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PCI-E SSD's and mSata's: Same advantages?

I see some serious modern systems are using SSD's with a PCI-E connection as its faster than the traditional Sata connection. But what about mSata drives that use a PCI-E mini connection? Same speed as PCI-E? And at what speed do they need? Would a x1 slot work OK? Or do they need the full speed x16 slot? I realize that there are many grades of drives.
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  1. Best answer
    mSATA drives run over SATA, not PCIe. While the connector is physically identical to mPCIe, it's not transferring data over PCIe. mSATA SSDs should perform identically to SATA versions, unless corners have been cut to shrink it.

    However, the new M.2 format does use multiple PCIe3.0 lanes to transfer data.

    Generally, a single lane of PCIe3.0 is quite hard to bottleneck, as there's up to 1GB/s each way per lane.
  2. The real question is how many pcie lanes do you have?
    For example, socket 1155 and 1150 only have 16 lanes total and most gamers would prefer to reserve those for their gpu's since even taking 1 lane away drops them to x8 mode.

    As for sata speeds, sas is already up to 12gb/s, sata will follow soon would be my guess. In the mean time thou, a pcie lane is 500 MB/s and a sata port is about 575MB/s. At minimum a modern ssd would need an x4 slot since there are no x2 slots. Personally I don't see pcie ssd's as a good venture.

    I think you are confused about msata and mini pcie.Though they use the same connector they are electrically different. Some manufacturers use a built in switch to support both functions on the 1 connector allowing you either amini pcie card or msata drive. Msata is being replaced by M.2
  3. There are x2 slots, but they aren't implemented much IIRC.

    I thought that mPCIe and mSATA just used different pins. If it uses one set, it's SATA, and another, it's PCIe.

    Chipsets generally have PCIe lanes off them.
  4. These are good explanations. Thank you.
    So how close is the newer M.2Sata connection to PCI-E now?
    I see mSata or something like it being so useful, especially with small storage size as you don't need a huge space for your OS and most programs that are resource demanding.
  5. M.2 is a form factor with a whole pile of different connection options. It uses SATA Express, which is a standardised means of moving SATA over PCIe lanes (M.2 allows up to four). You can, however, put a whole pile of different types of traffic through it, including legacy SATA, USB3.0, plus others like UART serial, I2C, and the Wikipedia article seems to imply that you can also put Displayport lanes down it.

    There's 1TB mSATA SSDs out now; I imagine there will be similar sizes once M.2 kicks off.
  6. Someone Somewhere said:
    M.2 is a form factor with a whole pile of different connection options. It uses SATA Express, which is a standardised means of moving SATA over PCIe lanes (M.2 allows up to four). You can, however, put a whole pile of different types of traffic through it, including legacy SATA, USB3.0, plus others like UART serial, I2C, and the Wikipedia article seems to imply that you can also put Displayport lanes down it.

    There's 1TB mSATA SSDs out now; I imagine there will be similar sizes once M.2 kicks off.


    Keep in mind that most M.2 SSDs will fall in two categories. Some M.2 form factored SSDs are simply drives which operate over SATA. If the M.2 edge connector is wired into a/the SATA controller, any M.2 SSD which operates over a SATA physical layer will work. Then there are some native PCIe SSDs in M.2 forms. These drives have controllers which interface directly over PCIe in x1,x2, or x4 formats.

    Even if you currently have a solution which supports M.2, the a M.2 SATA SSD won't work if that SATA slot isn't wired into the motherboard's controller. That wouldn't be terrible, the native PCIe drives are much faster. You just can't quite buy one of those through most retailers yet. That'll change pretty soon though.

    FYI a single PCIe lane SSD wouldn't be fantastic. It's partly why 3rd party SATA controllers aren't as fast as native ports; they're typically attached over a single PCIe lane.


    Regards,
    Christopher Ryan
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