SSD Speeds on 5.1

mastermamo

macrumors member
Original poster
Jan 14, 2017
78
30
Cape Town South Africa
Hi guys

I have a general question which perhaps a few of u can shed some light on.
I have a few Mac Pros but on my 2012 12 core I use 3 SSD's.
! x Samsung EVO 850 (Boot Drive)
1 x Samsung Evo 840 (CCC Backup Drive)
1 x OWC Mercury Electra 6G (Scratch Drive)

The max speeds on these are 6Gb/s. I know the Macs support SATA 2 and not 3 but is there a workaround to achieve max speeds?
Is there any possible way to reach the 6Gb/s speeds these drives are capable off or will I need to go the flash based Pci-e drive route?
[doublepost=1484586342][/doublepost]Oh dear ok I just saw this post which answers my question

https://forums.macrumors.com/threads/ssd-in-mp-5-1-not-expected-results.1974827/
 

AndreeOnline

macrumors 6502
Aug 15, 2014
443
259
Zürich
In a single bay you'll hit the ceiling, real life, at around 220 to 235 MB/s write and 260 MB/s read.

If you RAID 0 two over two bays you get closer to the drives capacity at double those numbers.

Remember that all those fancy read/write speeds you see is with larger files. Day to day, while there is a difference between Sata 3Gbps and PCIe, the difference might be smaller than you think in many situations with smaller read/writes. To me personally, SSDs are primarily about the fast access times.
 
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flowrider

macrumors 603
Nov 23, 2012
6,114
2,321
If you have the slots, I would, and did, go with PCIe cards.

I have an Angelbird with an SM951 and an Apricorn Velocity Duo with Samsung SSDs (1 840 Pro and 1 840 EVO). Speeds are attached. The first is the SM951, The second the Pro on the Card, the third an EVO in a drive bay.

Lou

AJA SM951.jpg AJA 840 Pro Duo x2.jpg AJA 840 Evo SATA Slot.jpg
 
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macuser453787

macrumors 6502a
May 19, 2012
576
151
Galatians 3:13-14
The max speeds on these are 6Gb/s. I know the Macs support SATA 2 and not 3 but is there a workaround to achieve max speeds?
There is a hardware-based solution that works very well. Check out this product from Max Upgrades. This kit includes drive sleds with a custom connector that uses the Mac Pro's backplane for POWER only, NOT for DATA.

It requires using a controller card with mini-SAS connectivity (such as a RAID controller), but using this kit you can achieve proper SATA 3 speeds with your single drives. Another benefit of this option is that if you choose to use RAID, using a RAID controller card takes the RAID calculations away from the CPU, which frees up the CPU to work on other tasks. (This is in contrast to using a software-based RAID setup, which relies on the CPU for its calculations.)

I have this setup in my cMP 4,1(5,1) hooked up to an Areca controller with 4 Samsung 840 Pros in a RAID stripe and AJA benchmarks it at about 1900 MB/s.

The flip side of this setup is of course the price of the kit and the controller card.
 

AlanKeaveney

macrumors newbie
Feb 22, 2017
6
0
Galway, Ireland
If you have the slots, I would, and did, go with PCIe cards.

I have an Angelbird with an SM951 and an Apricorn Velocity Duo with Samsung SSDs (1 840 Pro and 1 840 EVO). Speeds are attached. The first is the SM951, The second the Pro on the Card, the third an EVO in a drive bay.

Lou

View attachment 683989 View attachment 683990 View attachment 683991
Hi Flowrider,
Ive been trying to find out what would the bottleneck be in my 2009 4,1->5,1 MP for a m.2 SSD upgrade.
Have you that Angelbird in a PCI-E 2 x16 slot?

Below is the max speeds I saw on site on PCI-Express:


Summary of PCI Express Interface Parameters:
  • Base Clock Speed: PCIe 3.0 = 8.0GHz, PCIe 2.0 = 5.0GHz, PCIe 1.1 = 2.5GHz
  • Data Rate: PCIe 3.0 = 1000MB/s, PCIe 2.0 = 500MB/s, PCIe 1.1 = 250MB/s
  • Total Bandwidth: (x16 link): PCIe 3.0 = 32GB/s, PCIe 2.0 = 16GB/s, PCIe 1.1 = 8GB/s
  • Data Transfer Rate: PCIe 3.0 = 8.0GT/s, PCIe 2.0= 5.0GT/s, PCIe 1.1 = 2.5GT/s

 

flowrider

macrumors 603
Nov 23, 2012
6,114
2,321
^^^^My Angelbird is in PCIe slot 3, a 4X slot. The Apricorn is in slot 2. IIRC there are problems with the SM951 associated with being mounted in slot 2.

Lou
 
Last edited:

macuser453787

macrumors 6502a
May 19, 2012
576
151
Galatians 3:13-14
Ive been trying to find out what would the bottleneck be in my 2009 4,1->5,1 MP for a m.2 SSD upgrade.
Have you that Angelbird in a PCI-E 2 x16 slot?
I have the Angelbird as well (with an SM951 mounted on it), and I believe the x4 slot is the appropriate slot for that card because the card itself is x4 and putting it in an x16 slot won't yield higher speeds.
 

Motoman69

macrumors newbie
Apr 9, 2014
3
0
Tulsa, OK
Will the Angelbird work with the new Samsung 860 EVO NVME? . I just got one for a PC and have a cheap PCIE card. I also have a Apricorn Velocity Duo with std Samsung 850 EVO, Did you have to update the MacOS with any Kext files for the Angelbird SM951 combo?
 

PowerMike G5

macrumors 6502
Oct 22, 2005
459
176
New York, NY
^^^^My Angelbird is in PCIe slot 3, a 4X slot. The Apricorn is in slot 2. IIRC there are problems with the SM951 associated with being mounted in slot 2.

Lou
Yes, I had issues with the SM951 in the x16 slot 2 using the Lycom DT-120. The only solution that seems to work In the x16 slot 2 is the Amfeltec card. It divides the slot into four x4 slots on the card and runs each one at full speed. I have it with an SM951 in each slot and I achieve the 1400MB/s-1500MB/s average on each one.
 

Squuiid

macrumors 68000
Oct 31, 2006
1,593
899
Will the Angelbird work with the new Samsung 860 EVO NVME? . I just got one for a PC and have a cheap PCIE card. I also have a Apricorn Velocity Duo with std Samsung 850 EVO, Did you have to update the MacOS with any Kext files for the Angelbird SM951 combo?
NVME won't work in a Mac Pro. There are hacky drivers for it but not worth the trouble IMO, and it wouldn't be bootable.
No drivers are required for the SM951/Angelbird/Lycom combos.
However, the SM951 and XP941 drives are hard to find. Your best bet is the following:
HyperX Predator PCIe 480GB AHCI SSD (The only compatible PCIe SSD for the Mac Pro that's still readily available)
https://www.amazon.com/gp/product/B00V01C6M8/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
 
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