2x NVMe M.2 SSD Raid0 (PCIe Gen.3 x4 + PCIe Gen.3 x2) question

insolito

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Hello, I just bought a AMD x470 motherboard (ROG STRIX X470-F GAMING) and I'm thinking of doing a raid0 of 2x NVMe M.2 SSD.

But from what I understood from the manual, i have two m.2 slots, one at PCIe Gen.3 x4 speed and another at PCIe Gen.3 x2 speed.

So, i have two doubts, (considering 2x equal PCIe Gen.3 NVMe SSD to mount a raid0):

#1: If i do a raid0 with these two SSD, they both will run at PCIe x2 speed?
#2: Even if it runs at "x4 + x2" or "x2 + x2", i will have a big performance loss compared to a raid0 "x4+x4"?

Thanks in advance!
 

insolito

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Even for better loadings? I know, Almost always one bigger drive is better than two smaller drives, but i cant afford for the bigger one right now, my plan was buy just one right now, and another from 2018 BF to make the raid0.
 

TJ Hooker

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RAIDing SSDs looks good in synthetic benchmarks for sequential read/write (often with high queue depth). You're never going to see those values in real life. A lot of regular consumer use is random I/O at low queue depth, which can actually be reduced with the SSDs in RAID0. So basically you're unlikely to see any performance improvement, possibly a tiny performance penalty, and you've now doubled the chance of losing all the data in the volume (if either of the SSDs fails).

I wouldn't recommend it.
 
IF, big IF, you get RAID working with 2 m.2 drives(good luck!), you will likely have DECREASED performance rather than increased. You won't find anyone on this forum that knows what they are talking about that will recommend doing a RAID for m.2 drives.
 

insolito

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Even if i dont mind about lose my data? (i can always download my games again, and i git my code, so, no data lost)

Last question:

Internet says: PCI Express 3.0's 8 GT/s bit rate effectively delivers 985 MB/s per lane, so maximum 1970MB/S at PCIe 3.0 x2 speed or maximum 3940MB/s (2x raid0) at PCIe 3.0 x2 speed , right?

I was aiming for 2x Corsair MP500 120GB, apparently they achieve 3000MB/s read and 2400MB/s write at max sequential read/write

This combined with my impossibility of buy a single 240GB SSD right now, maybe it is better to buy one now, and another on the BF to do this raid? Even at x2+x2, this raid technically is better than a single one drive, 3940MB/s vs ~3000MB/s