MP 1,1-5,1 NVME speed on Mac 5,1

[changareth]

I bought a WD BLACK SN750 2 TB into a Wolftech Pulsecard running mojave and these are the readings I’m getting. Is it normal? I get 1102mb/s sometimes tops. Was hoping to get 14xx writing like I see with evo 970 but I couldn’t get that in my country coz it’s out of date. Is this just to do with my the WD ssd? And how come there are 3 criteria in the test are greyed out?

 

[tsialex]

View attachment 2007410

I bought a WD BLACK SN750 2 TB into a Wolftech Pulsecard running mojave and these are the readings I’m getting. Is it normal? I get 1102mb/s sometimes tops. Was hoping to get 14xx writing like I see with evo 970 but I couldn’t get that in my country coz it’s out of date. Is this just to do with my the WD ssd? And how come there are 3 criteria in the test are greyed out?

You blade is correctly installed, x4 with 5GT/s. The write speed is always inferior than the read speed after the controller write cache is full, specially with non high-end blades.

Your speeds seems average for this blade, when installed in a MacPro5,1 PCIe v2.0 slot - you can get it faster using a PCIe v3.0 switched adapter, see the PCIe blades stickie first post for more info.

 

[changareth]

You blade is correctly installed, x4 with 5GT/s. The write speed is always inferior than the read speed after the controller write cache is full, specially with non high-end blades.

Your speeds seems average for this blade, when installed in a MacPro5,1 PCIe v2.0 slot - you can get it faster using a PCIe v3.0 switched adapter, see the PCIe blades stickie first post for more info.

Oh thx! So getting a better blade would improve it?

 

[tsialex]

Oh thx! So getting a better blade would improve it?

A high end blade like 970 PRO 1TB will get write speeds around the practical throughput/real life limit of the PCIe v2.0 x4 slot, ~1450MB/s.

PCIe SSDs - NVMe & AHCI

This is a general info thread for blade SSDs that can be used in the Mac Pro. This is a WikiPost so anyone with the proper credentials may edit it. NVMe SSDs can be used as a boot drive in the MP5,1 and MP6,1 with the latest firmware installed (beginning with version 140.0.0.0.0 for MP5,1 and...

forums.macrumors.com

If you buy a cheap PCIe switched adapter, like the StarTech PEX8M2E2 for around $175, you will double the SN750 throughput - if your slot-2 is free.

https://forums.macrumors.com/threads/pcie-ssds-nvme-ahci.2146725/post-31092456

 

[changareth]

You blade is correctly installed, x4 with 5GT/s. The write speed is always inferior than the read speed after the controller write cache is full, specially with non high-end blades.

Your speeds seems average for this blade, when installed in a MacPro5,1 PCIe v2.0 slot - you can get it faster using a PCIe v3.0 switched adapter, see the PCIe blades stickie first post for more info.

Oh thx! So getting a better blade would improve it?

A high end blade like 970 PRO 1TB will get write speeds around the practical throughput/real life limit of the PCIe v2.0 x4 slot, ~1450MB/s.

PCIe SSDs - NVMe & AHCI

This is a general info thread for blade SSDs that can be used in the Mac Pro. This is a WikiPost so anyone with the proper credentials may edit it. NVMe SSDs can be used as a boot drive in the MP5,1 and MP6,1 with the latest firmware installed (beginning with version 140.0.0.0.0 for MP5,1 and...

forums.macrumors.com

If you buy a cheap PCIe switched adapter, like the StarTech PEX8M2E2 for around $175, you will double the SN750 throughput - if your slot-2 is free.

https://forums.macrumors.com/threads/pcie-ssds-nvme-ahci.2146725/post-31092456

so I have to run a adapter and run raid0 u mean? Coz I’m using my nvme now as my main boot drive. If I just have a single blade I can’t push anything further than what I have unless I get a better one like 970 I suppose yeah?

 

[tsialex]

so I have to run a adapter and run raid0 u mean?

Nope, with just one blade the throughput will double since the switch converts wide/slow PCIe v2.0 x8 or x16 to fast/narrow PCIe v3.0 x4.

If I just have a single blade I can’t push anything further than what I have unless I get a better one like 970 I suppose yeah?

Without a PCIe switched adapter, you will be always limited to the ~1450MB/s practical limit of a x4 PCIe v2.0 slot. All M.2 devices are x4.

Please read the first post of the PCIe thread and use the search in that thread to know more about things that you are in doubt, every question possible was answered that over the years.

RAID is not even supported with APFS for boot disks.

 

[changareth]

Nope, with just one blade the throughput will double since the switch converts wide/slow PCIe v2.0 x8 or x16 to fast/narrow PCIe v3.0 x4.

Without a PCIe switched adapter, you will be always limited to the ~1450MB/s practical limit of a x4 PCIe v2.0 slot. All M.2 devices are x4.

Please read the first post of the PCIe thread and use the search in that thread to know more about things that you are in doubt, every question possible was answered that over the years.

RAID is not even supported with APFS for boot disks.

Awesome thanks. I shall get that adapter then. Yeah I did go thru that post and many other posts many times that’s how I went with the WD coz it shows it fully supports it just thought I’d expect it to for to 14xx mb/s like the 970 but unfortunately they don’t sell it here and I found the WD one that’s from the list in the other thread

 

[changareth]

Nope, with just one blade the throughput will double since the switch converts wide/slow PCIe v2.0 x8 or x16 to fast/narrow PCIe v3.0 x4.

Without a PCIe switched adapter, you will be always limited to the ~1450MB/s practical limit of a x4 PCIe v2.0 slot. All M.2 devices are x4.

Please read the first post of the PCIe thread and use the search in that thread to know more about things that you are in doubt, every question possible was answered that over the years.

RAID is not even supported with APFS for boot disks.

Hey bro! So my star tech pcie adaptor came and I installed my SN750 2TB on it but I’m still only getting a 1074 mb/s write and 1466 mb/s read which is actually 20mb slower than without it. Is there a reason for this? Was expecting for a surprise jump to 2000mb/s at least. As I read other post you linked someone used star tech pcie card too and with a single blade still managed to get the 2000mb+ speed. Is there something I’m doing wrong? I do see the link speed went to 8.0 Gt/S tho before was 5

 

[tsialex]

Hey bro! So my star tech pcie adaptor came and I installed my SN750 2TB on it but I’m still only getting a 1074 mb/s write and 1466 mb/s read which is actually 20mb slower than without it. Is there a reason for this? Was expecting for a surprise jump to 2000mb/s at least. As I read other post you linked someone used star tech pcie card too and with a single blade still managed to get the 2000mb+ speed. Is there something I’m doing wrong? I do see the link speed went to 8.0 Gt/S tho before was 5

Yes, you did install the card on slot 4, both slots 3 and 4 are 4x. The switched card needs to be installed on 1 or 2.

 

[changareth]

Yes, you did install the card on slot 4, both slots 3 and 4 are 4x. The switched card needs to be installed on 1 or 2.

Yeah I tried slot 2 . Slot 1 is display card atm. This is what I’m gettin.

 

[changareth]

Link width in system information still says x 4 tho

 

[Matty_TypeR]

I have tried these blades WD BLACK SN750 and found them not very good, erratic speeds when tested and returned them.

 

[tsialex]

Link width in system information still says x 4 tho

8GT/s x4 = PCIe 3.0 x4.

M.2 devices are always x4 (or less) PCIe devices, the link is correct for a PCIe switched card.

The read speed is also correct, the write speed is not, but this is probably a blade itself issue.

 

[changareth]

8GT/s x4 = PCIe 3.0 x4.

M.2 devices are always x4 (or less) PCIe devices, the link is correct for a PCIe switched card.

The read speed is also correct, the write speed is not, but this is probably a blade itself issue.

Damn suppose this SN750 should be 3,470/3,000MB/s read/write

 

[Matty_TypeR]

if you can get 2750 read and write you will be doing well.

 

[tsialex]

Damn suppose this SN750 should be 3,470/3,000MB/s read/write

Seems you still don't grasp the MacPro5,1 PCIe v2.0 limitations.

A high-end PCIe v3.0 M.2 device, like 970 Pro, will have the real life throughputs below:

• When installed to a dumb adapter to any PCIe 2.0 slot, x4 or x16 don't matter since a M.2 is always x4 (or less): ~1450MB/s
• When installed to a PCIe switched card with a x8 PCIe switch installed on a x4 slot: ~1450MB/s
• When installed to a PCIe switched card with a x8 PCIe switch installed on a x16 slot: ~2900MB/s
• When installed to a PCIe switched card with a x16 PCIe switch installed on a x4 slot: ~1450MB/s
• When installed to a PCIe switched card with a x16 PCIe switch installed on a x16 slot: ~3200MB/s

You can't get better results than ~3200MB/s with a MacPro5,1, for a single M.2 blade.

Btw, lot's of people had bad write throughput results with SN750 when installed in a MacPro5,1, it's an issue known for years.

 

[changareth]

Yeah i do understand that hence why I got the adaptor but I guess the SN750 is just the problem then. I would hope to at least get half the speed it says. Damn it. Guess gotta get a Samsung to hit 2k range for write.

Seems you still don't grasp the MacPro5,1 PCIe v2.0 limitations.

A high-end PCIe v3.0 M.2 device, like 970 Pro, will have the real life throughputs below:

• When installed to a dumb adapter to any PCIe 2.0 slot, x4 or x16 don't matter since a M.2 is always x4 (or less): ~1450MB/s
• When installed to a PCIe switched card with a x8 PCIe switch installed on a x4 slot: ~1450MB/s
• When installed to a PCIe switched card with a x8 PCIe switch installed on a x16 slot: ~2900MB/s
• When installed to a PCIe switched card with a x16 PCIe switch installed on a x4 slot: ~1450MB/s
• When installed to a PCIe switched card with a x16 PCIe switch installed on a x16 slot: ~3200MB/s

You can't get better results than ~3200MB/s with a MacPro5,1, for a single M.2 blade.

Btw, lot's of people had bad write throughput results with SN750 when installed in a MacPro5,1, it's an issue known for years.