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rw3

macrumors 6502a
Original poster
May 13, 2008
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DFW, TX
Just wanted to clarify for everyone where the "other" PCIe flash blade will go in the Mac Pro. See annotated picture.
 

Peace

Cancelled
Apr 1, 2005
19,546
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Space The Only Frontier
You're looking at the slide that shows graphics. Scroll to the next slide and it clearly shows the storage in the same spot.

There are not two slots for storage.
 

Stetrain

macrumors 68040
Feb 6, 2009
3,550
20
Seems kind of strange that they would even bother with having a version of the GPU card without the SSD connector on it.

You would think it would be cheaper just to have a single version of the GPU card and leave the slot available for expansion.
 

Quu

macrumors 68040
Apr 2, 2007
3,419
6,789
Seems kind of strange that they would even bother with having a version of the GPU card without the SSD connector on it.

You would think it would be cheaper just to have a single version of the GPU card and leave the slot available for expansion.

Cheaper to mass produce one PCB and just not include the parts on it to support the SSD stick. This is very common, see GTX 780 vs GTX Titan. Same graphics card PCB, but the GTX 780 has blank areas on the PCB where more RAM chips would go that have been omitted.
 

VirtualRain

macrumors 603
Aug 1, 2008
6,304
118
Vancouver, BC
Yes. I do.

On the left is a flat spot with no connector. On the right is a PCIe slot with a connector.

This could be a pre-production model that only has only one PCB fully populated, or it could be there for future use with no intention of adding it for the upcoming model. We just won't know until the production model is available.
 

rw3

macrumors 6502a
Original poster
May 13, 2008
679
41
DFW, TX
Yes. I do.

On the left is a flat spot with no connector. On the right is a PCIe slot with a connector.

In order to achieve anything over 1GB/s reads, you will need a second PCIe based flash module. The Mac Pro will use the same module (specs wise) as the new MacBook Air is using, which tops out at ~800MB/s reads....point proven.
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,164
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Finland
In order to achieve anything over 1GB/s reads, you will need a second PCIe based flash module. The Mac Pro will use the same module (specs wise) as the new MacBook Air is using, which tops out at ~800MB/s reads....point proven.

The Mac Pro demo unit had different NAND than the MBA, they aren't the same. You'll be getting over 1GB/s with a single SSD in Mac Pro.
 

VirtualRain

macrumors 603
Aug 1, 2008
6,304
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Vancouver, BC
In order to achieve anything over 1GB/s reads, you will need a second PCIe based flash module. The Mac Pro will use the same module (specs wise) as the new MacBook Air is using, which tops out at ~800MB/s reads....point proven.

That was my thinking initially as well, but then Hellhammer (who seems to have beat me to it above) pointed out this...

The most likely reason is that the speeds Apple is claiming are for 512GB or 1TB SSD. With PCIe we're no longer capped at 550MB/s so more NAND yields better performance also at the highest capacities.

https://forums.macrumors.com/posts/17418769/
 

rw3

macrumors 6502a
Original poster
May 13, 2008
679
41
DFW, TX
You're making an assumption. We don't know for sure. But as it stands right now there is only one slot.Officially.

Just as much are you are making an assumption that there will only be one connector.

Hellhammer - I don't care if it's different NAND, it won't make up for 400MB/s difference.
 

Cubemmal

macrumors 6502a
Jun 13, 2013
824
1
The cards aren't identical, you can see that the arrangements of caps on the top is different. While obviously there is a benefit to identical cards there's no mandate. The parts are small and they're doing custom PC boards regardless so if there is any reason for them to be different I'm not surprised that they are. Clearly the boards have a lot in common though.

We don't know any other constraints too, maybe the layout precludes an extra PCI lane on this board as the other. The evidence for the possibility of another board is incidental.

Finally, I don't get why anybody cares, you're barking up the wrong tree. Apple has firmly said that the days of internal upgrades (other than minor RAM and maybe flash) are over as far as they are concerned.
 

theluggage

macrumors 604
Jul 29, 2011
7,475
7,313
In order to achieve anything over 1GB/s reads, you will need a second PCIe based flash module. The Mac Pro will use the same module (specs wise) as the new MacBook Air is using, which tops out at ~800MB/s reads....point proven.

Some sites are claiming that the Air is using the Samsung XP941 which claims a sequential read performance of 1,400MB/s.

That's also interesting, because it would mean the SSD isn't a proprietary Apple part, which would be good news for third-party upgrades. However, you have to string together 2-3 websites to reach that conclusion so don't bet on it.

However, as for the second slot in the Pro, all we can tell from the photos is that - at least for the prototypes - Apple are using the same basic PCBs layouts for both of the GPU cards (sensible economy). That doesn't mean that if they soldered a socket in there it would work. So its a possibility, but not a cert.
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,164
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Finland
Hellhammer - I don't care if it's different NAND, it won't make up for 400MB/s difference.

It will do over 1GB/s without a doubt. The 512GB SSD in MBA does ~725MB/s read and write, but it's very uncommon for an SSD to have equal read and write performance (reading from NAND is much faster than writing to it). That means there's likely some throttling going on (probably through firmware) because the interface itself is good for up to 1GB/s. It would make sense for the reads to be in the ~1200MB/s range if the write performance is a little over 700MB/s.

Samsung has also officially announced the PCIe-based M.2 SSD and claims that it's good for up to 1.4GB/s.

Some sites are claiming that the Air is using the Samsung XP941 which claims a sequential read performance of 1,400MB/s.

That's also interesting, because it would mean the SSD isn't a proprietary Apple part, which would be good news for third-party upgrades. However, you have to string together 2-3 websites to reach that conclusion so don't bet on it.

The SSDs Apple use are proprietary but only in the sense that the connector is proprietary, other parts of the hardware like controller and NAND are not. This hasn't changed, the M.2 connector is different from the one Apple uses in new MBAs and in the demo Mac Pro.
 

Peace

Cancelled
Apr 1, 2005
19,546
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Space The Only Frontier
Just as much are you are making an assumption that there will only be one connector.

Hellhammer - I don't care if it's different NAND, it won't make up for 400MB/s difference.

I'm not making any assumption. Just going by what Apple showed. and Apple did NOT show two connectors.
 

VirtualRain

macrumors 603
Aug 1, 2008
6,304
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Vancouver, BC
It will do over 1GB/s without a doubt. The 512GB SSD in MBA does ~725MB/s read and write, but it's very uncommon for an SSD to have equal read and write performance (reading from NAND is much faster than writing to it). That means there's likely some throttling going on (probably through firmware) because the interface itself is good for up to 1GB/s. It would make sense for the reads to be in the ~1200MB/s range if the write performance is a little over 700MB/s.

Samsung has also officially announced the PCIe-based M.2 SSD and claims that it's good for up to 1.4GB/s.



The SSDs Apple use are proprietary but only in the sense that the connector is proprietary, other parts of the hardware like controller and NAND are not. This hasn't changed, the M.2 connector is different from the one Apple uses in new MBAs and in the demo Mac Pro.

Thanks for the insights... do you know how many PCIe lanes need to be budgeted for these SSDs? Is it a x2 PCIe 2.0 interface?
 

rw3

macrumors 6502a
Original poster
May 13, 2008
679
41
DFW, TX
After some further research, two SSDs aren't needing for that read speed, although it would be nice to be able to have a couple of SSDs in there.

Here's to hoping...
 

MattInOz

macrumors 68030
Jan 19, 2006
2,760
0
Sydney
The SSDs Apple use are proprietary but only in the sense that the connector is proprietary, other parts of the hardware like controller and NAND are not. This hasn't changed, the M.2 connector is different from the one Apple uses in new MBAs and in the demo Mac Pro.


Is the Apple connector propriety or is it just a bog standard PCIe connector?

Not the mini-PCIe connector of the wifi modules. From the close up shots on iFixit it looks like a standard PCIe up to the key notch but has more pins than x1 and not enough for x4. Almost like it's a x2 if such a thing existed.

Curious to see if you plugged it in to a spare slot in a Mac Pro would it just show up?
(yes possibly very expensive curiosity)
 

Wreckem

macrumors member
Apr 19, 2010
97
0
In order to achieve anything over 1GB/s reads, you will need a second PCIe based flash module. The Mac Pro will use the same module (specs wise) as the new MacBook Air is using, which tops out at ~800MB/s reads....point proven.

You do not need dual PCIe SSDs in RAID to hit over 1GB/s read

The technology is there to do much more with a single drive. ADATA has been showing off a single M.2 drive that does 1800MB/s. Apple only said up to 2.5x faster than SATA 3 SSDs which puts the drive in the 1300MB/s range. Bottom line is there are going to be some EXTREMELY fast drives coming out later this year/early next year.

Furthermore, if RAID was necessary, they can do RAID on a single stick, one drive on each side of the PCB.

But yeah, you can bet Apple will have options for dual ports for dual PCIe ssds.
 
Last edited:

Wreckem

macrumors member
Apr 19, 2010
97
0
Thanks for the insights... do you know how many PCIe lanes need to be budgeted for these SSDs? Is it a x2 PCIe 2.0 interface?

Not sure what Apple is using, but M.2 socket 3 uses PCIe 2.0 x4 lanes. The New Mac Pro will be on the bleeding edge for ssd speed, and there won't be much on the PC desktop side of things as there are only a handful of PC motherboards that offer M.2 slots(all are ROG boards from Asus). PC laptops will have faster storage options than most PC desktops until next year(Intels 9 series chipset). I know Apple isn't using M.2 but they are using something similar that is PCIe based and if I had to guess its x4 as well.

I for one hope the Asus ROG Maximus Impact is easy to umm you get the idea, since Apple still refuses to have something in between the imac and the mac pro.
 

VirtualRain

macrumors 603
Aug 1, 2008
6,304
118
Vancouver, BC
Furthermore, if RAID was necessary, they can do RAID on a single stick, one drive on each side of the PCB.

This is already done at a lower level... SSDs effectively stripe data across NAND chips in parallel to achieve faster speeds which is why larger capacity drives with more NAND chips perform better... They can fully utilize all the channels of the controller in parallel exactly the same as a RAID0 array of drives works.

----------

Not sure what Apple is using, but M.2 socket 3 uses PCIe 2.0 x4 lanes. The New Mac Pro will be on the bleeding edge for ssd speed, and there won't be much on the PC desktop side of things as there are only a handful of PC motherboards that offer M.2 slots(all are ROG boards from Asus). PC laptops will have faster storage options than most PC desktops until next year(Intels 9 series chipset). I know Apple isn't using M.2 but they are using something similar that is PCIe based and if I had to guess its x4 as well.

I for one hope the Asus ROG Maximus Impact is easy to umm you get the idea, since Apple still refuses to have something in between the imac and the mac pro.

Yeah, I guess it has to be either x4 PCIe 2.0 or x2 at 3.0 speeds to not be a bottleneck.
 

Wreckem

macrumors member
Apr 19, 2010
97
0
This is already done at a lower level... SSDs effectively stripe data across NAND chips in parallel to achieve faster speeds which is why larger capacity drives with more NAND chips perform better... They can fully utilize all the channels of the controller in parallel exactly the same as a RAID0 array of drives works.

Yes, but that doesn't mean you can't RAID0 two SSDs. And the M.2 standard allows for RAID 0 on a single stick(although probably pointless), or larger capacity drive, or a drive and a wifi/bluetooth module. Also larger capacity drives aren't necessarily faster. For read they are all about the same, for write 256GB is the sweet spot as they are faster than smaller models(128GB) and larger models(480GB+). But thats on SATA III, thats all going to change going forward later this year and next.
 

Hellhammer

Moderator emeritus
Dec 10, 2008
22,164
582
Finland
Thanks for the insights... do you know how many PCIe lanes need to be budgeted for these SSDs? Is it a x2 PCIe 2.0 interface?

Depends on whether we're dealing with PCIe 2.0 or 3.0. With 2.0 it has to be x4 for speeds greater than 1GB/s but with 3.0 you could get by with x2 (the one in MBA is PCIe 2.0 x2, so that does exist).

The interesting question is that how will Apple use the PCIe lanes with six Thunderbolt ports. Even TB2 is still PCIe 2.0 x4, so TB alone requires twelve PCIe lanes. You get 40 3.0 lanes from the CPU and Apple is probably using 32 (2x16) for the GPUs, so that leaves us with eight 3.0 lanes and eight 2.0 lanes (coming from the PCH).

If the SSD supports PCIe 3.0, then the best option would be to have two 3.0 x2 slots for the SSDs (assuming there's two) and then onw 3.0 x4 slot for one of the TB controller. The rest of the TB controllers would connect to the PCIe lanes coming from the PCH.

Is the Apple connector propriety or is it just a bog standard PCIe connector?

Not the mini-PCIe connector of the wifi modules. From the close up shots on iFixit it looks like a standard PCIe up to the key notch but has more pins than x1 and not enough for x4. Almost like it's a x2 if such a thing existed.

There's no official PCIe x2 spec, so it's custom (though it might be what PCIe x2 would look like).

Curious to see if you plugged it in to a spare slot in a Mac Pro would it just show up?
(yes possibly very expensive curiosity)

With the right adapter, it should show us as it's nothing more than a PCIe device.
 
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