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SATA Express meets the '09 Mac Pro - Bootable NGFF PCIE SSD

flowrider said:
Yes - Slot 3 or 4. Installing in slot 2 will limit it's performance.

Lou
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TzunamiOSX said:
Slot 3 and 4 too, but not so much.

A Samsung SM951 has a read performance of up to 2000 MB/s in a PCIe 3.0 Slot
In slot 4 and 3 (4x) you get ~1450 MB/s
In slot 1 and 2 (16x) you get ~720 MB/s
Click to expand...


Forgive me if this has already been explained, but why does it get better performance in slot 3 and 4?

I though slot 1 and 2 are supposed to be the faster ones?

*This model has four full-length PCI Express (PCIe) 2.0 expansion slots, two x16 slots and two x4 slots. In the default configuration, one PCIe 2.0 x16 slot is occupied by the graphics card. Apple also reports that "all slots provide mechanical support for 16-lane cards" and there is a "300W combined maximum for all PCI Express slots."
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http://www.everymac.com/systems/app...-quad-core-2.66-early-2009-nehalem-specs.html
 
^^^^Slots 1 & 2 are no faster than slots 3 & 4, they just have more data lanes (16 vs 4). The Samsung SM951 and the Lycom card are 4 Lane devices. For some reason when the Samsung SM951 was inserted into Slot 2 by other members of this forum, they noticed degraded performance. Knowing this, I didn't even try Slot 2. Again, I don't know why, it's probably something to do with the failure of a 4 Lane device to properly negotiate the 16 Lanes. This does not apply to all devices however, I have a 2 Lane Apricorn Duo x2 in Slot 2 and it operates at the same speed as any other Slot.

Lou
 
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I see. Thanks, guys.

I have a Samsung 850EVO in an OWC Accelsior S PCIe card (I think it is actually a SATAIII(6Gbps) converter). Am I correct to assume it won't make a difference for that combo, or would I too benefit from sticking it in slot 3/4?
 
^^^^ In addition to my SM951 I have an Apricorn Duo x2 (with 2 Samsung SSDs) that works just fine in Slot 2 of my Mac Pro. Since the Accessor S is also a 2 Lane device, I don't see why it would behave differently. YMMV however.

Lou
 
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flowrider said:
^^^^ In addition to my SM971 I have an Apricorn Duo x2 (with 2 Samsung SSDs) that works just fine in Slot 2 of my Mac Pro. Since the Accessor S is also a 2 Lane device, I don't see why it would behave differently. YMMV however.

Lou
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Some people thinking it has something to do with the PLX bridge. You get only the full speed when the SM951 is connected to one of the PLX PCIe Slots.

Perhaps a SM951 controller issue, because the XP941 dont have this problem.

It would be nice to see a SM951 connected over an active PCIe Bridge in Slot 2. Perhaps this will help to get a 5.0 connection. Would be nice to have a 3000 MB/s RAID (1 in slot 2, 1 in slot 3)
 
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Found a good deal on a 512GB SM951 on eBay, bought a DT-120 adapter card (sourcing this part was somewhat harder than the SSD) and now I'm looking in amazement at my 6y-old MP flying at 1400+ MB/s :)

Next upgrades are going to be the GPU and a 4K/5K screen. This machine will never die! ;-)
 
I'm thinking of getting the Lycom adapter and SM951 as well (2010 Quad 2.8 5,1 Mac Pro), but I'm still on Mavericks, will it play nice, and is there any Mavericks-related advice you fine people would impart?

I'm thinking about TRIM in particular I guess - would I need to use a TRIM enabler tool? Or could I boot into an El Capitan partition, use the official command in El Capitan to enable TRIM, then boot back into Mavericks (would it 'stick'?)?

Thanks for any advice on this or anything else. I have read a lot of this thread but apologies if my questions should seem obvious, just want to check before investing so much on this :)
 
fiatlux said:
Found a good deal on a 512GB SM951 on eBay, bought a DT-120 adapter card (sourcing this part was somewhat harder than the SSD) and now I'm looking in amazement at my 6y-old MP flying at 1400+ MB/s :)
Click to expand...

As long as you realise that 1400MB/s only occurs when you are throwing large multi gigabyte files around.
 
The PCIe SSD (Lycom M.2 PCIe SSD to PCIe 3.0 x4 adapter / Samsung SM951 256GB) I set up is running fine and clocking good speeds but I don't see that much difference in working with FCP7 which I'm stuck with for the moment as well as other apps.

My main question is about TRIM. In my Apple system information it clearly says TRIM is not supported. Should it be? Is there any risk of losing data if it isn't? I'm on OS 10.8.5 and do a daily back up. Thanks.
 
^^^^The whole TRIM thing has been discussed many times on this forum. You can activate it by using a Terminal command. The command is "sudo trimforce enable" There is very little risk of losing data if it's not enabled, TRIM is mainly for housekeeping, but is, IMHO, a valuable tool for maintaining the health of your SSD. I have used TRIM since I started using SSDs. Do a search for TRIM both here and in Google and you'll get a better idea of it's benefits.

Lou
 
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^^^^Maybe I need it, since I can't seem to spell my name correctly:cool: But, you know, I've lived for a loooong time - and in all that time there are two things I have never tasted - One is coffee, the other beer. In my youth I spent four years in the USAF, and never had either one. I absolutely hate the smell of coffee:eek:

Lou
 
flowrider said:
^^^^Maybe I need it, since I can't seem to spell my name correctly:cool: But, you know, I've lived for a loooong time - and in all that time there are two things I have never tasted - One is coffee, the other beer. In my youth I spent four years in the USAF, and never had either one. I absolutely hate the smell of coffee:eek:

Lou
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Make that tea ...
 
flowrider said:
^^^^The whole TRIM thing has been discussed many times on this forum. You can activate it by using a Terminal command. The command is "sudo trimforce enable" There is very little risk of losing data if it's not enabled, TRIM is mainly for housekeeping, but is, IMHO, a valuable tool for maintaining the health of your SSD. I have used TRIM since I started using SSDs. Do a search for TRIM both here and in Google and you'll get a better idea of it's benefits.

Lou
Click to expand...

If you'll notice, had said he's running 10.8.5. Trimforce only became available in 10.10.4 onwards.

You can upgrade to 10.10.4+ or 10.11.x and just use 'trimforce enable', or Google the appropriate commands. I used the instructions written by Grant Pannell, but his site seems to have changed :/
 
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