What happens ... M.2 PCI-e SSD to PCI-e Adapter Card in Slot 1 ???

[petrev]

Hi,

So due to case constraints it seems I may have to put an M.2 PCI-e SSD to PCI-e Adapter Card into the first PCI-e 3 x16 slot usually used for the graphics card.

What will happen if the graphics card is in the second slot ? Will it be slowed or otherwise affected by the SSD card (x4) ?
True x16 slot or second slot already limited to x8 ?

Gigabyte always says
* For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16_1 slot.
Is this correct ? Why ?

If it is an x8 slot at position 2 I have read that it will be OK for all but the latest greatest (now) graphics cards - Is that correct ?

Thanks for any info,
P

[kalniel]

Depends on your motherboard. Usually it's in the manual how different combinations affect the wiring.

[petrev]

Depends on your motherboard. Usually it's in the manual how different combinations affect the wiring.

Have to try and find a download as this is a pre-purchase decision question.

Thanks.

[Bonebreaker777]

Agree, depends on the motherboard model. I think some SLI/Crossfire enabled models can assign free PCIe lanes to other slots if not all 16x are fully utilized in the first slot. But it depends on the motherboard and by a certain degree on the CPU. What platform you would be after?

Also I found this ( https://www.pugetsystems.com/labs/ar...rformance-518/ ). Tiny, negligible performance differences. I personally wouldn't be concerned.

[scaryjim]

... due to case constraints ...

Genuinely intrigued; what case & mobo combination are you looking at that might force this position on you? From a quick google I can't see anything that would suggest an adapter would struggle for placement because of a case layout?

[kalniel]

Genuinely intrigued; what case & mobo combination are you looking at that might force this position on you? From a quick google I can't see anything that would suggest an adapter would struggle for placement because of a case layout?

If it's anything like my recent predicament then it's probably the GPU that's the obstruction needing it to go to the other slot.

[scaryjim]

If it's anything like my recent predicament then it's probably the GPU that's the obstruction needing it to go to the other slot.

That just sounds like an excuse to get the power tools out to me

[petrev]

Agree, depends on the motherboard model. I think some SLI/Crossfire enabled models can assign free PCIe lanes to other slots if not all 16x are fully utilized in the first slot. But it depends on the motherboard and by a certain degree on the CPU. What platform you would be after?

Also I found this ( https://www.pugetsystems.com/labs/ar...rformance-518/ ). Tiny, negligible performance differences. I personally wouldn't be concerned.

Hi,

Thanks for the link.

I was looking at Z170 i5 6600 based systems ...
But
I am now more restricted as thinking Z97 i5 5675 as I want to keep using Win 8.1 for as long as I want ......?

[petrev]

Genuinely intrigued; what case & mobo combination are you looking at that might force this position on you? From a quick google I can't see anything that would suggest an adapter would struggle for placement because of a case layout?

Hi,

Case is a Fanless HD-PLEX H5 II

I am probably not going to fit a Graphics card now as having gone back to the drawing board with the i5 5675 and revisited the Case I find that a Graphics card can only be in slot 1 or 2 positions and no boards have an x4 slot at 1 and an x16 slot at 2 so as the card I may want to fit is x4 (PCIe x4 M2 SSD) then there are no slots for anything available to graphics card.

The only MB I can find with a DP socket and Slot one an x16 is the Asus Z97 Gryphon Armour micro ATX.

The case further precludes any card of more than half height without a riser cable and I am not sure how the modern fast devices fare with cables introduced into the mix ???

@kalniel - Like the wonderful story of the new Graphics Card - Had many similar easy jobs take far too much effort over the years

P

[scaryjim]

What's wrong with getting a mobo with a native M.2 port?

[petrev]

What's wrong with getting a mobo with a native M.2 port?

Hi,

Z97 boards are at x2 lanes for M2 slot so would throttle a fullish speed card like Samsung 951 or 950 Pro (apparently)

I may be wrong.

Maybe I don't need an M2 ? How much slower is an 850 ??

P

[scaryjim]

The difference between most SSDs in consumer real-world usage is negligible. The differences are measurable, sure, and some of them look quite significant, but the key is that an SSD of any type is at least 100x faster than a normal HDD for the test that matters (random access iops). The fact that SSD x is 2x, or even 10x, faster than SSD y is kind of irrelevant in the face of that huge performance increase over spinning rust.

As it is, PCIe 2.0 x2 offers (theoretically) around twice the bandwidth of SATA 3. Anandtech have a nice test of an ASRock board that implements both M.2 2x and M.2 4x slots: http://www.anandtech.com/show/8045/a...-with-xp941/11 - from their testing an M.2 PCIe SSD in an x2 slot should be faster than a SATA 3 SSD (they get read/write of around 700MBps/800MBps), but a little slower than in an x4 slot (1GBps each way). SATA 3 should give you a bit over 500MBps each way, depending on drive. My opinion, as per the first paragraph, is that while those differences can be measured they're unlikely to be noticeable in typical consumer/enthusiast usage patterns: only very specific workloads tend to be IO constrained, and most people know if they're running one of those. So whilst there is a difference in performance between SATA 3, PCIe x2 and PCIe x4, it's utterly negligible compared to the performance benefits of running an SSD in the first place

tl;dr? You won't notice the difference. Which is all that really matters

[petrev]

Thanks scaryjim

So from that great info I guess a Samsung 850 EVO would save about £130 over a 950 M2 and running at x2 without the extra £25 adapter card for x4.

Yay - Pretty similar massive extra performance minus 155 quid - top marks ! Where is the thanks button on this forum ?

Thanks jim

p.s. What is "tl;dr?"

[kalniel]

p.s. What is "tl;dr?"

Too long; didn't read.

[petrev]

Ah ha !

Thanks - Found the Thanks button but only on my phone browser ??? Win Phone 8.1 !

So would people agree that an Asus with M2 2x and USB 3.1 would be a better bet than ASRock with M2 x4 (no 3.1)
especially as it seems I should go SATA SSD and save a bunch of dosh !

Is this now the wrong thread for this ?

P.

[kalniel]

The thanks button might only appear when you've got a certain number of contributing posts - I think around 15 which would explain why you're suddenly seeing it - refresh cache if you don't see it

This thread's still fine- it's a related/subsequent question, but no worries if you'd prefer to ask a new question in a different thread, especially if unrelated.