Amfeltec PCI Express Splitter

[nbritton]

What are your thoughts on this?: http://amfeltec.com/products/flexible-x4-pci-express-to-4-minipci-express-splitter/

I was thinking maybe I could use it to convert the 3.5" drive bays to accommodate mini PCIe SSD. I'm wondering if performance would be worth it. PCIe 2.0 x4 is 2000 MB/s, and I recall the Mac Pro 5,1 has SATA-300.

 

[William_si]

I have this one:

http://amfeltec.com/products/flexible-x4-pci-express-4-way-splitter-gpu-oriented/

Which should be the same PLX chip.

It works fine in slot 3/4 on my 4,1/5,1 (see usage here, external GPUs), the ones expanding 1 lane to 3 lanes (eg. this one - i had a POC visible here which did not work in a Mac Pro but fine in another system) are very hit or miss, especially the PCIe 1.0/1.1 based ones.

If you want to inquiry pricing with Amfeltec.... not cheap. 250$+ for mine.


If you can get mini PCIe actual PCIe (so not mSATA which is the same slot and not compatible) SSDs with any reasonable speed (x1 2.0 effectively cuts at 450MB/s anyway, but this tech is old sooooo... either rare and not cheap or slow) or can convert them to m.2 (exists, but you connect an x4 SSD to x1 one then and pay that premium) your plan works and is faster than the SATA2 based bays.

Keep in mind you share the x4 in slot 3 with slot 4 by another PLX chip and that RAID volumes booted from cannot be Filevault encrypted.

 

[cmabolt]

I have this one:

http://amfeltec.com/products/flexible-x4-pci-express-4-way-splitter-gpu-oriented/

Which should be the same PLX chip.

It works fine in slot 3/4 on my 4,1/5,1 (see usage here, external GPUs), the ones expanding 1 lane to 3 lanes (eg. this one - i had a POC visible here which did not work in a Mac Pro but fine in another system) are very hit or miss, especially the PCIe 1.0/1.1 based ones.

If you want to inquiry pricing with Amfeltec.... not cheap. 250$+ for mine.


If you can get mini PCIe actual PCIe (so not mSATA which is the same slot and not compatible) SSDs with any reasonable speed (x1 2.0 effectively cuts at 450MB/s anyway, but this tech is old sooooo... either rare and not cheap or slow) or can convert them to m.2 (exists, but you connect an x4 SSD to x1 one then and pay that premium) your plan works and is faster than the SATA2 based bays.

Keep in mind you share the x4 in slot 3 with slot 4 by another PLX chip and that RAID volumes booted from cannot be Filevault encrypted.

Hi William, We are specking a systems for a 2012 5.1 mac using it's 2 x16 PCIe slots. We're hoping to use 4 GPU's on each slot with amfeltec's cluster solutions. I'm reading that the mac will only work with 4 gpu's period? Any thought on how to configure this.

Thanks Chris

 

[AidenShaw]

Hi William, We are specking a systems for a 2012 5.1 mac using it's 2 x16 PCIe slots. We're hoping to use 4 GPU's on each slot with amfeltec's cluster solutions. I'm reading that the mac will only work with 4 gpu's period? Any thought on how to configure this.

Thanks Chris

Investigate companies like OneStopSystems (https://www.onestopsystems.com/3u-compute-accelerator-nvidia-tesla-gpus) which specialize in making external PCIe expansion chassis - up to 16 GPU.

These come with PCIe x16 cards that have a connector to the chassis. For many applications, splitting an x16 slot to eight x16 GPUs is reasonable.

Amfeltec is kind of an amateur in this market.