen to have an x8 port open, since I only have the one GFX card in there. Would that drive be able to utilize 8 lanes and be around the same speed or would it only use 4 lanes? Thanks.
 

rcfant89

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As for adding RAM that may or may not work. Mixing kits even if the exact same model is not guaranteed to work without issue’s especially when try to run 4 DIMMS. It might work but you could run into problems. RAM is sold in matched kits for a reason.
Even if it's the exact same product order (as in, if you order a kit and then reorder the same exact item, I.e. CMK16GX4M2B3200C16)?

So when you order a ram kit, that's basically it, you gotta throw out the whole thing if you want to add more?
 
Gotcha, so the PCIe x4 slot is the same as the M.2 slot (just a different form factor plug in)?
What if you used an expansion card at x8? The bandwidth chart says a PCIe 4.0 is twice as fast as a PCIe 3.0 on 4 lanes, 4GB/s vs 8 GB/s, but a PCIe 3.0 x8 is the same speed as a PCIe 4.0 x4. I do happen to have an x8 port open, since I only have the one GFX card in there. Would that drive be able to utilize 8 lanes and be around the same speed or would it only use 4 lanes? Thanks.
Your system doesn't support PCIE 4.0.
Only PCIE 3.0 is supported
M.2 PCIE adapter (for single M.2 drive) uses x4 connection. It can not use x8 or x16 connection.
Doesn't matter, if it occupies entire x16 slot (only x4 connection is used).

So PCIE 4.0 M.2 drive in your system will work at PCIE 3.0 speeds. For PCIE 4.0 support you' d have to upgrade motherboard and cpu.
 
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Even if it's the exact same product order (as in, if you order a kit and then reorder the same exact item, I.e. CMK16GX4M2B3200C16)?

So when you order a ram kit, that's basically it, you gotta throw out the whole thing if you want to add more?
Yes even the same model number, they go to the effort to sell RAM as matched kits for a reason. It’s a topic that comes up frequently here, see the odd man out section here https://forums.tomshardware.com/faq/troubleshooting-problems-with-pc-memory-ram-and-xmp-profile-configurations.3398926/

I ran into the problem myself about 4-5 years ago trying to use 2 Corsair kits of the same model number. Just to be clear, I am not saying you will have problems, only that you may.
 
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rcfant89

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Your system doesn't support PCIE 4.0.
Only PCIE 3.0 is supported
Right

So PCIE 4.0 M.2 drive in your system will work at PCIE 3.0 speeds.
Right, and PCIe 3.0 x8 is the same speed as PCIe 4.0 x4.

So that was my question about using 8 lanes for a drive.

M.2 PCIE adapter (for single M.2 drive) uses x4 connection. It can not use x8 or x16 connection.
Doesn't matter, if it occupies entire x16 slot (only x4 connection is used).
So I read SABRENT NVMe M.2 SSD to PCIe X16/X8/X4 Card, but after seeing your comment and reading the fine print, it says: "Logical Interface / PCIe Lanes: X4." So you are right.

I guess the final question would be: Is there ANY PCIe card and/or drive combination that can use 8 lanes? I see that the linked ones above cannot. Are there ANY? Or is there an inherent limit that ALL NVME drives only use 4 lanes?

I realize there is probably not much/any discernable difference in my real world situation, I am just curious at this point. I'll probably end up going with the Gen 4 anyway, because the price difference is less than a penny per gig different and will maybe be a benefit with a future mobo upgrade, but still. Since I need to order the stuff anyway, why not ask?

Thank you for your help.
 

rcfant89

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Yes even the same model number, they go to the effort to sell RAM as matched kits for a reason. It’s a topic that comes up frequently here, see the odd man out section here https://forums.tomshardware.com/faq/troubleshooting-problems-with-pc-memory-ram-and-xmp-profile-configurations.3398926/

I ran into the problem myself about 4-5 years ago trying to use 2 Corsair kits of the same model number. Just to be clear, I am not saying you will have problems, only that you may.
Gotcha. I will skip the ram upgrade then. I guess I don't really need it. Not sure if I've ever hit 100% anyway. Thanks for (potentially) saving me a lot of headaches and some cash.
 
I guess the final question would be: Is there ANY PCIe card and/or drive combination that can use 8 lanes? I see that the linked ones above cannot. Are there ANY? Or is there an inherent limit that ALL NVME drives only use 4 lanes?
There are PCIE M.2 adapters with two M.2 slots on them.
Each M.2 drive still uses x4 connection.


https://shopee.pl/PCI-EX8-dual-disk-NVME-M.2-MKEY-SSD-RAID-array-expansion-adapter-motherboard-PCI-E-split-card-PE-i.547485389.11675361664
 

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