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haaalp

macrumors newbie
Original poster
Jul 9, 2019
20
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Do you guys know if incorporating 2 x 500GB NVMe drives in RAID 0 is possible in slots 3 and 4 on the 5,1?

That would, in theory, get you in the ballpark of 3 GB/s (1.5 GB/s each), and effectively be the poor man's Sonnet RAID adapter w/ bifurcation. I understand that those same 500 GB drives could get you as fast as 4.8 GB/s r/w speeds in the Sonnet (taking advantage of all lanes, and maxing out the drive speed), but 2 NVMe adapters are $20 (and maybe not that great), but running the NVMe drive at only 1.5 GB/s each shouldn't run them too hot, no?

With that setup, you could be looking at $40 instead of $400. And 3 GB/s is no slouch either.

Is this possible?
 
Actually, you'll only be able to get about 1500MB/s whether single SSD or RAID. Slots 3 & 4 share a 4-lane PCIe connection, so your maximum throughput for the both of them is 4 x 500MB/s = 2GB/s, which results in about 1500MB/s or so after overhead. So, if you really want to get 3GB/s, you'll need to incorporate Slot 1 or 2, which are each on a dedicated x16 link.
 
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Sure? With ROM 144.0.0.0 you get the full speed in slot 2, that you dont get before (this was the problen for a limit on RAIDs, slot 2 750MB/s slot 3 1500 MB/s bring you down to 2x 750 MB/s). Two MVMe SSDs in slot 2 and 3 as RAID must give you around 3000 MB/s with the newest ROM.

lol sorry, dont read your last sentence 🧐
 
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Actually, you'll only be able to get about 1500MB/s whether single SSD or RAID. Slots 3 & 4 share a 4-lane PCIe connection, so your maximum throughput for the both of them is 4 x 500MB/s = 2GB/s, which results in about 1500MB/s or so after overhead. So, if you really want to get 3GB/s, you'll need to incorporate Slot 1 or 2, which are each on a dedicated x16 link.

Is that so? It is shared? That bums me out haha.

I couldn't find any info on that, do you know where I can read up on it? The apple site says:

PCI Express expansion
  • Three open full-length PCI Express expansion slots6
    • One PCI Express 2.0 x16 slot
    • Two PCI Express 2.0 x4 slots
  • All slots provide mechanical support for 16-lane cards
  • 300W combined maximum for all PCI Express slots
and doesn't seem to go into detail.

So could I add two NVMe adapters to slots 1 and 2 taking advantage of the 16 lanes and actually get closer to 2400 MB/s each, and 4800 MB/s RAID 0 Or would that require bifurcation?

Or could I just expect 1500 MB/s each, and be happy with 3000 MB/s in RAID? And place the GPU in slot three and hope it fits? If I leave slot 4 open, since the GPU will probably use up the bandwidth, do you think I'm not bottlenecking the GP too much? I plan to get a AMD Vega Frontier Edition.

To me, it would seem that faster read / writes are much more important than a GPU because I'm mostly processing photos, and right now, it seems the pics load pretty slow.

So many questions haha! But I want to do it right (or as close to right as possible) the first time.
 
Is that so? It is shared? That bums me out haha.

I couldn't find any info on that, do you know where I can read up on it? The apple site says:

PCI Express expansion
  • Three open full-length PCI Express expansion slots6
    • One PCI Express 2.0 x16 slot
    • Two PCI Express 2.0 x4 slots
  • All slots provide mechanical support for 16-lane cards
  • 300W combined maximum for all PCI Express slots
and doesn't seem to go into detail.

So could I add two NVMe adapters to slots 1 and 2 taking advantage of the 16 lanes and actually get closer to 2400 MB/s each, and 4800 MB/s RAID 0 Or would that require bifurcation?

Or could I just expect 1500 MB/s each, and be happy with 3000 MB/s in RAID? And place the GPU in slot three and hope it fits? If I leave slot 4 open, since the GPU will probably use up the bandwidth, do you think I'm not bottlenecking the GP too much? I plan to get a AMD Vega Frontier Edition.

To me, it would seem that faster read / writes are much more important than a GPU because I'm mostly processing photos, and right now, it seems the pics load pretty slow.

So many questions haha! But I want to do it right (or as close to right as possible) the first time.
To have more than one M.2 blade with the same slot, you need a PCIe switched adapter. While PCIe slots 1 and 2 are x16, M.2 devices are x4 and are limited to ~1500MB/s with a PCIe v2.0 x4 even if you install on slot 1 or 2. Only a PCIe switch can convert slow and wide PCIe v2.0 x16 into fast and narrow PCIe v3.0 x4.

Bifurcation don't apply to Macs, all Mac Pros besides 2019 Mac Pro are too old to have a chipset that support it and even 2019 Mac Pro, the only Mac that have a chipset that have support, don't have the firmware part of the Intel Lane Partition, the real name of bifurcation.

Slots 3 and 4 share the same 4 PCIe lanes to the CPU via a PCIe switch, the big BGA chip near the Intel south bridge on the backplane, between SATA connectors 2 and 3.



MP51 - SPI - Logic Board 2.jpg

[automerge]1590836859[/automerge]
Read the first post of the thread:

 
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Thanks for the detailed explanations, @tsialex. I've scanned over that page about 6 or 7 times now, but each time I can get a little better understanding. For example, just learned the OWC adapter is 8 lanes and seems quite steep in price.

It would seem now that the only way to do a "poor man's M.2 solution" would be 2 x cheap adapters in slots 2 x 3 in RAID 0 gaining about 3 GB/s. Seems about equivalent to the OWC but without a fan and takes up two slots.

Can't decide if I should even try that, wondering if I should just go big or go home.
 
Thanks for the detailed explanations, @tsialex. I've scanned over that page about 6 or 7 times now, but each time I can get a little better understanding. For example, just learned the OWC adapter is 8 lanes and seems quite steep in price.

It would seem now that the only way to do a "poor man's M.2 solution" would be 2 x cheap adapters in slots 2 x 3 in RAID 0 gaining about 3 GB/s. Seems about equivalent to the OWC but without a fan and takes up two slots.

Can't decide if I should even try that, wondering if I should just go big or go home.
You could buy the blades and the cheap adapters and test if works for you, then start to search a good promo on a SSD7101A-1.
 
Can't decide if I should even try that, wondering if I should just go big or go home.
What is your ultimate goal here? I don’t want to deter you from your fun, but are you after really good speed and utility, or is attaining the absolute maximum throughput to this storage the goal in itself? And do you already have the 500GB drives? Sounds like maybe not. If that’s the case, why not just keep it simple and grab a 1TB (or 2TB) and put it on an adapter card in slots 2-4? 1500MB/s is fantastically fast, and you’ll only know your proposed RAID0 at 3000MB/s is faster if you benchmark large file copies from a RAM disk or something. Again, I don’t want to deter you from your fun— because just the “thrill of the chase” can be a perfectly acceptable goal in itself— but if you’re just after a TB or 2 of really fast storage, a single blade can give you that with ease.
 
You could buy the blades and the cheap adapters and test if works for you, then start to search a good promo on a SSD7101A-1.

I wonder if there will be a promo in the near future. It seems right now, supply is being overwhelmed by demand for a variety of reasons. I could be wrong though.
 
What is your ultimate goal here? I don’t want to deter you from your fun, but are you after really good speed and utility, or is attaining the absolute maximum throughput to this storage the goal in itself? And do you already have the 500GB drives? Sounds like maybe not. If that’s the case, why not just keep it simple and grab a 1TB (or 2TB) and put it on an adapter card in slots 2-4? 1500MB/s is fantastically fast, and you’ll only know your proposed RAID0 at 3000MB/s is faster if you benchmark large file copies from a RAM disk or something. Again, I don’t want to deter you from your fun— because just the “thrill of the chase” can be a perfectly acceptable goal in itself— but if you’re just after a TB or 2 of really fast storage, a single blade can give you that with ease.

Thanks @fhturner, I really appreciate the response on a more conceptual level. I do not currently have the NVMe drives, but currently getting about 1 GB/s in my 2015 macbook pro, and that still seems sluggish when loading files in Lightroom 6. The GPU in that thing is the base model and think with 1.5 GB of VRAM. So perhaps there is some bottlenecks there, or perhaps it's just lightroom being laggy as usual. But it really doesn't feel any snappier than my current 2009 MP flashed to 5,1 running HS, 16 GB RAM, 8 core 2.66 and ATI 4870. One of these days I'll buy into the whole Adobe rental sphere, but trying to delay that as long as I can. On my '15 MBP, it can take around 4 seconds to load a preview, whereas the '09 MP takes about 6 seconds. I should probably do a clean install of Mojave on both systems though.

My plan was to upgrade the GPU, either to a used RX 580 or a new Vega 56. I wanted the VII (for 4k editing), but it's looking hard to find. Next was to get a PCIe solution to get at least 3 GB/s r/w, but then saw that it's quite possible to get close to 5 GB/s with a good adapter and two NVMe drives in RAID 0. I would not bother maxing it out with 4 drives, thinking the price / performance ratio wouldn't be as favourable. Last upgrade would be 2 x5675's or 5680's. Haven't really thought of upgrading the 1033 MHz RAM just yet.

Overall, the slow LR experience has certainly hindered my career and made me a lot less into processing my hundreds of thousands of photos that are just sitting on mechanical HD's (12 TB x 3 copies of each file).

So with all that being said, I'm happy to hear any advices, and pretty excited about upgrading but want to do it slowly and carefully so as to make the right decisions and not spend toooo much cash (the MP has been good to me for 11 years, so even spending $2k on somewhat future proof parts isn't too bad). My only real upgrades have been storage media. If you have any thoughts, I'm all ears. I'm not the kind of guy that is just trying to chase nice specs and then use it for web browsing and not much else. Would love to increase productivity at a decent value.
 
Thanks @fhturner, I really appreciate the response on a more conceptual level. I do not currently have the NVMe drives, but currently getting about 1 GB/s in my 2015 macbook pro, and that still seems sluggish when loading files in Lightroom 6. The GPU in that thing is the base model and think with 1.5 GB of VRAM. So perhaps there is some bottlenecks there, or perhaps it's just lightroom being laggy as usual. But it really doesn't feel any snappier than my current 2009 MP flashed to 5,1 running HS, 16 GB RAM, 8 core 2.66 and ATI 4870. One of these days I'll buy into the whole Adobe rental sphere, but trying to delay that as long as I can. On my '15 MBP, it can take around 4 seconds to load a preview, whereas the '09 MP takes about 6 seconds. I should probably do a clean install of Mojave on both systems though.

My plan was to upgrade the GPU, either to a used RX 580 or a new Vega 56. I wanted the VII (for 4k editing), but it's looking hard to find. Next was to get a PCIe solution to get at least 3 GB/s r/w, but then saw that it's quite possible to get close to 5 GB/s with a good adapter and two NVMe drives in RAID 0. I would not bother maxing it out with 4 drives, thinking the price / performance ratio wouldn't be as favourable. Last upgrade would be 2 x5675's or 5680's. Haven't really thought of upgrading the 1033 MHz RAM just yet.

Overall, the slow LR experience has certainly hindered my career and made me a lot less into processing my hundreds of thousands of photos that are just sitting on mechanical HD's (12 TB x 3 copies of each file).

So with all that being said, I'm happy to hear any advices, and pretty excited about upgrading but want to do it slowly and carefully so as to make the right decisions and not spend toooo much cash (the MP has been good to me for 11 years, so even spending $2k on somewhat future proof parts isn't too bad). My only real upgrades have been storage media. If you have any thoughts, I'm all ears. I'm not the kind of guy that is just trying to chase nice specs and then use it for web browsing and not much else. Would love to increase productivity at a decent value.

Hello! Just wanted to add my two cents to this post and offer any help where I can. I was in a similar boat as you - I used to heavily edit video on my cMP 4,1 with basically the same specs and then I updated to the last 15” MBP. In 2019... the difference was night and day.

Now during this time I’ve been trying to get my cMP running in a way so I can free up the use of my laptop and also have a backup machine. I’ve pretty much gotten it to a point where my cMP can export a 2 hour video roughly the same time as my 2019 MBP, which all things considering is pretty fantastic. But from what you’ve said with your specs, I think there’s a few things you can do to your MP which would greatly help your workflow:

CPU - Lightroom is very CPU intensive and the dual quad core just might not be cutting it. I‘d get the best CPU you can afford. I picked up delidded X5675s on eBay for about $90. The whole process took about 10 minutes.

GPU - the 4870s are SLOW for doing any sort of rendering. And in newer versions of macOS you may not even get hardware acceleration. I upgraded to the RX 580 and it’s been so night and day for me. Roughly $180

Memory - Adobe apps are memory hogs - I went from 8 2GB DIMMs to 6 16GB DIMMs at a faster clockspeed. I picked up 96GB of server RAM on eBay for around $150.

Overall, I think these changes may help your workflow significantly. But if you want to tackle one at a time, use LR on your MacBook Pro and launch Activity Monitor. Check the CPU usage during tasks, and memory usage overall. Find out the bottleneck there and see where you can improve it on the cMP.
 
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Overall, I think these changes may help your workflow significantly. But if you want to tackle one at a time, use LR on your MacBook Pro and launch Activity Monitor. Check the CPU usage during tasks, and memory usage overall. Find out the bottleneck there and see where you can improve it on the cMP.

Thanks! Glad to read about your experiences. Yes, I definitely plan to do all of that. Just want to do it right. Was also planning on grabbing some x5675's. In your opinion, what would you chance first? Did you add an NVMe drive as a scratch disk?
 
Overall, I think these changes may help your workflow significantly. But if you want to tackle one at a time, use LR on your MacBook Pro and launch Activity Monitor. Check the CPU usage during tasks, and memory usage overall. Find out the bottleneck there and see where you can improve it on the cMP.

Thanks! Glad to read about your experiences. Yes, I definitely plan to do all of that. Just want to do it right. Was also planning on grabbing some x5675's. In your opinion, what would you chance first? Did you add an NVMe drive as a scratch disk?
 
Thanks! Glad to read about your experiences. Yes, I definitely plan to do all of that. Just want to do it right. Was also planning on grabbing some x5675's. In your opinion, what would you chance first? Did you add an NVMe drive as a scratch disk?

I haven‘t added a NVMe drive to my computer yet, although I am greatly considering it. For now I’m okay with my external SSD drives and the performance I get out of them.

It’s honestly all up to you. If your CPU isn’t at full load during your work, then the extra cores might not help as much as something like RAM would.

The RX 580 is a great as addition as well, but I’m unsure of how GPUs work in Lr
 
I haven‘t added a NVMe drive to my computer yet, although I am greatly considering it. For now I’m okay with my external SSD drives and the performance I get out of them.

It’s honestly all up to you. If your CPU isn’t at full load during your work, then the extra cores might not help as much as something like RAM would.

The RX 580 is a great as addition as well, but I’m unsure of how GPUs work in Lr

Yeah, right now I'm trying to decide between the Vega 56 and Radeon Frontier Edition. The FE is looking like the best deal out there based on performance, but I've gotta bite the bullet and solder on some splices "pixlas mod" but actually soldered. That should be fun /s

That and I believe I'll just go for the NVMe adapter with the right switch, adn RAID 0 x 2 NVMe's which should be quite decent. Throw some delidded X5675's in there and call it a day. Still haven't decided if upgrading the RAM is worth it. Lightroom doesn't really use up my RAM, but I haven't tested any video editing software on this system yet.

Just trying to compile information so I can have all the parts ready when needed.
 
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