MP All Models PCIe SSDs - NVMe & AHCI

[Canubis]

I see the Crucial P3 listed as Good in the first post.
Is the Crucial P3 Plus the same or is this a completely different ssd?

Anyone having experience with the Crucial P3 Plus, specifically the 4TB blades together with an OWC Accelsior 4M2 in a Mac Pro 7,1?

Many thanks in advance! Appreciate your insights!

 

[Trajko]

Just to confirm that Kioxia xg6 works like charm, straight away after connecting nothing extra needed fully compatible, r/w 1480/1456 on the simple adapter and heath sink, keeping low temperature, tried it with a couple of hours with handbrake. Will probably try gx8 gen 4, with doubled speeds. Probably nothing to do with the drive, but it is recognised as internal disc while I was expecting being external one! Mac Pro 5,1.

 

[basslik]

I got a quick question. I have

Syba I/O Crest SI-PEX40129 Dual M.2 NVMe​

In my 5,1 placed in the 16x8 slot.

I want to move to the next slot, which of course it's slower, 4x8.

But since the Crest is only a dual, it shouldn't matter, and achieve the same speeds?

Thanks.

 

[tsialex]

I got a quick question. I have

Syba I/O Crest SI-PEX40129 Dual M.2 NVMe​

In my 5,1 placed in the 16x8 slot.

There is no 16x8 PCIe slot.

The two x16 slots (slots 1 and 2) are PCIe v2.0 x16, with the x16 meaning that are 16 PCIe lanes available for a card to use.

I want to move to the next slot, which of course it's slower, 4x8.

Also 4x8 means absolutely nothing.

The MacPro4,1 and MacPro5,1 x4 slots (slots 3 and 4) are physically and electrically x16, but with just 4 PCI lanes available, shared from the X58 southbridge via a PCIe switch.

But since the Crest is only a dual, it shouldn't matter, and achieve the same speeds?

Thanks.

Wrong - moving to one of the two x4 slots will limit the TOTAL throughput of the card to around ~1450 MB/s and increase the latency, since now you connected to the IDT PCIe switch that connects to the southbridge, then it connects to the CPU.

So, it will work at half speed since the SI-PEX40129 is a x8 PCIe card and capable of 2800 to 2900 MB/s with a fast NVMe blade or RAID array when installed to one of the Mac Pro x16 slots.

 

[basslik]

There is no 16x8 PCIe slot.

The two x16 slots are PCIe v2.0 x16, with the x16 meaning that are 16 PCie lanes available.



Also 4x8 means absolutely nothing.

The MacPro4,1 and MacPro5,1 x4 slots (slots 1 and 2) are physically and electrically x16, but with just 4 PCI lanes shared from the southbridge via a PCIe switch.



Wrong - moving to one of the two x4 slots (slots 3 and 4) will limit the TOTAL throughput of the card to around ~1450 MB/s and increase the latency, since now you connected to the IDT PCIe switch that connects to the southbridge then it connects to the CPU.

So, it will work at half speed since the SI-PEX40129 is a x8 PCIe card and capable of 2800 to 2900 MB/s with a fast NVMe blade or RAID array when installed to one of the Mac Pro x16 slots.

Thanks Alex.

Greatly appreciate the info. Crest will remain in slot 2👍