Crucial’s RealSSD C300 - The Perfect Test Candidate

The C300 is capable of pushing over 300MB/s in sequential reads. More than enough bandwidth to need 6Gbps SATA as well as expose limitations from PCIe 1.0 slots.

To test the C300 I’m using Highpoint’s RocketRAID 62X. This PCIe 2.0 x1 card has a Marvell 88SE9128 6Gbps controller on it.

What About P5x/H5x?

Unlike Intel’s X58, the P55 and H5x chipsets don’t have any PCIe 2.0 lanes. The LGA-1156 Core i7/5/3 processors have an on-die PCIe 2.0 controller with 16 lanes, but the actual chipset only has 8 PCIe 1.0 lanes. And as we’ve already established, a single PCIe 1.0 lane isn’t enough to feed a bandwidth hungry SSD on a 6Gbps SATA controller.

Gigabyte does the obvious thing and uses the PCIe 2.0 lanes coming off the CPU for USB 3 and 6Gbps SATA. This works perfectly if you are using integrated graphics. If you’re using discrete graphics, you have the option of giving it 8 lanes and have the remaining lanes used by USB 3/SATA 6Gbps. Most graphics cards are just fine running in x8 mode so it’s not too big of a loss. If you have two graphics cards installed however, Gigabyte’s P55 boards will switch to using the PCIe 1.0 lanes from the P55/H5x.

ASUS uses the same approach on its lower end P55 boards, but takes a different approach on its SLI/CF P55 boards. Enter the PLX PEX8608:

The PLX PEX8608 combines 4 PCIe x1 lanes and devotes their bandwidth to the Marvell 6Gbps controller. You lose some usable PCIe lanes from the PCH, but you get PCIe 2.0-like performance from the Marvell controller.

For most users, ASUS and Gigabyte’s varying approaches should deliver the same results. If you are running a multi-GPU setup), then ASUS’ approach makes more sense if you are planning on using a 6Gbps SATA drive. The downside is added cost and power consumed by the PLX chip (an extra ~1.5W).

The Primer: PCI Express 1.0 vs. 2.0 The Test Platforms
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  • assassin37 - Thursday, March 25, 2010 - link

    why isnt the x-58 gigabyte native 6gbs board on the write benchmarks?
  • blacksun1234 - Thursday, March 25, 2010 - link

    I would like to see HD Tune & HD Tach Average Read speed with Crucial HDD for each chipset. With this benchmark, AMD SB850 can beat Marvell's solution a lot!
  • Nickel020 - Thursday, March 25, 2010 - link

    There's a small error on page 4, that's an X58A-UD3R you've got there, not an X58-UD3R.

    Also, there seem to be two different Marvell 6G controllers, the 88SE9123 and the 88SE9128, what's difference between these two?
  • Nickel020 - Thursday, March 25, 2010 - link

    Finished reading, very interesteing results :)

    I find it really strange that P55 performs so poorly, I wonder whether it also performs poorly when used with SATA 3G SSDs, seeing as I'm just about two migrate my Vertex 60GB RAID 0 from P45&ICH10R to P55.
    Would be great if you could look into that as well, better storage performance would be a major reason to buy S1366 instead of S1156.
  • Etern205 - Thursday, March 25, 2010 - link

    If it's possible, mind adding the Asus U3S6 to your test (in a updated article) since that card uses a PCIe x4 interface.
    Thank You! :)

    The card">
  • nerdtalker - Thursday, March 25, 2010 - link

    That's an interesting card, since it appears from the photo to incorporate the 4x PCIe 1.0 PLX controller, or essentially the same on-motherboard solution ASUS was using.

    That seems like a much more interesting card to test.
  • 7Enigma - Thursday, March 25, 2010 - link

    Hi Anand,

    I have to admit that this particular article was a bit confusing for me. Probably because the test rigs are so similar in name I was going back and forth. My question is how does this article's results correlate to earlier boards (P45 for me in particular)? Am I understanding things correctly to assume that sticking a 6Gbps SATA card would actually be detrimental to performance in my rig if I was to get a new SSD in the coming months?

    Thanks for the informative article.
  • semo - Thursday, March 25, 2010 - link

    Hi Anand,

    On the 1st page, were you comparing Vertex LE performance on 890GX vs X58 or H55? And also do you have any comments on why it's random read is slower than the random write. AFAIK this is the only SSD with such characteristics.

  • Casper42 - Thursday, March 25, 2010 - link

    I noticed the same. Text says compared to X58 but both charts on page 1 say H55.
  • Exodite - Thursday, March 25, 2010 - link

    With the Thuban hexa-cores and 890X/FX boards in the pipeline AMD looks better and better for my next rig. After building a 790FX/PII 965BE rig for a friend, however, I were worried by the obviously poor disk performance even in comparison to my old P35/E6600 setup with an older HDD.

    I appreciate being kept up to date with this development as I see disk performance as the only major drawback of the platform at this point.

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