New M.2 drive has very slow transfer speeds

MCAN

macrumors newbie
Original poster
Nov 16, 2018
4
6
Hello everyone,

Yesterday I installed an ADATA SX8200 M.2 drive via a PCIe adapter in my 2009 Mac Pro (flashed to 5,1) and have found the read/write speeds to be less than stellar.

For a drive that is supposed to get speeds of 3200 MB/s read and 1700MB/s write, I am getting lackluster speeds of about 196MB/s each.

The card is plugged into the second slot from the top.

Can anyone enlighten me as to why I am getting HDD speeds and how to get my top speeds? Does it have something to do with TRIM?

Thanks.
 

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smirk

macrumors 6502a
Jul 18, 2002
657
46
Orange County, CA
I'm still learning this stuff, so hopefully someone else chimes in, but the Mac Pro is PCIe 2.0, not 3.0, so right there your speeds are going to be way less than that 3200 MB/s number. The adapter card you have is a simple passthrough card, so you're limited to PCIe 2.0 with 4 lanes. The folks on here getting super fast numbers have more expensive cards that speak PCIe 3.0 to the SSD, and translate that into using more lanes of PCIe 2.0 to boost the speed.

I may be wrong on the details, but I think you can get the idea.

Also, have you updated your firmware to at least 138.0.0.0.0? I believe it contains something that boosted the PCI speed.

You should read post #1 of the NVMe thread on here.
 

MCAN

macrumors newbie
Original poster
Nov 16, 2018
4
6
I'm still learning this stuff, so hopefully someone else chimes in, but the Mac Pro is PCIe 2.0, not 3.0, so right there your speeds are going to be way less than that 3200 MB/s number. The adapter card you have is a simple passthrough card, so you're limited to PCIe 2.0 with 4 lanes. The folks on here getting super fast numbers have more expensive cards that speak PCIe 3.0 to the SSD, and translate that into using more lanes of PCIe 2.0 to boost the speed.

I may be wrong on the details, but I think you can get the idea.

Also, have you updated your firmware to at least 138.0.0.0.0? I believe it contains something that boosted the PCI speed.

You should read post #1 of the NVMe thread on here.

Thanks for the tips.

Where do I find firmware 138.0.0.0.0 (or higher)? What's the firmware for?
 

startergo

macrumors 65816
Sep 20, 2018
1,129
418
Hello everyone,

Yesterday I installed an ADATA SX8200 M.2 drive via a PCIe adapter in my 2009 Mac Pro (flashed to 5,1) and have found the read/write speeds to be less than stellar.

For a drive that is supposed to get speeds of 3200 MB/s read and 1700MB/s write, I am getting lackluster speeds of about 196MB/s each.

The card is plugged into the second slot from the top.

Can anyone enlighten me as to why I am getting HDD speeds and how to get my top speeds? Does it have something to do with TRIM?

Thanks.
Are you sure you have selected the right drive in blackmagic? the speed looks like the HDD speed
 

smirk

macrumors 6502a
Jul 18, 2002
657
46
Orange County, CA
Actually, I think I gave you incorrect information. It's true that the Mac Pro only supports PCIe 2.0, but according to other posts on here that should give you 1500MB/s with a pass-through card like you have. Also, I honestly don't understand what the significance of the 5 GT/s link speed that 138.0.0.0.0 brings means -- if it's only for video cards or also NVMe drives, and if it even means anything other than a number in a system report.

You do have your SSD plugged into slot two on that adapter, right?
 

MCAN

macrumors newbie
Original poster
Nov 16, 2018
4
6
Are you sure you have selected the right drive in blackmagic? the speed looks like the HDD speed

Positive.
[doublepost=1542404898][/doublepost]
You do have your SSD plugged into slot two on that adapter, right?
Yes.

I am updating to Mojave now as I understand the latest (and NVME supporting) boot firmware 140.0.0.0 is included.