[SFF Network] John's Weekly Mini-Rant - M-STX, Do We Really Need Another Form Factor?

confusis

John Morrison. Founder and Head writer SFF.N
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Jun 19, 2015
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This is one of a series of weekly mini-rants by your faithful correspondent, John Morrison. These is a regular series focusing on issues in the SFF niche. All content is entirely opinion of John, not of SmallFormFactor.net, and should not be taken as fact.

About a year ago, Intel previewed a new form factor, as a slightly larger brother to the NUC format that they had championed. This new format was called "5x5" in reference to the 5 inch by 5 inch PCB the board used (we'll not get into Metric versus antiquated measurement systems here!). We didn't hear much more about it really, until Computex 2016 at the end of May.

Suddenly, a small bunch of cases and boards appeared, based on Intel socket 1151. As the form factor designed by Intel is very strict, not much variation was had in these new boards, but the cases did show some ingenuity in SFF design.

Read more here.
 

Phuncz

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May 9, 2015
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I think the NUC is an amazing platform but it is ultimately gimped by the CPU and low TDP that's allowed. Mini-STX addresses this by allowing much more powerful CPUs (up to 65W TDP if I'm correct) and the ability to swap them due to the socket.

But since CPU speed is rarely something one might upgrade within the limits of the platform (socket) and the 2-3 year cycle of sockets, I've rarely had the need to upgrade. Even well in the past, except for the time when dual-core and quad-core just came around in the Core 2 Duo/Quad generation.

It doesn't help that CPUs tend to be the most expensive part in a PC of this caliber, so swapping out the CPU should gain you a lot performance or it is just money thrown away.

I feel the socket in this concept is misplaced, it should have been a BGA with desktop chips in five barebone price brackets (CPU, board, case, PSU):
400$ - i7-6700
300$ - i5-6600
250$ - i5-6400
200$ - i3-6100
150$ - G4400

Because the current NUC platform already allows M.2 PCIe storage, 32GB DDR4 and the latest Wireless, so there's not much to gain. The real limitation the NUC platform has, is the limited CPU TDP. Since adding a GPU to mini-STX isn't viable for OEMs, they rarely get mITX done correctly and generally the smallest meaningful GPUs are still 17cm long (mITX sized).

To me, this should have been the "performance NUC" desktop PC, the one people should get that do media creation, photo/video editing in a non-professional context and maybe even gaming. But the OEMs don't seem to know what to do with it. And it's generally just people's ignorance that don't know a powerful system can be small, people are still amazed with the NUCs we have at the office that "that" is a complete PC.

If anything, I am confident AMD would be better off with this platform because they have the APUs, allowing a CPU and GPU upgrade which makes the socket aspect a much more logical choice.
 

EdZ

Virtual Realist
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May 11, 2015
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The missing PCIe slot makes M-STX a bit bizarre. With one included, it would basically be an mITX board shrunk further through swapping to SODIMM and removing the DIMM slot length limitation. Without it, it's a kind of weird kinda-sorta-upgradeable-jumbo-NUC.
It would have been a good opportunity to add a right-angle PCIe slot to the 'top' of the board, or even an MXM slot, to encourage more compact system designs and to very clearly differentiate STX from ITX and NUC by giving it a unique feature.
 

veryrarium

Cable-Tie Ninja
Jun 6, 2015
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confusis said:
M-STX is Intel’s me-too attitude showing again (that’s a story for another time). VIA created ITX and M-ITX almost 15 years ago
I think VIA is given too much credit for the Mini-ITX standard, as FlexATX was specified in 1999 by Intel and there were already 170x170mm FlexATX boards before VIA proposed their Mini-ITX standard in Nov. 2001, such as Shuttle FE22 in Nov. 2000 and Freetech P6F209 in July 2001.
 

veryrarium

Cable-Tie Ninja
Jun 6, 2015
144
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It would have been a good opportunity to add a right-angle PCIe slot to the 'top' of the board, or even an MXM slot, to encourage more compact system designs and to very clearly differentiate STX from ITX and NUC by giving it a unique feature.
I agree since the dimensions of mSTX not allowing mounting-hole compatibility with mITX forces new case designs anyway. And other than a right-angle PCIe slot placed at the top of the board, I also thought of a regular PCIe slot located between the LGA CPU socket and the M.2-occupied area together with a right angle riser would allow a low-profile add-in-card to extend over the bottom end of the mSTX board minimally while not making the thickness of the mSTX enclosure to be not as thick as a typical low-profile-card-compatible slim PCs (somewehere between 90 and 110mm.)
 

IntoxicatedPuma

Customizer of Titles
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Feb 26, 2016
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What does STX offer than the thin ITX boards didnt? Unless this means the death of NUCs and Thin ITX, plus the rise of IRIS graphics on desktop i3 chips...i think stx is a waste
 

Kmpkt

Innovation through Miniaturization
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Feb 1, 2016
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The only reason I could see for Mini STX to exist would be the possibility of adding a 16x PCIe Slot. If I'm not mistaken the length of the pin connector is about 80mm. Once you add the plastic bulk of the socket, you're probably looking at around 100-110mm which is too large for a NUC, but just about right for a Mini STX. With the lower TDP of graphics cards as smaller die processes are utilized (rumoured <75W GTX 1060 this generation), I have to this that this is perhaps a pre-emptive move to provide viable solutions for wearable VR etc.
 
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Hahutzy

Airflow Optimizer
Sep 9, 2015
252
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There's really only one reason why mSTX doesn't have a PCIe slot.

Somewhere in some boardroom inside Intel, someone envisions that the "general public" and "light gamer" demographics' needs can be met by their Iris and Iris Pro line of IGP. This rings true with that claim they had few months ago saying their IGP is "more powerful than 80% of discrete cards" or something.

The mSTX is an effort to push out the possibility of a dGPU being installed, hoping they can gain some grounds in market share of the graphics processor market.

[/tinfoilhat]
 

iFreilicht

FlexATX Authority
Feb 28, 2015
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Do we already know whether an AM4 socket would fit on an mSTX board? If that happens, how will power delivery be handled? For a strong APU, you need a strong power-brick, and I don't think the mSTX barrel connector is made to handle more than 100W of load.

I do agree that it would be the most sensible application of this form-factor.
 

BirdofPrey

Standards Guru
Sep 3, 2015
797
493
I think the reason mSTX exists at all is simple:
The desktop market is contracting, and x86 has no traction whatsoever in the mobile market. Intel is trying to diversify a bit to get more of their chips sold, so they have turned to the mini-PC market. it also helps out their system integrator partners to a degree due to how useful modularity can be for creating a system, and how much money can be saved when some of the engineering work has already been done.

One of the biggest points that attracts customers is upgradability even if most of them never actually use that capability, so it makes sense to pursue that angle a bit even if it makes the board a bit larger. Bear in mind that, even if the board isn't much smaller than mITX, due to the other system constraints, the systems are a fair bit smaller, even if they don't come in as small as NUC or custom systems from OEMs (and a fully custom system will always let you get smaller than a modular one due to the engineering constraints imposed to actually allow for a choice of components, eg. keepout zones).

I still think it's a poor move to not have MXM as an option, though, since the people more likely to value upgradability are also more likely to have additional requirements for add-on boards, especially graphics. Granted, MXM is hard to acquire and isn't that financially viable, but they aren't impossible to source, and it's another check box that would help differentiate these from your standard NUC or barebones mini-PC. I also suspect this form factor is more for system integrators anyways than it is for the general public even if the popularity I have seen might make it viable to sell to the custom market, and sourcing MXM cards isn't as much of a problem for OEMs, plus volume discounts make the parts cheaper.

As for an AM4 system. We'll have to wait and see. I actually wonder about power myself. While they have given Intel shit in the past for space heaters like the pentium 4, AMD hasn't done nearly as much in recent years to improve their power and heat efficiency as their competitors, though they have been getting better reasonably quickly.

===
Frankly, when it comes to small PCs, I think they should look at how companies like Zotac do things. The mainboards on the more powerful systems tend to be a bit larger than this, and their steam machine is even slightly larger than mITX if I am not mistaken, but the layout they use lets them cram the boards, and the cases themselves are still rather thing and the length and width are scarecly larger than the mainboard. Some of them have socketed CPUs or MXM graphics (though most are still soldered). I think much of the space savings has to do with the layout, though: while it's ostensibly for ease of upgrading, all the user replaceable parts are on the underside of the motherboard including the SODIMM slots, any M.2 or mPCIe/mSata, and I have even seen one or two 2.5" drive mountings (and that right there is a killer feature in my eyes, both because mounting directly to the board saves space on cabling and mounting brackets, but it would also let them put an SFF-8639 connector on the motherboard to support U.2 and Sata Express drives in addition to regular SATA drives). Putting everything on the bottom allows the entire topside of the board to be used for motherboard components, and the CPU and GPU and associated cooling equipment.
 

K888D

SFF Guru
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Feb 23, 2016
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I think that a proper gaming APU is needed with far more emphasis on the graphics. CPU's and GPU's have reached an efficiency point where you could quite easily squeeze console beating performance into a single chip of much less than 100W.

Time and time again articles and reviews show that GPU power is much more relevant in determining gaming performance than CPU power in many different scenarios. For instance a 25W Athlon 5350 can perform very well in modern games when accompanied with a capable graphics card, obviously the 5350 is a bottleneck, but the point is that low power CPU's are good enough for modern games if you have enough GPU horsepower.

A well balanced gaming system has a GPU to CPU power consumption in the region of 2:1 in favour of the GPU, examples of this being an Intel i3 with a GTX 950, or an Intel i5 with a GTX 970, etc. In both of these cases the GPU is probably still the bottleneck in most games so you could maybe even push the ratio to 3:1 without bottlenecking.

APU's up to this point have focused massively on CPU performance rather than balancing the CPU to GPU power for gaming. I think there is so much potential for a proper gaming APU, the market would be massive.

Imagine a 90W APU that's split 50:50 CPU to GPU power consumption based on 16nm or 14nm processing, It would be roughly the equivalent of an Intel i3 and a GTX 950 on 1 chip, this could be fairly easily cooled in a chassis of less than 3 Litres, ideal for mSTX form factor.

Laptops are probably the closest thing to doing this where they use low power CPU variants with much higher TDP GPU's, if only they offered something for the desktop with similar TDP ratio's. Maybe ZEN will be the answer?
 
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confusis

John Morrison. Founder and Head writer SFF.N
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Jun 19, 2015
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Wow, didn't expect such a response from this one!

My views on the main points;
-yes, mstx really does need a strong APU. Something like the GTX750ti matched with the 35w i7 that GuilleAcoustic spoke of
-not sure on mxm - that opens up the minefield of how it would be cooled

i will respond in full when I get home this evening. Dang day job!
 

BirdofPrey

Standards Guru
Sep 3, 2015
797
493
Component locations and thicknesses are standardized specifically to allow for a one-size-fits-all cooling solution, so it shouldn't be too difficult to include a compatible cooler with the case assuming mSTX had a single, standard location for MXM modules.

Of course, with a specification for OEMs moreso than consumer, you can always expect vendor specific stuff (MXM allows for vendor custom parts so long as standard parts still fit).

Granted, MXM doesn't always fit like it's supposed to, still, I suggest it because, when you make a form factor specifically because you want something small, the last thing you would want to do is stick on a full sized video card which is almost as much volume than the entire rest of your system. Just look at how much space can potentially be wasted in ITX cases designed to be compatible with the longest and tallest of cards. For regular PCIe expansion slots to actually become viable, we need consistently smaller cards, not just one or two models from a couple of vendors each generation, and it would also be useful if ITC video cards were an actual set of size constraints rather than just a marketing buzzword.
 

dtallon13

Cable Smoosher
Jul 11, 2016
10
1
The missing PCIe slot makes M-STX a bit bizarre. With one included, it would basically be an mITX board shrunk further through swapping to SODIMM and removing the DIMM slot length limitation. Without it, it's a kind of weird kinda-sorta-upgradeable-jumbo-NUC.
It would have been a good opportunity to add a right-angle PCIe slot to the 'top' of the board, or even an MXM slot, to encourage more compact system designs and to very clearly differentiate STX from ITX and NUC by giving it a unique feature.

I really love this idea! I thought I was all alone in thinking of it. I think M-STX should have one of those slots, and there should be an STX GPU specification.


Do you know if there are any of these boards with a Z97 chipset?